AW4 woes - have searched

[gcurtis]

Here are the symptoms:

Over time I'd noticed my pep had slowed considerably.

Tranny starts over heating, causing blowback up the dipstick tube. Replaced the fluid immediately, added a trans cooler and temp gauge. Had tranny flushed and did the screen as well (not power flushed but fluid pulled from the converter and pan drained).

Fast forward 60 days. I'm on a trip to the Sierras and driving up a long hill. Trans is hitting 230* and won't go past 35 mph at 3100 rpm... obviously slipping. On any small hill the tranny will start to get hot and rapidly even before the trip.

Tranny has 87,000 miles on it, fluid changed right when I bought it at 56,000. All I'm reading is the tranny is bullet proof but did mine take a bullet instead? Am I overlooking the obvious?

[MAP]

Here are the symptoms:

Over time I'd noticed my pep had slowed considerably.

Tranny starts over heating, causing blowback up the dipstick tube. Replaced the fluid immediately, added a trans cooler and temp gauge. Had tranny flushed and did the screen as well (not power flushed but fluid pulled from the converter and pan drained).

Fast forward 60 days. I'm on a trip to the Sierras and driving up a long hill. Trans is hitting 230* and won't go past 35 mph at 3100 rpm... obviously slipping. On any small hill the tranny will start to get hot and rapidly even before the trip.

Tranny has 87,000 miles on it, fluid changed right when I bought it at 56,000. All I'm reading is the tranny is bullet proof but did mine take a bullet instead? Am I overlooking the obvious?

What year XJ do you have?
Does the fluid turn dark in color?
Does the transmission downshift when going up hills or does it stay in the higher gear?(and bog down the engine)

How's the engine doing? Any problems?

[gcurtis]

What year XJ do you have? ---- '99
Does the fluid turn dark in color? ---- No, fluid stays clean (but is brand new)
Does the transmission downshift when going up hills or does it stay in the higher gear?(and bog down the engine) ---- It down shifts.

How's the engine doing? Any problems?[/QUOTE]---- Motor is fine and solid.


Also, trans had that "clutch burn" stink after climbing that hill in the Sierras.

[Yucca-Man]

...and what tires and gears are you running? Stock is 3.55 but larger than normal tires will help heat things up considerably.

[BrettM]

synthetic fluid?

rumor has it that the AW4 doesn't like synthetics and that they are too "slippery" for it.

[mgreen84]

I had the same problem with my 98 a few years ago, running 32's with stock gears and towing a trailer overheated the tranny even with cooler w/ fan. Once I broke the tranny down to rebuild I found some of the teeth in the Torque converter had sheared off. The intermediate clutches looked like they had been sand-blasted, it all made since (clutches and all) but still can't figure out the teeth shearing off the converter.

[gcurtis]

DEX 3 in the tranny, not synthetic.

Tires are 31's on stock 3:55's. Would that cause slipping of the tranny? Seems like the tranny should be able to hold a little better than 31's...

No towing at any time in this vehicle.

Well, it looks like I might have one of the "unbullet proof" ones. I guess it might be time for a rebuild. Chit.

[summitlt]

I have a AW4 out of a 1998 if you need a replacement.

[gcurtis]

I'd love it but you are on the other side of the US of A. Thanks for the offer, though. :)

[Mercenary]

What kind of shape is your tranny cooler in?

[jeepsrock]

*Change the TPS sensor, whihc has a large effect on the trannys shifting.
*Change fluid to regular mercon/dexron not synthetic fluid.
*Make sure fluid lines arent pinched anywhere and that they are getting warm near the front end

pete.

[gcurtis]

What kind of shape is your tranny cooler in?

Brand new radiator plus a B&M aux cooler.

[gcurtis]

*Change the TPS sensor, whihc has a large effect on the trannys shifting.
*Change fluid to regular mercon/dexron not synthetic fluid.
*Make sure fluid lines arent pinched anywhere and that they are getting warm near the front end

pete.

The TPS I may try next.

I'm already running Dex

Fluid lines are "clean" and not pinched.

My primary concern at this point is slipping of the tranny, which seems to be the tranny itself.

[gcurtis]

Well, it looks to be the trans is bad at 86,000 miles.

Talked to the guys at Mogi Transmissions (they build race stuff and know what they are doing) and they, too, were perplexed that an AW4 was crapping out so early. They had me check codes (there were none), check the cat by drilling into the pipe before the cat and checking pressure with a guage and then rechecking the fluid smell after trying to repeat the slippage.

Trans fluid, even though it has less than 1000 miles on it, smells burnt.

I guess I'm taking it to Mogi for a rebuild, beef up and custom valving...