Pan Drop / Drain & Fill Instructions for ZF 8HP50 or Chrysler TorqueFlite 850RE Automatic Transmission

Maximus Gladius · Mar 31, 2026

Concerning the 23 3.6, the filter for the 850RE is not sold as a single item, it doesn’t have a part #. If you only need the filter, one must buy the whole pan, filter gasket kit…. However, if you check earlier years like 21, the filter is sold separately and has a part # and fits the 23.

g2020 · Mar 31, 2026

Maximus Gladius said:
Concerning the 23 3.6, the filter for the 850RE is not sold as a single item, it doesn’t have a part #. If you only need the filter, one must buy the whole pan, filter gasket kit…. However, if you check earlier years like 21, the filter is sold separately and has a part # and fits the 23.

The Transmission Oil Filter is the same for all Gladiators with either the 8HP50/850RE or the 8HP75 automatic transmission. Please see the following posts. The key takeaway is: "If the kit fits, then the filter fits."

Post #42 in a different thread

Post #13 in this thread

LouisvEarlleJT · Mar 31, 2026

Great write up!

Maximus Gladius · Mar 31, 2026

g2020 said:
The Transmission Oil Filter is the same for all Gladiators with either the 8HP50/850RE or the 8HP75 automatic transmission. Please see the following posts. The key takeaway is: "If the kit fits, then the filter fits."

Post #42 in a different thread
Post #13 in this thread

You connected the dots very well. I’m thinking that’s how you roll.

Gatorac · Apr 4, 2026

Working on this project today. I took the advice of others and pumped fluid out of the fill hole. I went an extra step. I used a piece of bent brake line to make a pickup tube. Used that in the fill hole until I couldn't get anymore out. Removed all but 4 trans pan bolts on the corners. Lowered the pan about 1/4" and stuck the pickup tube through the gap. I was able to get all but about 1/2 cup of fluid out. Cool thing is after the first pump from the syringe stye fluid extractor, the fluid will syphon out. It's not very quick that way but is sure is easy. I did some other chores while waiting for the fluid to extract itself. I spilled less fluid than I did changing my SQ5 8HP trans fluid and it has a drain plug. :CWL:

Siphoning the fluid out of the back corner of the pan.

Jeep Gladiator Pan Drop / Drain & Fill Instructions for ZF 8HP50 or Chrysler TorqueFlite 850RE Automatic Transmission WhatsApp Image 2026-04-04 at 4.25.56 PM

How much was left in the pan once removed.

The tool.

I dropped the exhaust down because I could. It's a Florida Jeep so the bolts came out by hand once loosened.

g2020 · Apr 4, 2026

Gatorac said:
Siphoning the fluid out of the back corner of the pan.

This is my first reply to Gatorac's post. Click here for the second reply.

Nice! I will add this technique to the original post, with credit, as long as it is approved by the committee (one person, @Maximus Gladius).

Update:

The advice on using a J-shaped pickup tube to drain the oil pan has been added to the original post. Please see the following items in each section:

3.22 (Section 3, item 22)
3.23
7.3
Recommendation before 8.7

Maximus Gladius · Apr 4, 2026

g2020 said:
Nice! I will add this technique to the original post, with credit, as long as it is approved by the committee (one person, @Maximus Gladius).

Committee approves!

Maximus Gladius · Apr 4, 2026

Gatorac said:
Working on this project today. I took the advice of others and pumped fluid out of the fill hole. I went an extra step. I used a piece of bent brake line to make a pickup tube. Used that in the fill hole until I couldn't get anymore out. Removed all but 4 trans pan bolts on the corners. Lowered the pan about 1/4" and stuck the pickup tube through the gap. I was able to get all but about 1/2 cup of fluid out. Cool thing is after the first pump from the syringe stye fluid extractor, the fluid will syphon out. It's not very quick that way but is sure is easy. I did some other chores while waiting for the fluid to extract itself. I spilled less fluid than I did changing my SQ5 8HP trans fluid and it has a drain plug.

Siphoning the fluid out of the back corner of the pan.

How much was left in the pan once removed.

The tool.

I dropped the exhaust down because I could. It's a Florida Jeep so the bolts came out by hand once loosened.

Good job!

g2020 · Apr 6, 2026

Gatorac said:
Siphoning the fluid out of the back corner of the pan.

This is my second reply to Gatorac's post. Click here for the first reply.

This is such a good solution that I decided to share some prices.

Brake line: Poly-Armour Domestic PVF Steel Brake Line, 3/8" x 20"; Part # PA-620, $12.99
- I made two J-shaped pickup tubes from this 20" brake line: 12" and 7.5" (the larger size is probably about right)
Tube bender (borrowed at the store): Performance Tool Tubing Bender Up To 3/8" OD; Part # W86013, $20.99
- There are better tube bender options
Optional: Additional plastic tubing
- Vinyl tubing 3/8" ID X 2' @ $1.59/ft = $3.18 (this is 12/32" ID)
- Vinyl tubing 5/16" ID X 2' @ $1.39/ft = $2.78 (this is 10/32" ID)

- Either one of the plastic tube sizes should fit, depending on the brand of syringe that you buy

- On a separate note, 11/32" ID appears to be the correct size for an ATF108 adapter (11/32" ID plastic tubing is difficult to find, even online, but it should be included with a 1500 cc automotive syringe)

- If you are concerned about scratching the oil pan, place a short piece of plastic tubing over the end of the metal pickup tube

I'm still learning how to use a tube bender:

Jeep Gladiator Pan Drop / Drain & Fill Instructions for ZF 8HP50 or Chrysler TorqueFlite 850RE Automatic Transmission J-shaped pickup tube and plastic tubing

PropDr · Apr 30, 2026

g2020 said:
This is a set of written instructions on how to do a pan drop on a Jeep Gladiator or Wrangler 2018+. Reference docs and photos are also included. @Maximus Gladius, coauthor and technical advisor, has performed no fewer than nine pan drops on his two Jeep Gladiators. For more info on the correct fluid for the automatic transmission, see my post on ATF Equivalents.

Pan Drop / Drain & Fill Instructions for ZF 8HP50 or Chrysler TorqueFlite 850RE Automatic Transmission
Based on ZF Process Flow Diagram with Additional Guidance
by @g2020 & @Maximus Gladius

- These instructions also apply to the ZF 8HP75 installed on models equipped with the EcoDiesel 3.0L V6 engine.

DISCLAIMER #1: Perform a pan drop at your own risk. This is not a difficult job, but it needs to be done right.
DISCLAIMER #2: These instructions are for maintenance of the ZF 8HP50 or Chrysler 850RE automatic transmission on a Jeep Gladiator or Wrangler 2018+, and are not intended to fix mechanical issues. Vehicle owner accepts full responsibility whether or not the job is performed correctly.
DISCLAIMER #3: A DIY pan drop may void the 5/60 powertrain warranty in some circumstances, especially outside of the U.S.

Table of Contents

SECTION 1 - PREPARATION
SECTION 2 - PARTS
SECTION 3 - TOOLS
SECTION 4 - TORQUES
SECTION 5 - TEMPERATURES
SECTION 6 - ATF DRAIN #1 of 2
SECTION 7 - ATF DRAIN #2 of 2
SECTION 8 - TRANSMISSION OIL PAN REMOVAL (the actual "pan drop")
SECTION 9 - TRANSMISSION OIL PAN INSTALLATION
SECTION 10 - ATF FILL #1 of 2 (Option A or Option B)
SECTION 11 - ATF FILL #2 of 2 (after ATF fill #1 of 2 has been completed)
SECTION 12 - ATF LEVEL CHECK (after vehicle has completely cooled off overnight)
SECTION 13 - ATF TESTING
SECTION 14 - OPINION
SECTION 15 - RELATED POSTS
SECTION 16 - ATTACHMENTS

SECTION 1 - PREPARATION

Park vehicle in a level position (vehicle frame must be level)

Allow vehicle to completely cool off (overnight)

Wear protective eyewear & gloves

Engage parking brake

Chock tires

This process can be completed WITHOUT raising the vehicle; if vehicle is raised, disable electronic stability control

Ensure that transmission is clean, work area is clean, and garage door is closed to prevent airborne contamination

Use lint-free cloths or paper towels

Work quickly but carefully

Recommended: Document the job with photos

Purchase seven (7) bottles of MOPAR 8 & 9 Speed ATF (68218925AB), ZF LifeguardFluid 9 (AA01.500.001), or equivalent; more may be needed for a vehicle with an aftermarket transmission oil pan

Shake each bottle of ATF for at least 30 seconds before opening

Prior to removing Transmission Skid Plate, use a propane torch or other method to loosen factory sealant on each skid plate fastener

Remove Transmission Skid Plate; reinstall this skid plate after the job is done; for tools & torques, see Section 3 - Tools and Section 4 - Torques below

SECTION 2 - PARTS

1. MOPAR 8 & 9 Speed ATF (68218925AB), ZF LifeguardFluid 9 (AA01.500.001), or equivalent; drainable fluid is 5.0 to 6.5 quarts; 7 quarts should provide one extra full quart; SHAKE each bottle of ATF for at least 30 seconds before opening
2. MOPAR Transmission Oil Filter (68417054AB); this filter fits all gas & diesel models
3. MOPAR Oil Pan Gasket (68522534AA); keep this part on hand as a spare in case existing reusable gasket is punctured, crimped, or torn

Parts for reference only (should be cleaned & reused):

4. MOPAR Transmission Oil Pan and Filter (68362041AC); this kit also includes the gasket (68522534AA); Transmission Oil Pan is not sold individually; for reference only (Transmission Oil Pan should be cleaned & reused)
5. MOPAR Transmission Magnet (68207788AA); there are at least two magnets on the Transmission Oil Pan; for reference only (Transmission Magnets should be cleaned & reused)
6. MOPAR 06510056AA Transmission Oil Pan bolt (with T40 Torx head); for reference only (13 Transmission Oil Pan bolts should be cleaned & reused); keeping a few spare bolts is recommended
7. MOPAR 06104446AA 18 mm Transmission Skid Plate bolts; torque varies, see Section 4 - Torques below (Transmission Skid Plate fasteners should be cleaned & reused)
8. Depending on the model year and/or trim level, your vehicle may also have (one) MOPAR 06104716AA 1/2" Transmission Skid Plate flange nut; torque = 15 ft-lbs (Transmission Skid Plate fasteners should be cleaned & reused)

SECTION 3 - TOOLS

Trans Temp on instrument cluster display (use controls on steering wheel to toggle to Trans Temp)

Bolt tightening sequence diagram (see second attachment: "pan drop 020...")

8 mm Allen socket, for Fill Plug

T40 Torx bit socket, for Transmission Oil Pan bolts

10 mm socket, for Transmission Oil Filter nuts

18 mm socket, for Transmission Skid Plate bolts

1/2" socket, for Transmission Skid Plate flange nut (if applicable)

3" socket extension, for Transmission Skid Plate flange nut (if applicable)

6" socket extension, for Transmission Oil Pan bolts (this extension is required for some of the bolts)

Ratchet

Torque wrench (calibrated in ft-lbs), ONLY for fill plug and skid plate fasteners *** DO NOT USE ft-lb torque wrench for Transmission Oil Pan bolts ***

Torque wrench (calibrated in in-lbs for low-torque applications), for Transmission Oil Pan bolts

Plastic putty knife or trim tool, to remove gasket (may not be required)

Propane torch or other heating tool, to loosen factory sealant on Transmission Skid Plate fasteners

Permatex Threadlocker BLUE Medium Strength part number 24200, for Transmission Skid Plate fasteners; shake tube before use; some shops don't bother with Threadlocker, but this is your call

Automotive fill pump with capacity of at least 2 gallons, such as Motive Power Fill Pro 1745, Orion Motor Tech BBT-D002-N1, or VEVOR YS-059A; use of manual hand pump recommended; use of Schrader valve & air compressor not recommended

Motive has push/handle style pump, Orion has pitcher/lever style pump, and VEVOR also has pitcher/lever style pump

The correct ATF adapter (ATF108, M18x1.5), which is part of a kit, may be bundled with the Orion pump, but it is not included with the Motive or the VEVOR

ATF adapter ATF108, M18x1.5 (part of ACZCR 13-piece ATF adapter kit, ASIN B09ZB4BFRG); a kit that includes this adapter may be bundled with Orion pump BBT-D002-N1

Automotive syringe with extension tube and capacity of 200 cc, such as SEDY 88082; two (2) of these syringes are recommended to prevent contamination: one for extracting, and one for dispensing/filling

Any size syringe may be used, but the 200 cc size makes easy work of adding & removing small amounts of ATF

Large drain tub, such as Lisle 17922 or other drain tub with similar dimensions

Brake cleaner

Lint-free cloths and/or lint-free paper towels

Optional, but recommended: Automotive syringe with extension tube and capacity of 1500 cc, or 1.5 liters, such as VEVOR YS-0113

A large syringe may be used to extract ATF from the Transmission Oil Pan using a J-shaped pickup tube

On a separate note, if ATF adapter and 2-gallon fill pump are not being used, a second large syringe may be used to dispense/fill ATF; in this scenario, using a second large syringe will prevent contamination

Optional, but recommended: A piece of bent (metal) brake line to make a J-shaped pickup tube (credit goes to @Gatorac for posting this technique)

For brake line specifications, tube bending tool, and prices, also see my reply to Gatorac's post

Optional, but recommended in case a bolt breaks: Lisle 61980 - Stripped Screw Extractor Set (set of 10 bits includes 62070 to extract broken T40 Torx bolt) for broken Transmission Oil Pan bolt; also see product details; single bit to extract broken T40 Torx bolt: Lisle 62070 Stripped Screw Extractor #7 (offered for individual sale by Lisle, but shipping costs more than the single bit)

Optional, but recommended: ATF test kit from reputable test lab such as Blackstone or POLARIS (test kit usually shipped at no charge); also see Section 13 - ATF Testing, below

Optional: Additional plastic tubing may be required to remove and install ATF

Exhaust Y-pipe / crossover pipe clearance: It appears that model years after 2021 or 2022 might not have enough exhaust Y-pipe clearance to easily remove & reinstall the Transmission Oil Pan. Only if necessary, detach the right/passenger side (only) of the exhaust Y-pipe (68252391AM Exhaust Pipe and Converter) from the catalytic converter. Of course, reattach the exhaust Y-pipe to the catalytic converter after the Transmission Oil Pan has been reinstalled.

Tools for (slightly) lowering exhaust Y-pipe to remove & reinstall Transmission Oil Pan:

13 mm socket, for two exhaust flange bolts (06105052AA Hex Flange Head Bolt)

The exhaust flange bolt displayed in the exhaust system diagram (06509967AA Hex Flange Head Bolt) is shorter than the original (06105052AA, confirmed) and much more expensive

An aftermarket bolt, nut, & spring option (quantity of 2) is shown in this post by @DanJT (for this option, existing welded nuts may need to be cut off)

Not required: 15 mm 12-point long socket (the nuts are welded to the exhaust flange, and are not specified in the exhaust system diagram)

Ratchet (this tool is already listed above)

Torque wrench (calibrated in in-lbs) (this tool is already listed above)

Torque = 156 in-lbs (13 ft-lbs), as listed in the torque spreadsheet provided on this forum; use of an in-lb torque wrench is recommended

Detaching the exhaust Y-pipe from the catalytic converter (only) will allow an extra 1/4" of clearance for removing & reinstalling the Transmission Oil Pan; this small amount of extra clearance can make a big difference, especially when reinstalling the Transmission Oil Pan & gasket

If this technique still does not provide enough clearance, please advise in the comments

SECTION 4 - TORQUES

1. Automatic transmission Fill Plug: 26 ft-lbs

2. Transmission Oil Pan bolts (13 bolts):

A. Follow proper bolt tightening sequence (see diagram in second attachment: "pan drop 020...")
B. Torque round 1 (ONE-HALF torque): 48 in-lbs (use proper bolt tightening sequence) AND (use torque wrench calibrated in in-lbs)
C. Torque round 2 (final/full torque): 96 in-lbs (use proper bolt tightening sequence) AND (use torque wrench calibrated in in-lbs)

3. Transmission Oil Filter nuts: No torque; use the technique described in Section 9 - Transmission Oil Pan Installation

4. Transmission Skid Plate fasteners:

A. 3-bolt configuration: 48 ft-lbs (one bolt in middle), and 52 ft-lbs (two bolts; one to frame on each side)
B. 4-bolt + 1 flange nut configuration: 55 ft-lbs (four bolts), and 15 ft-lbs (one flange nut to fuel tank); please verify the torques for this configuration

5. Exhaust flange bolts: 156 in-lbs (13 ft-lbs); use of an in-lb torque wrench is recommended

SECTION 5 - TEMPERATURES

Automatic transmission temperature must be below 86°F before starting process (below 30°C)

Automatic transmission temperature must be between 86°F and 122°F during timed shifting sequence AND level check (between 30°C and 50°C)

SECTION 6 - ATF DRAIN #1 of 2

Before starting this process, temperature of automatic transmission must be below 86°F (see Trans Temp on instrument cluster display)

Do NOT start engine

Place large drain tub under transmission

Drain ATF by removing fill plug using 8 mm Allen socket & ratchet; this is the drainable ATF located above the fill hole (1.5+ quarts)

Proceed to ATF Drain #2 of 2

SECTION 7 - ATF DRAIN #2 of 2

Extract ATF, using 200 cc syringe (for extracting ATF), by inserting narrow plastic tube into the fill hole, down and toward the rear of the transmission, until it touches any component in (or the bottom of) the Transmission Oil Pan; do not force plastic tube to the bottom; this is the drainable ATF located below the fill hole (3.5+ quarts)

Extracting some of the ATF before dropping (removing) Transmission Oil Pan is optional, but doing so allows for less splash when removing the pan

Note: Also see "Recommendation" in the next section

If sending ATF to a lab to be tested (recommended), take a sample during this extraction process

If taking a break, reinstall fill plug finger tight (do not torque fill plug yet)

Proceed to Transmission Oil Pan Removal (the actual "pan drop")

SECTION 8 - TRANSMISSION OIL PAN REMOVAL (the actual "pan drop")

1. Before removing Transmission Oil Pan, use brake cleaner to thoroughly clean exterior of oil pan and areas around edges of oil pan
2. Transmission Oil Pan is reusable, but it must be cleaned, the magnets must be cleaned, and the filter must be replaced
3. Oil Pan Gasket (MOPAR 68522534AA) is reusable, but it must be cleaned with a lint-free cloth
- If performing a series of pan drops within a short period of time (minimum of 500 miles between each pan drop), Oil Pan Gasket should be replaced A) during the last pan drop, or B) during a preceding pan drop if damage to gasket is found
4. Keep new gasket on hand in case existing gasket is punctured, crimped, or torn
5. Transmission Oil Filter (MOPAR 68417054AB) must be replaced
- If performing a series of pan drops within a short period of time (minimum of 500 miles between each pan drop), Transmission Oil Filter may be replaced A) every time (optimal), B) every other time (reasonable), C) on a first & last pan drop basis (economical), or D) on a last pan drop basis (more economical); during a series of pan drops, a clean filter is important, but increasing the concentration of new ATF is most important; "optimal" option recommended by @Maximus Gladius, "reasonable" option mentioned by @Hootbro, and other options suggested by @g2020
6. Transmission Magnets (68207788AA) are reusable, but they must be cleaned

Recommendation: Before continuing with this part of the process, consider using a J-shaped pickup tube to extract almost all of the ATF remaining in the oil pan. This is optional, but it will reduce mess. Credit goes to @Gatorac for sharing this technique. Start by keeping the bolts in the four corners loosened, but not removed, to create enough space to insert the tube. The J-shaped pickup tube should maintain contact with the bottom of the oil pan.

7. Carefully remove thirteen (13) Transmission Oil Pan bolts (MOPAR 06510056AA) using T40 Torx bit socket & ratchet
8. Loosen bolts in four corners first, and remove them last
9. Note: When installing Transmission Oil Pan later, follow proper bolt tightening sequence
10. Carefully remove Transmission Oil Pan (if at least some ATF in the pan was extracted, there will be less spill)
11. Remove Transmission Oil Filter nuts from Transmission Oil Pan using 10 mm socket & ratchet, then remove Transmission Oil Filter
12. Remove Transmission Magnets from Transmission Oil Pan, inspect metallic sludge, and clean off the magnets using a lint-free cloth; fine particles in the sludge are normal
13. Carefully remove Oil Pan Gasket and clean it using a lint-free cloth; remove it using a plastic putty knife & minimal force to avoid bending or otherwise damaging the gasket
14. Clean the Transmission Oil Pan using brake cleaner and a lint-free cloth
15. Clean transmission flange (gasket mating surface, which is metal) using brake cleaner sprayed into a lint-free cloth
16. Proceed to Transmission Oil Pan Installation

SECTION 9 - TRANSMISSION OIL PAN INSTALLATION

1. Install new Transmission Oil Filter and new Transmission Oil Filter nuts (included with filter)
2. When installing Transmission Oil Filter, use 10 mm socket & ratchet to turn each (new) Transmission Oil Filter nut until it makes contact, then LOOSEN nut one-half turn (to allow filter to move horizontally but NOT vertically)
3. As a check on correct filter movement, Transmission Oil Filter should be "unconstrained on horizontal plane"
4. Easy-to-miss (metal filings): Use brake cleaner and a lint-free cloth to carefully clean the nuts, bolts and Transmission Oil Pan, wiping away any metal filings released by the new nuts
- This step prevents "instant contamination" that occurs just by installing the filter
- The nuts have a different thread grip and are for onetime use; do not reuse/reinstall the nuts
5. Apply thin coat of new ATF to filter O-ring (O-ring comes already installed in its proper place)

6. Place clean magnets in original locations on Transmission Oil Pan

7. Fit the four rubber stubs on the Oil Pan Gasket into the slots in the Transmission Oil Pan
8. If necessary, pull exhaust Y-pipe down slightly (1/4") to allow extra clearance for replacing Transmission Oil Pan (to detach exhaust Y-pipe from catalytic converter, see end of Section 3 - Tools)
9. Align Transmission Oil Pan & Oil Pan Gasket with transmission flange
10. Follow proper bolt tightening sequence to torque Transmission Oil Pan bolts (see bolt tightening sequence diagram in second attachment: "pan drop 020...")
11. *** IMPORTANT: Use an INCH-POUND TORQUE WRENCH to tighten Transmission Oil Pan bolts ***
12. Torque round 1 (ONE-HALF torque): Carefully install Transmission Oil Pan & gasket using a T40 Torx bit socket & INCH-POUND TORQUE WRENCH, the proper bolt tightening sequence, and ONE-HALF torque (48 in-lbs)
13. Torque round 2 (final/full torque): Carefully tighten each Transmission Oil Pan bolt using a T40 Torx bit socket & INCH-POUND TORQUE WRENCH, the proper bolt tightening sequence, and FULL torque (96 in-lbs)
14. Proceed to ATF Fill #1 of 2 (Option A or Option B)

SECTION 10 - ATF FILL #1 of 2 (Option A or Option B)

1. Before starting this part of the process, temperature of automatic transmission must be below 86°F (see Trans Temp on instrument cluster display)
2. Before opening any bottle of ATF, SHAKE each bottle of ATF for at least 30 seconds to remix important additives that are known to settle to bottom of bottle

Note: Steps 1 & 2 above apply to both Option A and Option B

Option A (requires 2 people): Follow these steps if you are NOT using an ATF adapter (ATF108, M18x1.5) and a 2-gallon fill pump (or larger)

3. Do NOT start engine
4. Remove fill plug using 8 mm Allen socket & ratchet
5. Using 200 cc syringe (for dispensing ATF), install ATF until it drips over bottom edge of fill hole (3.5+ quarts for this first of two fills)
- When not using an ATF adapter, a 1.5-liter syringe, such as the VEVOR YS-0113, may be a better option for dispensing/filling the ATF
- For dispensing/filling, I have not recommended the 1.5-liter syringe because, for less than $100, the combination of ATF adapter ATF108 and a 2-gallon fill pump (Option B, below) allows the ATF to be installed without any air entering the transmission
6. Reinstall fill plug finger tight (do not torque fill plug yet)
7. Proceed to beginning of SECTION 11 - ATF Fill #2 of 2

Option B (no helper required): Follow these steps if you are using an ATF adapter (ATF108, M18x1.5) and a 2-gallon fill pump (or larger)

3. Do NOT start engine
4. Ensure that plastic fluid transfer tube is properly installed on fill pump
5. Unscrew cap from oil pour point on fill pump and add 5 quarts, plus 50 cc, of new ATF
- 50 cc = 1.7 fl oz, or slightly less than 1/4 cup; an extra 50 cc of ATF is necessary because this amount remains in the pump and the plastic tube after the ATF is completely transferred to the transmission
- Reminder: SHAKE each bottle for at least 30 seconds)

6. Refasten cap

7. Remove fill plug using 8 mm Allen socket & ratchet
8. Install ATF adapter (ATF108, M18x1.5) finger tight, plus a quarter-turn so it doesn't leak
9. Attach plastic tube to ATF adapter
10. Pump the ATF until all of it has been transferred to the transmission (5+ quarts for this all-in-one fill)

11. Start engine
12. Remove ATF adapter
13. If ATF comes out of fill hole, do not be alarmed; this means that the transmission was overfilled
14. Using quick-release adapter (should be provided in adapter kit) or 200 cc syringe (for dispensing ATF), add ATF until it drips over bottom edge of fill hole
15. Reinstall fill plug finger tight (do not torque fill plug yet)
16. Proceed to Step #7 in SECTION 11 - ATF FILL #2 of 2

SECTION 11 - ATF FILL #2 of 2 (after ATF fill #1 of 2 has been completed)

Note: If you are performing an ATF LEVEL CHECK and do not expect to add a large amount of ATF (less than a pint, or possibly no fluid at all), you should not need a helper. Prepare your tools, work quickly & safely, and proceed to Step #1.

IMPORTANT (for ATF FILL #2 OF 2): It is best to have two people involved: One person in the driver's seat ready to start the engine, and a second person underneath the vehicle to remove the fill plug and install the ATF as soon as the engine is started. The main goal here is to NOT to allow the transmission pump to suck air (after the engine is started): IMMEDIATLELY after the fill plug is removed, install the ATF as described in the following steps.

If you do not have a helper, prepare your tools and complete the first six steps as quickly & safely as possible.

Before starting engine, temperature of automatic transmission must be below 86°F (see Trans Temp on instrument cluster display)

Before starting engine, vehicle frame must be level

Start engine

Remove fill plug using 8 mm Allen socket & ratchet

This step depends on whether you are completing ATF FILL #2 OF 2, or an ATF LEVEL CHECK

ATF FILL #2 OF 2: Install ATF until it drips over bottom edge of fill hole (1.5+ quarts for this second of two fills)

ATF LEVEL CHECK: Using your finger, check fluid level and, if necessary, add ATF until it drips over bottom edge of fill hole

Reinstall fill plug finger tight (do not torque fill plug yet)

For remainder of process, transmission temperature must be between 86°F and 122°F

When transmission temperature reaches 86°F, start the following timed shifting sequence

Firmly depress brake pedal, shift to N, and rev engine at 2,000 rpm for 30 seconds to fill torque converter

PAUSE: Before proceeding to next step, let engine come down to idle speed

Firmly depress brake pedal, shift to P, and let engine idle for 10 seconds

Firmly depress brake pedal, shift to R, and let engine idle for 10 seconds

Firmly depress brake pedal, shift to N, and let engine idle for 10 seconds (not specified in ZF process flow, but recommended)

Firmly depress brake pedal, shift to D, and let engine idle for 10 seconds

Firmly depress brake pedal, shift to D1 (manual), and let engine idle for 10 seconds

Firmly depress brake pedal, shift to D2 (manual), and let engine idle for 10 seconds

Firmly depress brake pedal, shift back to N, and pause briefly (not specified in ZF process flow, but recommended)

Firmly depress brake pedal, shift back to P, and let engine idle

Confirm temperature of automatic transmission is between 86°F and 122°F; completing this process on the cooler side of the temperature range is better because cooler ATF takes up less space and installing it just above 86°F maximizes the amount of ATF that is installed

If transmission temperature is near 122°F or higher, stop and restart timed shifting sequence at temperature of 86°F

Remove fill plug

If fluid level is low, add ATF until it drips over bottom edge of fill hole

Reinstall fill plug, using 8 mm Allen socket and torque wrench, with torque of 26 ft-lbs

Check transmission for leaks

Test drive vehicle to normal operating temperature

Allow vehicle to completely cool off (overnight)

Proceed to "ATF Level Check (after vehicle has completely cooled off overnight)"

SECTION 12 - ATF LEVEL CHECK (after vehicle has completely cooled off overnight)

IMPORTANT: While the engine is running and the ATF LEVEL CHECK is being completed, ATF should not come out of the transmission. If it does, do not be alarmed. This means that the transmission was overfilled. Continue the ATF LEVEL CHECK procedure. Next, you will be redirected to the previous section.

NOTE: The steps for the ATF LEVEL CHECK procedure are the same as the first 25 steps in SECTION 11, including Step #5.2. If you are only doing an ATF LEVEL CHECK (not the entire pan drop process) and the transmission was overfilled at the factory, advise your Jeep dealer.

ATF LEVEL CHECK procedure:

Complete steps 1 thru 25 in SECTION 11 (for Step 5, follow Step #5.2)

SECTION 13 - ATF TESTING

Optional but recommended: Obtain ATF test kit from reputable test lab, such as Blackstone or POLARIS (test kit usually shipped at no charge)

For important testing tips, see section called "Testing" in my post on ATF Equivalents

SECTION 14 - OPINION

"No-Drop" and "Pan Drop Light" Options
by @g2020

I believe that a pan drop is necessary only as often as recommended by ZF. A pan drop is a nickname given to a drain & fill, using gravity only, in which the Transmission Oil Pan is removed, the parts are cleaned or replaced, and new ATF is installed.

The service interval recommended by ZF is 93,000 miles for a ("daily driver") vehicle that has never been off-road, towed a trailer, or faced other severe conditions. For severe duty including off-road use and trailer towing, the service interval is every 42,000 miles +/- 5,000 miles (my estimate). ZF also recommends changing the ATF in the automatic transmission in the case of "unknown vehicle use", or when purchasing a used vehicle. The service intervals mentioned here are not set in stone. Do what you believe is best for your vehicle given your driving and maintenance habits.

The following two limited, or light, versions of a (full) pan drop are not my original ideas, but they should be mentioned in this post.

No-drop (ATF-only) option: For those of us who want to maintain the transmission without dropping the pan every time, there is a "no-drop" (fluid-only) drain & fill option: Just skip Sections 8 & 9 (Transmission Oil Pan removal & installation) in this post. A clean filter & clean magnets are important, but increasing the concentration of new ATF is most important. Performing a single "no-drop" will replace about 20% of the (original) ATF, three (3) no-drops will replace about 45%, and five (5) will replace about 65%. These estimates take into account a small amount of ATF being extracted from below the fill hole. Drive a minimum of 500 miles between each job.

In contrast, the estimated ATF replacement rates for a (full) pan drop are 50% after one job, 80% after two jobs, and 90% after three jobs (5 quarts drained each time). These results are lower than those shown in ATF Equivalents (6.5 quarts drained each time) and my reply to a different thread (5.5 quarts drained each time). Results may vary, but you should be able to drain at least five quarts during each (full) pan drop.

Pan drop light (no filter replacement) option: If you don't mind dropping the pan each time, the same ATF replacement rates associated with a full pan drop are achieved by dropping the Transmission Oil Pan, cleaning & reinstalling the magnets, and installing new ATF. This "light" version of a pan drop maximizes the concentration of new ATF, removes metal particles captured by the magnets, and saves some time & money by skipping the filter replacement. Once again, drive a minimum of 500 miles between each job.

Avoid being lulled into thinking that a "no-drop" or a "pan drop light" can extend the (full) pan drop service interval. Over time, the filter becomes clogged and the magnets gather mounds of fine metallic particles. These two limited options will replenish additives between (full) pan drops, but a (full) pan drop must still be performed according to the pan drop service interval. Never do a transmission flush.

On the subject of transmission service intervals, I don't trust advice from Jeep dealers because between 2019 and 2025, several dealers swore up-and-down that the ATF in the transmission is a lifetime fluid (the company line). Then, in December 2025, my local Jeep dealer sent me a flyer in the mail recommending that I get a transmission service.

Do your research and then decide what is right for your vehicle.

SECTION 15 - RELATED POSTS

Specific: ATF Equivalents
Specific: Pan Drop Performed by a Jeep Dealership (Including Invoice)
Specific: Fluid Level Check, Transmission Cooler Lines, and Thermostatic Bypass Valve (TBV)
Specific: My Monthly Maintenance: Power Steering, Automatic Transmission, Radiator (more details on "no-drop")

Related: Manufacturer Specifications
Related: Links to Prices

General: Oils, Fluids & Filters -- Lists & Guides For Jeep Gladiator

SECTION 16 - ATTACHMENTS

The following 15 attachments cover many of the key steps in the pan drop process.

The guides & diagrams in the first four attachments are useful as reference docs, but each doc also contains at least some content that is outdated (torque spec), nonspecific (process flow diagrams), or unnecessary (raise vehicle). In this post, only current info applicable to a DIY pan drop is used.

The remaining 11 files, starting with "pan drop 050...", are photos taken by @Maximus Gladius of the pan drop that he completed in December 2025.

File names:

Note: Original estimates of drain & fill volumes, embedded in some of the following file names, have been revised: "2 to 3 quarts" (original) = 1.5+ quarts (revised), and "3 to 4 quarts" (original) = 3.5+ quarts (revised)

pan drop 010 ZF Service Information Oil change kit for ZF 8HP automatic transmission November 2024 original file name 50130 EN.pdf

pan drop 020 8HP50 850RE versions of diagram 3647070 Transmission Oil Pan Bolt Tightening Sequence & Torque Specification sources MOPAR FCA Tech Authority originally posted by Hootbro and update provided by Maximus Gladius.png

pan drop 030 MOPAR FCA Instruction Sheet K6856018 Transmission Oil Filter Replacement 850RE 8HPXX with Steel Transmission Oil Pan page 1 of 2 steps 01 thru 08 text only credit Maximus Gladius 2025-12-30.jpg

pan drop 040 MOPAR FCA Instruction Sheet K6856018 Transmission Oil Filter Replacement 850RE 8HPXX with Steel Transmission Oil Pan page 2 of 2 steps 09 thru 11 text & bolt tightening sequence diagram credit Maximus Gladius 2025-12-30.jpg

pan drop 050 old fluid above fill hole (2 to 3 quarts) draining thru fill hole prior to removing transmission oil pan credit Maximus Gladius 2025-12-30.jpg

pan drop 060 old fluid above fill hole (2 to 3 quarts) draining thru fill hole prior to removing transmission oil pan credit Maximus Gladius 2025-12-30.jpg

pan drop 070 old fluid below fill hole (3 to 4 quarts) being extracted thru fill hole to empty the transmission oil pan (and for test sample sent to laboratory) prior to removing transmission oil pan credit Maximus Gladius 2025-12-30.jpg

pan drop 080 use brake cleaner to clean around transmission before removing transmission oil pan credit Maximus Gladius 2025-12-30.jpg

pan drop 090 detached MOPAR transmission oil pan & gasket (MOPAR 68522534AA) before being completely removed credit Maximus Gladius 2025-12-30.jpg

pan drop 100 850RE automatic transmission with oil pan and gasket removed and flange (gasket mating surface) cleaned credit Maximus Gladius 2025-12-30.jpg

pan drop 110 inside of reusable MOPAR transmission oil pan with 2 magnets (MOPAR 68207788AA) & filter (MOPAR 68417054AB) intact credit Maximus Gladius 2025-12-30.jpg

pan drop 120 metallic sludge accumulated on 1 of 2 transmission magnets (MOPAR 68207788AA) credit Maximus Gladius 2025-12-30.jpg

pan drop 130 metallic sludge accumulated on 1 of 2 transmission magnets (MOPAR 68207788AA) credit Maximus Gladius 2025-12-30.jpg

pan drop 140 inside of reusable MOPAR transmission oil pan after cleaning shown with clean magnets & without filter installed credit Maximus Gladius 2025-12-30.jpg

pan drop 150 new fluid being installed thru fill hole after installing clean transmission oil pan & new gasket & new filter & clean magnets credit Maximus Gladius 2025-12-30.jpg

Note: The first file (pan drop 010...) is attached at the end of this post because it is a six-page document
Full file name:
pan drop 010 ZF Service Information Oil change kit for ZF 8HP automatic transmission November 2024 original file name 50130 EN.pdf

Attachments, continued:

pan drop 020 8HP50 850RE versions of diagram 3647070 Transmission Oil Pan Bolt Tightening Sequence & Torque Specification sources MOPAR FCA Tech Authority originally posted by Hootbro and update provided by Maximus Gladius.png

pan drop 030 MOPAR FCA Instruction Sheet K6856018 Transmission Oil Filter Replacement 850RE 8HPXX with Steel Transmission Oil Pan page 1 of 2 steps 01 thru 08 text only credit Maximus Gladius 2025-12-30.jpg

pan drop 040 MOPAR FCA Instruction Sheet K6856018 Transmission Oil Filter Replacement 850RE 8HPXX with Steel Transmission Oil Pan page 2 of 2 steps 09 thru 11 text & bolt tightening sequence diagram credit Maximus Gladius 2025-12-30.jpg

pan drop 050 old fluid above fill hole (2 to 3 quarts) draining thru fill hole prior to removing transmission oil pan credit Maximus Gladius 2025-12-30.jpg

pan drop 060 old fluid above fill hole (2 to 3 quarts) draining thru fill hole prior to removing transmission oil pan credit Maximus Gladius 2025-12-30.jpg

pan drop 070 old fluid below fill hole (3 to 4 quarts) being extracted thru fill hole to empty the transmission oil pan (and for test sample sent to laboratory) prior to removing transmission oil pan credit Maximus Gladius 2025-12-30.jpg

pan drop 080 use brake cleaner to clean around transmission before removing transmission oil pan credit Maximus Gladius 2025-12-30.jpg

pan drop 090 detached MOPAR transmission oil pan & gasket (MOPAR 68522534AA) before being completely removed credit Maximus Gladius 2025-12-30.jpg

pan drop 100 850RE automatic transmission with oil pan and gasket removed and flange (gasket mating surface) cleaned credit Maximus Gladius 2025-12-30.jpg

pan drop 110 inside of reusable MOPAR transmission oil pan with 2 magnets (MOPAR 68207788AA) & filter (MOPAR 68417054AB) intact credit Maximus Gladius 2025-12-30.jpg

pan drop 120 metallic sludge accumulated on 1 of 2 transmission magnets (MOPAR 68207788AA) credit Maximus Gladius 2025-12-30.jpg

pan drop 130 metallic sludge accumulated on 1 of 2 transmission magnets (MOPAR 68207788AA) credit Maximus Gladius 2025-12-30.jpg

pan drop 140 inside of reusable MOPAR transmission oil pan after cleaning shown with clean magnets & without filter installed credit Maximus Gladius 2025-12-30.jpg

pan drop 150 new fluid being installed thru fill hole after installing clean transmission oil pan & new gasket & new filter & clean magnets credit Maximus Gladius 2025-12-30.jpg

One hell of a write up.
Very helpful, thanks!

Superbike1 · May 18, 2026

Just used this thread. Awesome description and explanation! 93110 miles and my fluid looked ok and my magnets looked like the ones in the photos. Everything was cleaned and reinstalled and driven today about 50 miles. It still drives as it did before. No difference as far as I can tell except peace of mind!

Pan Drop / Drain & Fill Instructions for ZF 8HP50 or Chrysler TorqueFlite 850RE Automatic Transmission

Maximus Gladius

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g2020

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Maximus Gladius

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g2020

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Maximus Gladius

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