Trying to understand my rear differentials

Spic

Spic

TJ Enthusiast
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Jun 14, 2018
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Im trying to understand what diff's I have incase I need to rebuild due to a noisy drivetrain, am I right in thinking I have a front Dana 30, and a rear Dana 44, my build sheet says it came out the factory with 3.07 gears
First pic is front differential.

20180818_104835.jpg


20180818_104615.jpg
 
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You are correct. Rear is a Dana 44.
 
T
JMT said:
You are correct. Rear is a Dana 44.
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Thanks for the reply, so is it normal to have a Dana 30 in the front and a Dana 44 in the rear ? Or is there a chance someone has changed on of the axles and in which case has wound it up ?
 
So just took the cover off and found this,what a fxxkxx, one tooth has snapped off, everything in and around it is really nice and tight, no play at all which I wasn't expecting

20180818_121123.jpg
 
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It's fairly common. The Rubicon has D44s both front and rear, and the lesser models ran either Dana 44 rear/Dana 30 front, or Dana 35 rear/Dana 30 front. The Dana 44 rear is the preferred axle, though the 3.07 gearing is the least desirable of the ratios, generally speaking.
 
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From what I understand, all TJ’s (97-06) that came with a Dana 44 rear and Dana 30 front were geared with a 3.73 ratio. If yours came from the factory with a Dana 35 rear with 3.07 ratio and someone upgraded it to a Dana 44 rear from a TJ, then it would have been silly to regear the rear to 3.07. If the donor was a 3.73 ratio, then they most likely regeared the front to 3.73, or whatever the rear Dana 44 donor axle was geared at.

You should be able to use this web site to key in what you think you have installed and see if your speed@RPM’s match.
http://www.grimmjeeper.com/gears.html
 
Spic said:
So just took the cover off and found this,what a fxxkxx, one tooth has snapped off, everything in and around it is really nice and tight, no play at all which I wasn't expecting
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Got a pic? I’m assuming a tooth on the ring gear in the Dana 44 is what you're talking about. You could replace that ring gear pretty painlessly.
 
If you’re already in the diff, the 3.73 ratio has 41 teeth on the ring gear. I guess yours would have 40. :(

I have a Dana 44 Ring gear if you need one;)
 
Squatch said:
It's fairly common. The Rubicon has D44s both front and rear, and the lesser models ran either Dana 44 rear/Dana 30 front, or Dana 35 rear/Dana 30 front. The Dana 44 rear is the preferred axle, though the 3.07 gearing is the least desirable of the ratios, generally speaking.
Click to expand...

So I was looking at this thread

https://wranglertjforum.com/threads...d-what-the-difference-is-with-each-axle.9060/

And it says the Dana 44 came it a minimum of 3.55 gears ? My build sheet says it came with 3.07 rear axle ratio, did some D44s come with 3.07 gears ? The tags have rusted off so I can't see anything to tell me what's what ?
 
JMT said:
If you’re already in the diff, the 3.73 ratio has 41 teeth on the ring gear. I guess yours would have 40. :(

I have a Dana 44 Ring gear if you need one;)
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Will count them now, are D44s known for just randomly losing teeth? If so why ?
 
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Spic said:
Will count them now, are Dana 44 know for just randomly losing teeth? If so why ?
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No, that’s not normal, though I bought a Dana 44 with a tooth broke on the pinion gear, it is extremely rare.
 
mots said:
@JMT I see a 5.38 ratio with 43 teeth. Could that be it?

OP what size tires?
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31 1050's 15s, I put them on about 100 miles ago, before thatnit had standard factory size tyres fitted, Ive only done about 200 miles in it since I've owned it ... it was a little noisy when I drove it home the day I purchased it, but only when coasting or backing off the accelerator
 
Spic said:
31 1050's 15s put them on about 100 miles ago, only done about 200 miles in it since I've owned it ... it was a little noisy when I drove it home the day I purchased it, but only when coasting or backing off the accelerator
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Hmm, ok. I was looking through the ring and pinion sets to see which ones had 43 teeth. Found a 5.38 and a 3.07 ratio with that number of teeth. I think you have the 3.07, but that is odd for a Dana 44.
 
Both ratios seem wrong. My best guess, especially with the broken tooth, is that they are 5.38 and a PO scaled the TJ back down to near stock before selling.

What’s the number of pinion teeth? @Spic
 
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