Revolution 5.38 Pinion Blew Up

C

CO_love

New member
I had a 5.38 Revolution gear and pinion put in, about 3 years ago (so it's outside of the warranty!). After some grinding noise that went along with the rotation of the wheels, I popped the rear diff cover to find a lot of metal in there. I put the cover back on, took it to a different shop than the one that installed the gear and had them look to make sure everything was installed properly, it was. They're telling this is what happens when you put a 5.38 in a Dana 44. They're recommending that I drop down to a 4.88 and change the TCase.

It's an 05 tj rubi with 70,000 miles on it. There are maybe 15,000 miles on the new gears. I've wheeled it maybe twice with the new gears. I mostly wheel in rocks, cause that's what Colorado has. It's on 37 tires. The Dana 44 is original. The first time I heard the noise was on the street, not the trails, so I don't believe the pinion was damaged on the trail (dunno).

My questions are:
1) Did I just get unlucky and I should replace the 5.38 with another 5.38?
2) I live and wheel in Colorado, wouldn't 4.88 be too high? My biggest issue is that I have a manual & I'm attempting to not burn up the clutch in the rocks.
3) Is it worth replacing the TCase?
4) Do you agree with going down to a 4.88 & swapping the TCase or should I do something different? Suggestions appreciated!

Thank you in advance!
IMG_20200320_165840.jpg
 
fiend said:
Split the difference. Consider 5.13.

5.38 pinion in a 44 is small and weak. Failure point.
Click to expand...

That's what I said, but they told me the 5.13 is just slightly larger than the 5.38, that neither of them should be in a Dana 44. That true?
 
CO_love said:
That's what I said, but they told me the 5.13 is just slightly larger than the 5.38, that neither of them should be in a Dana 44. That true?
Click to expand...

5.13 will be larger per say because it has less and bigger teeth than a 5.38 ratio. 5.13 is really the largest you should go in a d44.
 
CO_love said:
That's what I said, but they told me the 5.13 is just slightly larger than the 5.38, that neither of them should be in a Dana 44. That true?
Click to expand...

Plenty of people, myself included, have successfully run 5.13s in a 44 with 37s. Unless you’re running a V8 conversion or you lack even a modicum of finesse, it should be fine.


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I wouldn’t go over 4.88 in a tj (4.56 on non rubicons with a d30 front) there’s just not enough metal, one mans opinion. Stock lockers I assume?
Leave the t case alone.
I wouldn’t worry about the clutch the ones they use can take a serious beating when necessary.


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TJs don’t have the thick cut gear set that the jk d44 axles have, and the front d44 in a TJ/LJ Rubicon is a low pinion which makes it inherently weaker in a front axle. I don’t have any experience with TJs at that level (mine was relatively stock when I had one back in 2004) but Imwith the TJ/LJ Alex specs I can see their reasoning with recommending 4.88s.


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CO_love said:
what are people's thoughts on using the Jana K4 or the Nitro kit to make the TJs D40 as strong as the JKs?
http://www.jantz4x4.com/jantz.php?p=detail&pro=jana_k4
https://www.justdifferentials.com/PKD44-BP-p/pkd44-bp.htm

Write up:
https://www.pirate4x4.com/forum/axles-tires-wheels/957491-jana-k4-installing-new-sckool-jk44s-your-old-school-housing.html
Click to expand...

I wouldn’t bother. The tj 44s are plenty strong, A 4.0l manual and 4.88s are enough for 37s. I know guys that wheel 37s on smaller gears and never have a problem. Your Jeep though, do what you want.


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