Front/Rear Diff Service - DIY

[Sigz]

Hey gang,

After getting the courage to not just replace the main battery of my 22 JT Sport S - but also diving deeper under the main to get to othe aux and replace, it is about time to change the front/rear diff service as my JT is hitting 34k miles.

The dealer who I have free oil changes for life quoted me aroudn $900 to do front/rear/trans service - but after watching a few online Youtube videos - it looks pretty straight forward, and something I can do on my garage floor.

My only concerns and questons are;

1. Since my 22 JT does NOT have a drain plug - I assume I would need to remove the fill hole plug first, and then loosen the top two diff cover bolts, and remove the rest for the oil to drain out?

2. The dif cover should have a gasket - I would assume this is reusable?
2a. Should I invest in a different cover if I plan on DIYing this down the line?

3. The diff cover - can it be cleaned out with parts cleaner? How about the actual differential/teeth area?

4. What is the gold standard/recommended oil to use for a vehicle that doesn't rock crawl, and does some minor light trailer hauling for the front/rear?

5. Should I use YELLOW teflon tape around the fill plug?

6. Does anyone have the torque specs for the bolts?


I've read folks can do this easily at home, and spend about $100 vs $900 from the stealership. I just want to verify everything before I jump in.

Thanks!

-Brent

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[IanNubbit]

Hey gang,

After getting the courage to not just replace the main battery of my 22 JT Sport S - but also diving deeper under the main to get to othe aux and replace, it is about time to change the front/rear diff service as my JT is hitting 34k miles.

The dealer who I have free oil changes for life quoted me aroudn $900 to do front/rear/trans service - but after watching a few online Youtube videos - it looks pretty straight forward, and something I can do on my garage floor.

My only concerns and questons are;

1. Since my 22 JT does NOT have a drain plug - I assume I would need to remove the fill hole plug first, and then loosen the top two diff cover bolts, and remove the rest for the oil to drain out?

2. The dif cover should have a gasket - I would assume this is reusable?
2a. Should I invest in a different cover if I plan on DIYing this down the line?

3. The diff cover - can it be cleaned out with parts cleaner? How about the actual differential/teeth area?

4. What is the gold standard/recommended oil to use for a vehicle that doesn't rock crawl, and does some minor light trailer hauling for the front/rear?

5. Should I use YELLOW teflon tape around the fill plug?

6. Does anyone have the torque specs for the bolts?


I've read folks can do this easily at home, and spend about $100 vs $900 from the stealership. I just want to verify everything before I jump in.

Thanks!

-Brent

Ive reused my gaskets about 5 times now, no issues, just be careful not to pry them and don’t soak then in brake clean

I always have used brake clean everywhere in the pumpkin with no issues and it keeps the fluid cleaner everywhere change and seals and gear wear has been fine

I just use BG 75-140, just use quality gear oil, i stepped up in the weight just because I’m naughtly and am using 3.73s with 37s. All has been swell though

i use liquid teflon on the plugs, just easier to not make a mess and get excess tape everywhere to me

I never torque mine lol, just tight, but just AI sear or google

also I do mean roughly every 15k miles, newrly 90k in and she’s still wuiet and smooth

oh, and if you dont go rock bashing, just stick with the OEM one, have to spend good money for a good flowing aftermarket one for longevity and the drain plug just means you can’t fully clean it out when yoy do fluid changes

 

[Janster]

I’m here for the answers…but actually… Personal opinions here of course.

I don’t know what others will say…but I’m going to say ….. I would NEVER re-use the diff gasket. Cheap insurance, buy a new one.

Clean both gasket surfaces (diff & cover) with parts cleaner, but don’t spray it inside the diff/or around the gears.

 

[ChrisNLA]

Hey gang,

After getting the courage to not just replace the main battery of my 22 JT Sport S - but also diving deeper under the main to get to othe aux and replace, it is about time to change the front/rear diff service as my JT is hitting 34k miles.

The dealer who I have free oil changes for life quoted me aroudn $900 to do front/rear/trans service - but after watching a few online Youtube videos - it looks pretty straight forward, and something I can do on my garage floor.

My only concerns and questons are;

1. Since my 22 JT does NOT have a drain plug - I assume I would need to remove the fill hole plug first, and then loosen the top two diff cover bolts, and remove the rest for the oil to drain out?

2. The dif cover should have a gasket - I would assume this is reusable?
2a. Should I invest in a different cover if I plan on DIYing this down the line?

3. The diff cover - can it be cleaned out with parts cleaner? How about the actual differential/teeth area?

4. What is the gold standard/recommended oil to use for a vehicle that doesn't rock crawl, and does some minor light trailer hauling for the front/rear?

5. Should I use YELLOW teflon tape around the fill plug?

6. Does anyone have the torque specs for the bolts?


I've read folks can do this easily at home, and spend about $100 vs $900 from the stealership. I just want to verify everything before I jump in.

Thanks!

-Brent

1) Always remove the fill plug first.

2) Everyone I have known with a JT/JL that has done their own service has been reusing the factory gasket between changes with no issues. A couple people I know have even reused the gasket when swapping to aftermarket covers. I have some Dana cast iron covers I plan to put on mine during my first diff fluid change.

My JK did not even have gaskets so I just used black RTV and no gasket - which works great if you tear up or don't have a gasket.

3) I don't clean the ring gear / diff with anything usually unless I see abnormal material and need to look closer. I wipe the bottom out with a rag.

4) I buy whatever name brand the auto parts store has at the time in the weight recommended by the manual. I think last time was Valvoline in my JK. Not certain.

5) Oh that's a good question. Not sure what I did about this last time....

6) I didn't even torque mine last time lol. I did not have a torque wrench that goes low enough so just did them by feel. It didn't leak after

 

[Sigz]

Ive reused my gaskets about 5 times now, no issues, just be careful not to pry them and don’t soak then in brake clean

I always have used brake clean everywhere in the pumpkin with no issues and it keeps the fluid cleaner everywhere change and seals and gear wear has been fine

I just use BG 75-140, just use quality gear oil, i stepped up in the weight just because I’m naughtly and am using 3.73s with 37s. All has been swell though

i use liquid teflon on the plugs, just easier to not make a mess and get excess tape everywhere to me

I never torque mine lol, just tight, but just AI sear or google

also I do mean roughly every 15k miles, newrly 90k in and she’s still wuiet and smooth

oh, and if you dont go rock bashing, just stick with the OEM one, have to spend good money for a good flowing aftermarket one for longevity and the drain plug just means you can’t fully clean it out when yoy do fluid changes

Thanks.

It seems some folks just use the brake cleaner on the diff cover VS inside the pumpkin. Not sure if it matters either way? I would assume to make sure all is dried and evaporated before placing new oil in.

I was planning on using Valvoline Flex Fill 75W-90 Full Synthetic Gear Oil 1 QT Squeeze Pouch for the front and rear. Would this be appropriate? Or would 75w-140 be better for the rear since I occasionally "tow a light trailer from time to time?

Do you use the liquid teflon on the plugs and the diff cover bolts?


Thanks.

 

[Pliny]

The instructions that come with the mopar replacement diff cover bolts that have the pre-applied thread sealant:

You're trying to get a nice even squish on the gasket. I've reused the rubber gaskets when I put the new diff covers on and when I had to replace the locker position sensor.

The recommended pattern to use when torqueing the cover bolts:

If you don't already have thread chasing taps to clean the old thread locker out of the bolt holes in the differential housing, get something like this:
thread chasers
That is the set that I bought, there is a smaller metric only kit from the same brand, many others available too. You want those bolt holes to be really clean.

Here is the Spicer part number for the replacement bolt kit: https://www.danaaftermarket.com/10062575
Or you can get the Mopar replacement bolt kit, or try to re-use the original bolts.
Note that 35 Nm is a lot of torque on those little cover bolts.

Thread sealant for the fill plug: https://www.permatex.com/products/t...rmatex-high-temperature-thread-sealant-50-ml/

 

[Supazuk]

I’m here for the answers…but actually… Personal opinions here of course.

I don’t know what others will say…but I’m going to say ….. I would NEVER re-use the diff gasket. Cheap insurance, buy a new one.

Clean both gasket surfaces (diff & cover) with parts cleaner, but don’t spray it inside the diff/or around the gears.

dealers reuse the gasket, and do not stock them

 

[Sigz]

The instructions that come with the mopar replacement diff cover bolts that have the pre-applied thread sealant:

You're trying to get a nice even squish on the gasket. I've reused the rubber gaskets when I put the new diff covers on and when I had to replace the locker position sensor.

The recommended pattern to use when torqueing the cover bolts:

If you don't already have thread chasing taps to clean the old thread locker out of the bolt holes in the differential housing, get something like this:
thread chasers
That is the set that I bought, there is a smaller metric only kit from the same brand, many others available too. You want those bolt holes to be really clean.

Here is the Spicer part number for the replacement bolt kit: https://www.danaaftermarket.com/10062575
Or you can get the Mopar replacement bolt kit, or try to re-use the original bolts.
Note that 35 Nm is a lot of torque on those little cover bolts.

Thread sealant for the fill plug: https://www.permatex.com/products/t...rmatex-high-temperature-thread-sealant-50-ml/

Interesting. The instructions above show both NEW cover gasket and NEW cover bolts. I want to do this the right way, but I'm also wondering if all of that is really needed since every tutorial I've seen to have watched shows them re-using both.

 

[Pliny]

Interesting. The instructions above show both NEW cover gasket and NEW cover bolts. I want to do this the right way, but I'm also wondering if all of that is really needed since every tutorial I've seen to have watched shows them re-using both.

You find it interesting that a company that sells replacement parts would encourage you to buy more replacement parts from them? Which is why I wrote that I have reused the gaskets multiple times. They are some sort of rubber with a metal core. Treat them gently, you don't want to nick or cut the little ribs that are on the surface.

Now for the bolts, the pre-applied thread sealant / thread locker may make a difference to you. Some of the bolt holes in the housing are open on the back side, exposed to water, road salt in the winter if you drive in such places.

That torque spec is for clean bolt holes with new bolts with the pre-applied thread sealant.

Here is the post where I snapped off one of the bolt heads when I was installing the Dana iron diff covers: https://www.jeepgladiatorforum.com/...ng-no-politics-no-gun-talk.23705/post-1562565

The bolts that came with the diff covers were crap. I haven't had any issues with the Mopar bolts or the Spicer ones. The Spicer ones seem like they have an even larger flange than the Mopar ones.

That 35 Nm is a lot of torque for a M8 class 10.9 bolt. The issue I had when considering re-using the old bolts was what to torque them to?

 

[Maximus Gladius]

$900 to do front/rear/trans service

The trans service will eat up most of that cost, but I’m surprised they included the transmission in the quote with only 34K miles. I guess money is money so why not. A better reason to throw that in to is because it’s a rotating component that wears, so it’s just good maintenance.

The diffs are super easy that have reusable gaskets as others have mentioned. The upper bolts on the front cover are a little time consuming to get out as access is tight but the rear ones are much better. You may find locktite on the threads so give the threads a good scrub with a copper brush or use a small pic tool to clean those.

I’ve always used a liberal amount of brake clean (chlorinated) in the pumpkin many, many times (but don’t spray the electrical connections) and all over the teeth. It won’t hurt it at all.

My (new to me) 23 JTR was purchased last December with 16k miles and the first order of maintenance was to change the oil in all rotating components and all samples of oil sent off to the lab for a base line. At only 16k miles, the iron in the front/rear was 416/710ppm. Of course there’s no magnetic drain plug so I’ve placed a 220 pull lb fishing magnet on the cover which now pulls the iron out of the oil.

Careful not to over tighten the bolts, stay at the torque specs mentioned. I’ve even gone less than that using an inch lb bar set to 110 in lbs. The transmission gasket is the very same and those bolts take 98 inch lbs and don’t fall out. So over 300 inch lbs (25 ft lbs/35Nm) seems excessive, but that’s me. I’m not questioning the published torque specs. I’ve not yet had to chase down any bolts that have unwound themselves and fallen out or had to refill the pumpkin or seen oil on my garage floor.

 

[Dave D]

I did the lazy diff change and just pumped it out at 40k. (I know here come the comments)
Front looked like new oil but back was dirty.

 

[JT1]

Thanks.

It seems some folks just use the brake cleaner on the diff cover VS inside the pumpkin. Not sure if it matters either way? I would assume to make sure all is dried and evaporated before placing new oil in.

I was planning on using Valvoline Flex Fill 75W-90 Full Synthetic Gear Oil 1 QT Squeeze Pouch for the front and rear. Would this be appropriate? Or would 75w-140 be better for the rear since I occasionally "tow a light trailer from time to time?

Do you use the liquid teflon on the plugs and the diff cover bolts?


Thanks.

The debate on which weight oil to use will rage on for pages.

I regeared to 5.13 3 years ago, and have just been purchasing the valvoline flex pouch 75-140 for front and rear..
I've replaced it 3 times since and haven't had any issues. I don't think there is enough friction modifier in the valvoline though. First fill I was getting a little bit of noise from the LSD in the back, so I've been adding an ounce of the mopar friction modifier at each fill in the rear.

 

[Guns_N_Rosaries]

All I have to add is to make sure your diff fluid has the correct friction modifiers. I had mine changed at an oil change/mechanic place (a decent one actually), and shortly after they did it, it started grinding. Come to find out the clutch in the back had burned out. Thankfully the dealership replaced it under warranty.

 

[Air Force]

Hey gang,

After getting the courage to not just replace the main battery of my 22 JT Sport S - but also diving deeper under the main to get to othe aux and replace, it is about time to change the front/rear diff service as my JT is hitting 34k miles.

The dealer who I have free oil changes for life quoted me aroudn $900 to do front/rear/trans service - but after watching a few online Youtube videos - it looks pretty straight forward, and something I can do on my garage floor.

My only concerns and questons are;

1. Since my 22 JT does NOT have a drain plug - I assume I would need to remove the fill hole plug first, and then loosen the top two diff cover bolts, and remove the rest for the oil to drain out?

2. The dif cover should have a gasket - I would assume this is reusable?
2a. Should I invest in a different cover if I plan on DIYing this down the line?

3. The diff cover - can it be cleaned out with parts cleaner? How about the actual differential/teeth area?

4. What is the gold standard/recommended oil to use for a vehicle that doesn't rock crawl, and does some minor light trailer hauling for the front/rear?

5. Should I use YELLOW teflon tape around the fill plug?

6. Does anyone have the torque specs for the bolts?


I've read folks can do this easily at home, and spend about $100 vs $900 from the stealership. I just want to verify everything before I jump in.

Thanks!

-Brent

Are you sure you don’t have a Drain plug on lower front side? Mine is there on my 2020 JT REAR DIFF

 

[Sigz]

Are you sure you don’t have a Drain plug on lower front side? Mine is there on my 2020 JT REAR DIFF

Yes, I am posiitve. It appears the JL/JT's of 2021+ had it removed.

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