smtippin

Just found an 87 with the Dana 44. The seller wants a whopping $125 and he'll pull it from the donor vehicle for me. My question though is what axle is up front. I wasn't able to get a great look at it, but it did look different than my 96's D30.

The seller was telling me also that the gear ratio between my current set up and the D44 is different (obviously) and that would cause my transfer case to bind because the front axle would spin at a different rate than my rear. This is way beyond my auto-knowledge. When I swap to a Dana 44, do I need the front axle from the donor too? What acle/gear ratio are these? What don't I understand?

s

BuckB91XJ

The 87 XJs that came with rear D44s still have D30s up front.

winston427

The D44 in the 87-89 models was for some XJs with the towing package. It should be geared 3.73

That a great deal for it to.

BuckB91XJ

The 87 XJ I got my D44 from was a prior police rig. It was geared at 3.55 and open. No LSD of any kind.

BLKXJ 96

I would keep your front axle from your 96 as it is a High pinion and the housing is stronger than the D30 from the 87 with a vacume disconnect axle, and the 96 axle is probably running stronger U-Joints (if the 96 has ABS). Just match the gear ratios front to back.

winston427

Even without ABS, all XJs from 95 up had the larger 297 u-joint.

ktmracer419

false

winston427

If the seller is telling him that the gear ratio is different than what he is running in his 96, then that would lead me to believe it is 3.73. Since that was used for some XJs with the towing package. I have double checked my research material and see that he has a manual trans. So he must have 3.07s and the D44 is 3.55.

whowey

Never use the terms 'must or always' when dealing with AMC-era Jeeps. AMC didn't stick people with packages and not let them change things on them. When you bought a Jeep you could specify almost every detail and option about it. When you got a towing package, 3.73 gears were more common with the auto tranny. But you could have gotten 3.55's. Just like with a manual tranny and the towing package, 3.55's were more common, but it could have been any available gear ratio.

And if it was a non-North America rig, the front axle could have been a D-44. But if it wasn't it was a Hi-pinion Dana 30, vacuum disco would depend on transfer case.

COSXJFAN

My 87 doesn't have a CAD on the D30??

Not nessacarilly, mine was 3.55. It may very well be the same ratio that you have in your current D30.

Quoted for truth, you never know what "surprises" your Jeep may have!! LOL!!

winston427

Thats what I love about this website. Even with as much research as I have done to learn about how to work on my XJ, and the pros and cons of each model years options, I still have much to learn.

smtippin

Wow. I've learned a ton from this thread so far. Tell me if my understanding is accurate:

1. Front axle's on the 87 XJ's with towing package (D44 rear) primarily came with D30's, although there is an outside chance that it is a non-N American XJ with a D44 front too. Anyone have a pic of this front axle for confirmation?

2. If the front Axle on the donor rig is a D30, I should stay with mine because even though it is non-ABS it will have the larger 297 u-joint.

3. Dana 44 rear Axles will have either a 3.73 or 3.55 gear ratio. 3.73 being more common. Which gear ratio is 'better' and why?

3. I think Winston 427 said my rear axle is geared at 3.07 (96 4.0 with the AX-15). Is that true/high probability of being true? How can I determine what the gear ratio on my D35 is without pulling the diff cover?

4. I was told that the front axle's gear ratio needs to be lower so the wheels spin faster. Is this true? If so, does that mean that stepping up from the D35 to D44 rear axle would not be hazardous to the transfer case since the D44 is either a 3.55 or 3.73?
Thanks for the help. I've got more reading to do. I really appreciate learning this stuff.

s

CrazyTJ01

No that is FALSE. You need to have the same gear ratio front and back. Same size (diameter) tires front and back also.

whowey

1. Yes... but sorry no pics... The center section will look almost identical to a D-44 rear...

2. Yes... the 297x u-joints are preferable as the larger caps and crosses offer a stronger joint.

3. AMC allowed you to order any of the 5 gear ratios at anytime. But if the original owner did not specify a different one, 3.55 was the normal in an automatic 6-cylinder Jeep. 3.73 was more common in the automatic,6-cylinder Jeep with the towing package. 3.31 was the 6th gear ratio available in Cherokees, but supposedly only in vehicles with California Emissions.

3.(the number so nice you used it twice) Normal gearing for a 6-cyl, 5-spd was 3.07. But the others were available by option. Originally there was a tag on the rear differential that had the info. If the tag is gone.. there are two ways. Pop the cover and count teeth. Or mark the d-shaft and the axle shaft. Turn the d-shaft and count the number of turns to make one full turn of the axle shaft. That will give you the ratio.


4. No... The difference can only be 9% or less. None of the available gear ratios are less than 9% apart, so you need to have the gearing the same.

JeepCoMJ

where do you get your information from?

87 is still high pinion.

disconnect housings are STRONGER than non-disconnect, and the pass. side UCA mount won't break off like your flimsy non-disco will.

OP, get the front and rear axles, then do some research and you can find the seal number you need to convert it to a one piece axleshaft on the pass. side by using your 96 pass. side axleshaft. switch both axleshafts from the 96 into it.