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AW4 fluid leaking at drive shaft and it's brown!

Ecomike

NAXJA# 2091
NAXJA Member
Location
MilkyWay Galaxy
OK the 89 XJ I bought for my daughter, and that I did the head gasket job on, which only has 114,000 miles, which has been running fine (between fender benders), is suddenly leaking a little tranny fluid at the rear of the tranny where the drive shaft enters.

THe U-joints feel OK, but I can feel a little slop inside the tranny where the drive shaft enters.

Also, the fluid leaking out is brown!:shiver:

Can the rear shaft seal on the AW4 be replaced with out pulling the transmission?

Any thoughts????
 
Yes, it can. It's not too hard to do, but I haven't had to do it in about ten years, either. Slop could indicate problems that are not going to be resolved by changing the seal though.

Jim www.yuccaman.com
 
OK the 89 XJ I bought for my daughter, and that I did the head gasket job on, which only has 114,000 miles, which has been running fine (between fender benders), is suddenly leaking a little tranny fluid at the rear of the tranny where the drive shaft enters.

THe U-joints feel OK, but I can feel a little slop inside the tranny where the drive shaft enters.

Also, the fluid leaking out is brown!:shiver:

Can the rear shaft seal on the AW4 be replaced with out pulling the transmission?

Any thoughts????

Forgot to mention it is 2WD, no transfer case.

I put in a 12 oz bottle of Trans-X, and let her drive it some tonight, local, <35 mph tonight, in anticipation of draining the fluid very soon. It was pretty close to full still, about 1" over the full line after adding just 12 oz, so I will drain some when she gets back, to get back to the full mark at the top of cross hatch area on the dip stick.

I am sure it just started leaking.

I do know the prior owner was running it at 230 F, before I replaced the radiator, thermostat and head gasket right away, so I am hoping I caught the burned fluid early, but I have not done an AW4 rear seal yet.

Hoping it is an external R & R part?
 
Yes, it can. It's not too hard to do, but I haven't had to do it in about ten years, either. Slop could indicate problems that are not going to be resolved by changing the seal though.

Jim www.yuccaman.com


So the $XXXXX question is how much slop is normal there. I'd say this one has about 1/16" of side to side play at the rear end of the tranny.

Another question. The ATSG service manual for the AW4 says to check the fluid level while in neutral, but the dipstick says to check it while in park?

Which is correct?

I see from the manual that there seems to be a bushing behind the seal.

OS! I just read this. On 2WD models measure the ID of the bushing. It should be 38.09 mm or less. If it is larger than the spec, then replace the housing assembly!

:( Ouch. Wonder what one of those costs.
 
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Well the 15 oz of Trans-X additive seems to have stopped the leak for now.

No other problems yet.

I discovered that my 87 Trans- dip stick also says to check fluid while hot in Park, not while in neutral. And the 89 dip stick has 2 sides, one for reading fluid level in Park while cold, the other for reading fluid level while hot in park!
 
Park and neutral should be interchangeable, as Park is neutral, but jammed with the Parking Pawl. I believe the rear seal on the tranny should just pop out, like an axle seal. Buy one first, and see if it resembles an axle seal.
 
Park and neutral should be interchangeable, as Park is neutral, but jammed with the Parking Pawl. I believe the rear seal on the tranny should just pop out, like an axle seal. Buy one first, and see if it resembles an axle seal.

Not sure about the AW4, but some, if not all automatics disconnect the hydraulic pump in park, and engage it in drive, which changes the fluid level reading on the dip stick between park and neutral, difference being the clutch packs are not engaged in neutral.
 
Was the fender bender in the front ? I have seen a few that have been hit in the front pushing the radiator into the engine . When the engine gets hit it pushes the trans back and forth very quickly and causes the output seal to be damaged . I have seen that on a few dif cars and trucks . This may not be the case with your Jeep , just thought I would throw it out there .
 
You dont have to remove the pan to change the fluid . There is a drain plug on the back of the pan .

Really! Thanks, I was not aware it had one.

I got about 3 quarts sucked out through the dip stick already.

Hers was not hit quite that hard. Although the radiator made just enough contact with the fan/clutch to make the Rad toast. The clutch and water pump bearing were still OK so the force stopped right there.

I rechecked the fluid in both AW4's and they are both more of an orange color, not burnt brown yet, and not new pink colored. I am going to start doing partial fluid changes as time permits to slowly get the old stuff out and the new fluid in so as to not loosen a bunch of stuff (varnish if there is any) all at once.
 
Update:

I did 3, 3 quart transfusions, drained 3 quarts & added 3 quarts, 3 times, each a week apart. Used DEX III autozone branded T-fluid. That was about 5-6 months ago. The leak has pretty much stopped since then, and has not returned, or at least dropped by a good 98%. No wet spots on the driveway anymore, for about 6 months now.
 
I'm wanting to think there should be a bushing inside the tailcone housing as well, and it may want replacing. You should be able to remove the tailcone without having to remove the entire transmission - just take it off, replace the bushing and seal, and replace.

Make sure the driveshaft slipyoke is nice and clean (dry crocus or emery, then wet to polish,) and lubricate the slip slightly before you reinstall it.

It's also possible for some of the "old" transmission fluid to collect back there and look burned, or for it to be contaminated with seal/bushing bits. Change three quarts of fluid is a little less than half - as I recall, a "total fill" on the AW4 (torque converter and all) is eight quarts.
 
Yup. I recall replacing that bushing sleeve a while back. It's three or 4 bolts to pull the talicone adapter and then you need to rig up something to tap or press the sleeve out.
 
Yup. I recall replacing that bushing sleeve a while back. It's three or 4 bolts to pull the talicone adapter and then you need to rig up something to tap or press the sleeve out.

Yah. Most 2WD autos (and manuals, for that matter) have the bushing in there to help support the slip yoke - and it's not pressed in there too tightly. About a .0005" interference fit, I think. I've always been able to tap them out with a drift and a hammer, just make sure you have a nice square end on the drift. Install with a bearing/seal driver.
 
No doubt I will eventually need to do that. What surprised me is that it went from an obvious puddle leak under that area (the leak was significant and obvious), to pretty much no leak with just 3 sets of 3 quart transfusions.

The tranny was also starting to shift odd. Can't help but wonder if the new fluid had a significant seal swelling effect, and a higher viscosity than the worn brown fluid which was headed toward the burnt category.

It has probably been about 5 months and 5000 plus miles since the last fluid swap, and no leaks or odd shifting since.
 
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