Scared for my differentials. Should I be saving for a re-gear?

thuddles

TJ Enthusiast
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Jeeps been sitting for about 2 years, got her up and running, smogged and checked the underside for leaks. didn’t find any. drove it for about 2 weeks and checked again. noticed my pinion seal was leaking. Dropped the diff cover last night to find MAYBE 6oz of fluid. The gears are black but they don't seam damaged. I spray brake cleaner and the color doesn't change much. Smells burnt as all hell. How tolerant are these dana 35's??

So should i be expecting a rebuild in a couple hundred miles?

Gonna put some new fluid in and hope it's all ok.

20/20 hind sight i guess, i went to check the fill plug a few weeks ago, noticed some rtv and no leaks so i just didn't want to mess with it.... :rolleyes:
 
Jeeps been sitting for about 2 years, got her up and running, smogged and checked the underside for leaks. didn’t find any. drove it for about 2 weeks and checked again. noticed my pinion seal was leaking. Dropped the diff cover last night to find MAYBE 6oz of fluid. The gears are black but they don't seam damaged. I spray brake cleaner and the color doesn't change much. Smells burnt as all hell. How tolerant are these dana 35's??

So should i be expecting a rebuild in a couple hundred miles?
Gonna put some new fluid in and hope it's all ok.
20/20 hind sight i guess, i went to check the fill plug a few weeks ago, noticed some rtv and no leaks so i just didn't want to mess with it.... :rolleyes:
If you don't have any noise that's going on I would just put fluid in it and keep going.

If you need to re gear I'd sure be thinking about it it is really really nice when you get one to pull like it should.
 
If you don't have any noise that's going on I would just put fluid in it and keep going.

If you need to re gear I'd sure be thinking about it it is really really nice when you get one to pull like it should.
The only noise i was hearing was a squeak in my front drive shaft. probably the CV, but while i was looking i saw this leak. Glad i caught it in time.

I'm currently running 31's with a 5spd. Will probably want to go to 33's in a few years Im currently at standard 3.5? gears. I'm only in 5th if i'm going down hill, if I regear i'll probably go with 4.8
 
Jeeps been sitting for about 2 years, got her up and running, smogged and checked the underside for leaks. didn’t find any. drove it for about 2 weeks and checked again. noticed my pinion seal was leaking. Dropped the diff cover last night to find MAYBE 6oz of fluid. The gears are black but they don't seam damaged. I spray brake cleaner and the color doesn't change much. Smells burnt as all hell. How tolerant are these dana 35's??

So should i be expecting a rebuild in a couple hundred miles?
Gonna put some new fluid in and hope it's all ok.
20/20 hind sight i guess, i went to check the fill plug a few weeks ago, noticed some rtv and no leaks so i just didn't want to mess with it.... :rolleyes:
If you don't mind the stock gearing a take-off would likely be much cheaper than a regear.
 
If you don't mind the stock gearing a take-off would likely be much cheaper than a regear.
You mean like swap an axel?

I do mind the stock gearing, I would love to be able to use 5th gear and keep the speed i'm going. haha
 
You mean like swap an axel?

I do mind the stock gearing, I would love to be able to use 5th gear and keep the speed i'm going. haha
Yep. A dana 35 could be found in the 100-200 range fairly often. If you go that route though just be sure to pull the cover and check the gears before handing over the money.

If you want an upgrade there's a set of rubicon axles on CR right now. (Northern California) https://sacramento.craigslist.org/pts/d/folsom-jeep-tj-rubicon-dana-44-front/7280189056.html

Edit: after reading it looks like rear is trussed and missing the trackbar mount.
 
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Find a pair of axles for a 4cyl TJ. Instant cheap regear to 4.10
This...but in the mean time put fresh fluid in it and run it.

Or...if you've never done a ring and pinion but mechanically inclined now would be a good time to play with that too and learn.

It's an not an art and most are completely intimidated by.
Today's resources with YouTube you can pretty much learn how to reinvent the wheel.

Hell you can find used ring and pinions that are perfectly fine and even do the job on the cheap.

I echo again...until then fresh fkuid and run em' !!!!

3.55 sucks as a ratio. It really limits the 6 cylinder. Not quite as limiting like a 4 banger but limited none the less. In other words you don't have much room for tire increase/weight addition.

If you want 33's...
Go big or go home. 4.88's

Its better to over gear in these rather than under gear.

Good luck. 👍
 
3.55s are ok with a diesel, so just spend all the money and go that route :). Your gears are probably just fine, but maybe you need some seals.

I can run uphill with 3.07s and 33s, but more gear is better. I went with 3.73, but I might go with 4.10s if I had it all to do over again. We'll see... The good thing is that I've got so many Jeep wheels and tires that are 33in or smaller, so it's free tires during the months I don't need mud tires.
 
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The only noise i was hearing was a squeak in my front drive shaft. probably the CV, but while i was looking i saw this leak. Glad i caught it in time.
I would be way more concerned about the squeaky front driveshaft then any damage you did (doubtful) to the rear axle.
 
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I would be way more concerned about the squeaky front driveshaft then any damage you did (doubtful) to the rear axle.
After looking again, i see a dent in the front drive shaft, i will remove it, have it rebalanced and drive around as a 2 wheeler for a while...
3.55s are ok with a diesel, so just spend all the money and go that route :). Your gears are probably just fine, but maybe you need some seals.

I can run uphill with 3.07s and 33s, but more gear is better. I went with 3.73, but I might go with 4.10s if I had it all to do over again. We'll see... The good thing is that I've got so many Jeep wheels and tires that are 33in or smaller, so it's free tires during the months I don't need mud tires.
If i didn't just pick up a 96 12v then i might..... i would love a 4bt cummins in there though **dreeeaaammm**
To add...4.10's will feel better...
4.56's even better.
4.88's will scream with 31's but with 33's you'll have all 5 gears available even up some hills. It will run the way it should shy of a v8 conversion.
Yeah if i did i would go 4.8 and go to 33's.... lets say 2 years? lol
This...but in the mean time put fresh fluid in it and run it.

Or...if you've never done a ring and pinion but mechanically inclined now would be a good time to play with that too and learn.

It's an not an art and most are completely intimidated by.
Today's resources with YouTube you can pretty much learn how to reinvent the wheel.

Hell you can find used ring and pinions that are perfectly fine and even do the job on the cheap.

I echo again...until then fresh fkuid and run em' !!!!

3.55 sucks as a ratio. It really limits the 6 cylinder. Not quite as limiting like a 4 banger but limited none the less. In other words you don't have much room for tire increase/weight addition.

If you want 33's...
Go big or go home. 4.88's

Its better to over gear in these rather than under gear.

Good luck. 👍
filled both diffs with new royal purple and changed the rear pinion seal, first time doing it for me, you tube was a help but honestly it was super super easy. Had a little trouble hooking my driveshaft back up, but i put the Tcase in neutral and it let me put it into position.



Is it normal for the diffs to only take 1.5 qts of fluid? i could have sworn i read 2.5, i bought 3 qts and didn't even open the third one let alone finish the second.
 
After looking again, i see a dent in the front drive shaft, i will remove it, have it rebalanced and drive around as a 2 wheeler for a while...

Have them rebuild it. When the DC joint in the front shaft seizes up it blows the T-case apart.
 
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Have them rebuild it. When the DC joint in the front shaft seizes up it blows the T-case apart.
Yeah thats why i stopped driving it in the first place. I see your so-cal on Zzyzx, any recommendations for new driveshafts are welcome.
 
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After looking again, i see a dent in the front drive shaft, i will remove it, have it rebalanced and drive around as a 2 wheeler for a while...

If i didn't just pick up a 96 12v then i might..... i would love a 4bt cummins in there though **dreeeaaammm**

Yeah if i did i would go 4.8 and go to 33's.... lets say 2 years? lol

filled both diffs with new royal purple and changed the rear pinion seal, first time doing it for me, you tube was a help but honestly it was super super easy. Had a little trouble hooking my driveshaft back up, but i put the Tcase in neutral and it let me put it into position.



Is it normal for the diffs to only take 1.5 qts of fluid? i could have sworn i read 2.5, i bought 3 qts and didn't even open the third one let alone finish the second.
Of course. Diff cases all have different sizes.A Dana 30 is drastically different than a Dana 50/60....and so on.
Fill it until you can feel fluid with your finger. Replace fill plug...go wheeling.