Automatic Transmission fluid change interval s on 2021 JT

[Nitroexpress]

Attached is the OEM procedures from Tech Authority. Only thing that cannot be reused is the two small nuts for the filter that thread to studs in the pan. New OEM filter will come with new nuts.

The gasket is a rubber molded into metal gasket and is reusable so long as you do not ham fist it out when removing the pan.

OEM filter part number is 68417054AB. This is the one item I would say do not go cheaper aftermarket and spend the coin for the OEM.

Excellent information, thanks!!!

On the fill page from @Hootbro post it states as the last step:
18. Using a diagnostic scan tool, clear any Diagnostic Trouble Codes (DTC).

@Maximus Gladius - Do you think that COULD be what is meant by "reflash"? I know clearing a DTC is not a re-flash or re-learn, but possibly those were a mis-interpretation?

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[Hootbro]

Excellent information, thanks!!!

No problem.

Left out of those OEM instructions is that there is two washer shaped magnets in the circular divots of the pan that will also need to be cleaned of any material when doing the service.

 

[Maximus Gladius]

Excellent information, thanks!!!

@Maximus Gladius - Do you think that COULD be what is meant by "reflash"? I know clearing a DTC is not a re-flash or re-learn, but possibly those were a mis-interpretation?

Just called the shop that did my flush. The “relearn” process is done on a specific tool called a Wi-Tech. It uses internet to connect with Chrysler to wipe all the memory and history so it has a clear slate to relearn. It’s all put back to factory specs

 

[Nitroexpress]

Specifically look for the 850RE transmission. I’m guessing the 8HP models are made in Germany??? The 850Re Is assembled in the US.

I didn't find anything specific to the "RE". I know Chrysler builds these under license from ZF, but I have been using general information produced from ZF.

 

[Nitroexpress]

This morning, I sent the following three questions to ZF via email:

Hello - I would appreciate some help regarding servicing of the transmission listed above. My questions:
- After a filter change and fluid refill, is any type of TCM re-flash or re-learn procedure required?
- Is the metal (not aluminum) pan gasket and fasteners re-usable?
- Is it appropriate to use the vehicles onboard transmission temperature gauge to determine the fluid fill temperature range (86-122 degrees)?

They replied:

A flash or adaption reset is not recommended for a fluid change. Sometimes it can cause problems and is not advised. A gasket and screw replacement is recommended. Most of the time it is easier to use an infrared thermometer. You can zap the oil pan for temp. Although, people do use the dash reading

 

[Maximus Gladius]

Well that just got easier. I know my implosion and early transmission death was due to glycol contamination according to the oil analysis data and not by relearning. Great info though!!

 

[Nitroexpress]

I'm going to order a filter, gasket, pan bolts and fluid. I'm going to do this in my barn, and dammit, I'm going to be successful. Hopefully.... My transmission functions perfect but I'm not one to believe in the 'lifetime' thing and I'm not sold on the flush, and I don't have any faith in a dealership.

I will collect a sample for analysis, mostly because I've nerded out on this topic and I feel it will provide some payback to the community (and Maximus Gladius!).

I'll report back.

 

[Maximus Gladius]

I'm going to order a filter, gasket, pan bolts and fluid. I'm going to do this in my barn, and dammit, I'm going to be successful. Hopefully.... My transmission functions perfect but I'm not one to believe in the 'lifetime' thing and I'm not sold on the flush, and I don't have any faith in a dealership.

I will collect a sample for analysis, mostly because I've nerded out on this topic and I feel it will provide some payback to the community (and Maximus Gladius!).

I'll report back.

Nice! Data points is good. I want to see what the good numbers look like as my analysis shows what an eminent implosion looks like. Is your barn close to Calgary? I’ll come help!

 

[Mac]

How many quarts is a drain and refill for the JT? On my MDX it was 4 quarts or so as I recall, the fluid was $30+ a quart

 

[ecidiego]

Attached is the OEM procedures from Tech Authority. Only thing that cannot be reused is the two small nuts for the filter that thread to studs in the pan. New OEM filter will come with new nuts.

The gasket is a rubber molded into metal gasket and is reusable so long as you do not ham fist it out when removing the pan.

OEM filter part number is 68417054AB. This is the one item I would say do not go cheaper aftermarket and spend the coin for the OEM.

That actually looks super easy. Thanks for posting.

 

[Nitroexpress]

How many quarts is a drain and refill for the JT? On my MDX it was 4 quarts or so as I recall, the fluid was $30+ a quart

I'm gathering it's good to have 6 quarts for this job. I'm still researching that, so I'll report if different.

 

[Maximus Gladius]

I did this write up for those wanting to check their oil level and to also lend support to the video checking fluid level.


There’s two things that take the time.
NOTE** DO NOT pull the fill plug at the transmission when engine is off and frame not level!!! And DON’T pull the drain plug if you have one, leave it alone.
This is not like checking out the diffs or transfer case. When engine is off, the tranny oil sits high above the fill plug.

1. Jack up all 4 corners and level the frame - front to back, side to side. Get the back tires an inch or so off the ground to spin. (This is for checking oil level, you need to spin the gears R N and D a bit as described in the video) if you simply just want to draw out 2-3 ounces and not worry about oil level then have the back end just a bit higher than the front, get transmission up to temperature 86-122F (30-50c) but do it sooner @86F then waiting till 122F window and draw out from the fill plug what you need and put back with fresh oil and CLEAN pump what you take out.

(My garage floor has a 3” tilt north south toward the exit and a 1” tilt east west. Takes me 30 min to get it level with floor Jack and stands.)

Clean any dirt off the fill hole area.

2. Turn the vehicle on, TURN OFF TRACTION CONTROL. Turn on your app screen to show all your temperature gauges and watch the transmission temp. You can pull the fill plug at any time before temp window to see if oil comes out or not. If truck is level and cold, you should see no oil come out. If it does, it’s too full and let it drain out. DON’t collect your sample yet cold. No need to put any fresh oil in now either because you want to draw out whats in there FIRST before adding anything new in. (It would change the analysis if you dump in fresh oil first.)

So watch the temps…you might wait another 30 min to get it up to 86F. When it gets there, pull the FILL plug, oil might dribble out at this point, maybe it won’t. If it dribbles out here (86F) stick in your suction tube and pull out your 2-3 ounce sample. If it DOESN’T dribble here, wait till it does. Again, if oil is coming out at 86F there is no need to put any back in, it’s too full. That oil has so much more expansion to go, your good. So because of the expansion that’s coming, DON’T wait for the temps to get anywhere near 122F to do this. If you’re waiting for temps to reach mid way in the temp window to see oil dribble out, then after you pull sample, put oil back in and install plug.

** Start in the morning with truck cold. Gives you more time.

Now as far as what the guy is taking about at the end of the video concerning oil levels and the cooler and getting the temps hotter for the thermal bypass valve to flow…ignore it, your not doing a flush and working with the cooler oil. You’re just getting out 2-3 ounces and putting fresh stuff back in.

THATS IT. Super simple.

If you see glycol in your analysis, your transmission is done. You can’t save it by doing a flush and it won’t be long before it dies. Just let it go and have it replaced.
—————-

What I would add to this for doing a pan drop is to get a brand new fresh out of the box pressurized garden sprayer that will hold a couple gallons of the tranny oil and only use it for the transmission oil application. You’ll maybe get 3 quarts in the fill hole before oil comes out and once SOMEONE ELSE starts the truck, that pump is going to make those few quarts disappear so you want to be under there shooting in the remainder till it dibbles out. I personally wouldn’t want to start the truck myself, then try to get under there only to find the pump is sucking air and youre trying to get the pressure nozzle up into the fill hole.

 

[Mr._Bill]

The transmission is supposed to be put back in learn mode after a fluid change.

Jeep says the fluid does not need changed. The risk of not having the dealer do a fluid change is losing warranty coverage if the transmission fails.

For anyone who has not read the thread, @MaximusGladius has taken legal action against Jeep Canada and the local Jeep dealer for denying warranty coverage on his transmission. It failed, apparently from Glycol contamination, but he had the fluid changed by a non-dealer shop prior to the failure.

I believe the transmission will last much longer with a fluid change, as recommended by the company that originally designed it. The problem is that Jeep says the version they use with the fluid they provide doesn't need changed under typical operational conditions. This means paying a dealer to do the change, or possibly fighting Jeep in court to get warranty coverage in the event of a failure.

Anyone willing to do the change, without dealer involvement, has to determine how much risk they are willing to accept. You may have no issues with a longer lasting transmission, or you may end up paying for a replacement.

 

[Nitroexpress]

Nice! Data points is good. I want to see what the good numbers look like as my analysis shows what an eminent implosion looks like. Is your barn close to Calgary? I’ll come help!

While I enjoyed a hunting trip to beautiful Northern Alberta this past October, I am bit too far to employ your help on this one. But, a big thanks from Texas for the offer!!

 

[Nitroexpress]

The transmission is supposed to be put back in learn mode after a fluid change.

That statement contradicts ZF's position on this topic. Where do you find this information?

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