hey guys. so i recently drove from knoxville to nashville. just under 200 miles. (1997 xj, auto. stock gears and 33s. it has factory trans cooler) I pushed it way to hard which was stupid. i was crusing at like 85 mph/ before too long fluid was coming out of the vent on top of the tranny. i got knoxville fine where i had it looked at. fluid was very low so had it topped off with atf 4 plus. im driving 1200 to vermont in couple days where im moving to. Im wondering if i drive at normal 65 mph and reall take it easy if it will be ok or will heat up again? Is there anything i can add to the fluid to help it keep cool? at least until i can get to vermont?

 

and i just read that atf 4 is not best for the aw4. once i get to knoxville i will my guy there drain, replace screen and gasket and refill with proper stuff. does this sound ok to do? Is it bad to change the fluid that quick?

 

You really don't need to replace the screen as long as the fluid is reasonably clean. Just remove the drain plug, drain and refill.
The trans cooler lines- make sure there are no kinks. Coolant temp is normal? TCC lockup is working when you are cruising above 45 MPH?

 

I would drain and refill with Dex/Merc 2 or 3 times (with a short drive in between) to try and flush out as much of the ATF-4 as possible. Walmart sells Supertech Mult-vehicle ATF that is DEX/Merc compatible for cheap. Make sure not to over fill the transmission. I would also make sure that your transmission breather vent, located near the transmission dipstick attached to the firewall is not stuck. There are two vents near this location; one is for the transfer case and the white one (probably discolored by now) deeper down is for the transmission. If this is stuck closed it will not allow the transmission to breathe and build excessive pressure causing heat and transmission fluid to be expelled. Whenever you have a chance I would install a good quality transmission cooler as the AW4s are known to run hot.... hope this helps

 

 

An auxiliary tranny cooler mounted inline with and after the factory cooler should help some to dissipate the extra heat generated by the extra load of big tires and high speeds. Search tranny cooler.

 

what cooler is everybody using for our Xj's?
I am thinking about buying a cooler and inline filter as well
Where is the Best place to mount it?

 

 

Transmission cooler only if really necessary.
You'll notice in the picture above there is so much crap adding heat to the air, it's no wonder that thing probably runs hotter than ****. Unless you plan on "crusing at 85" (ha ha) transmission should be just fine.

 

I put on a Long Tru-Cool 4544. Rated for 22k gvw. This seems like it would be over kill, but it's really not. My pan temp would get up to 230° with the factory cooler. Max now is about 180°.

 

True, you'll just need to change the fluid more often. However, with a well maintained system, I've never had a problem with the 4544 cooler.

 

I see the problem for sure as I had the same one for a short while upgrading to a 33x12:50 tire and not doing the gears at the same time. I went to a large cooler and it did nothing to help the trans from up/down shifting creating the heat.


Your running a 33" tire with stock 3.55 gears when you should have a 4.56 gear. The trans is up/down shifting all the time even on level ground causing the heat issues. A larger cooler won't help till you cure the problem re-gearing to 4.56 for that tire.


I guarantee you that it will overheat again and very possibly fail completely on a long trip with those gears/tires

 

Hope the drive is uneventful! Make sure to drain, refill and test drive before setting off. Vermont is pretty awesome, not that I'm biased or anything..

 

Very good point Fred.

 

Actually the cooler didn't change the engine or engine bay temps even with the AC on. But it did make a difference to the trans when hauling a loaded to the hilt trailer on an extremely hot day. Sure,I don't need it most of the time but it only takes one time to fry a tranny.