aw4 took a puke!

cher96 said:

I use an OTA External Transmission Cooler and a 3 Core HD All Metal Radiator, Hi Flow Water Pump, Hi Flow Thermostat Housing & Thermostat.

It is better to bypass the Radiator and go with a 30,000 to 40,000 GVW Transmission Cooler so that there is better flow and cooling of Fluid especially if your XJ is Used for Crawling or Towing. IMHO I used to have to change out my Fluid every 6 months because it was burnt. It's Extremely hot in Tampa, FL

I Mounted mine Like GoJeep has his: http://www.go.jeep-xj.info/HowtoAutoCooler.htm

Some come with a External Thermal Bypass for Cold Climates others Not. If you live in a Cool Climate just Buy a Cooler with the Bypass. IMHO

Here is info from: http://www.makcotransmissionparts.com/cooler-info.html

The most often asked question is should I bypass the radiator cooler when I install a auxillary cooler.
Most cooler manufactures and automobile manufactures information we have read, recommends installing the coolers In-Series with the factory radiator cooler for maxium cooling efficiency.
So unless the manufactures who have spent 1000's of hours testing different installations are wrong, the suggested cooler installation is in-series......
Transmission > Radiator cooler > Auxillary cooler > then Back to the transmission.
If you must bypass the radiator because the cooler tube is leaking or for other reasons, be sure to increase the size cooler you install by 1 to 2 sizes. I Bypassed the Radiator, I Live in Florida, and I go Offroad so that is why I went with the 40,000 GWV Cooler (.

Pickup Trucks, SUV's
Towing up to 7,500 lbs.
# Coolers with GVW ratings of 22,000 to 26,000 lbs.

HD Trucks, Motor homes
Towing up to 10,000 lbs.
# Coolers with GVW ratings of 22,000 to 30,000 lbs.

Super Duty trucks
Large Motor homes
# Coolers with GVW ratings of 28,000 lbs. and UP

* Millions of automatic transmissions fail every year from overheating. If you tow a boat, trailer, camper or drive in Stop & Go traffic you risk overheating your transmission fluid.When your transmission fluid reaches 200o it starts breaking down.
* Transmission coolers help extend the life of your transmission fluid and can prevent transmission failure from overheating.
* At 240 degrees varnishes form and transmission life expectancy is cut in half.
* At 260 degrees the transmissions internal seals and rubber parts harden and major damage starts.
* Above 295 degrees you transmission start slipping, clutches burn out and carbon forms.
* With each 20 degrees drop in operating temperature, your fluid and equipment life doubles.
* Installing a cooler before damage starts and by reducing the transmission fluid temperature by as much as 60o can greatly extend the life of your transmission.
* Installing a transmission cooler can prevent transmission burnout.

Tru-Cool 4739 MAX with Thermal Bypass Valve TC-4739
For Vehicles with 3/8" Transmission Lines
YOUR COST: $143.00

Source: http://www.dieselsite.com/index.asp?PageAction=VIEWPROD&ProdID=205

The Thermostat is set at 90 degrees according to Tech Support.

http://www.transmissioncoolers.us/Merchant2/merchant.mvc?Screen=CTGY&Category_Code=trucool-MAX-cooler


# 4739 Tru-Cool MAX transmission cooler with external thermal bypass
The Thermostat is set at 90 degrees according to Tech Support.

Tru-Cool # LPD4739, 40,000 GVW rating, 45,000 BTU rating
8 1/2 x 22 3/4 x 1 1/4 inch
3/8 inverter flare (fittings are included for thread to hose barbs) Includes external thermal bypass for cold climates!

$140.00


# 47391 Tru-Cool MAX transmission cooler *No external cold weather thermal bypass

# LPD47391 Tru-Cool 40,000 GVW rating, 45,000 BTU rating
8 1/2 x 22 3/4 x 1 1/4 with 3/8 inverter flare (fittings are included for thread to hose barbs)
*No external thermal bypass*Great choice for southern states where the winters are mild.

$118.00

# 4921-1 Tru-Cool MAX transmission cooler (Medium Max)

3/8" hose barbs on side of cooler.
Size 6 x 23 x 3/4 inch
WITHOUT external thermal bypass!
12 plates, 30,000 GVW / 34,000 BTU ratings

$92.00

# OTA Cooler

Part No. 4739
Price: $129.95

40,000# GVW rating transmission oil cooler. 8 1⁄2 x 22 3⁄4 x 1 1⁄4 193 sq. in. cooling area Reduces heat related failures during severe duty conditions such as towing or exhaust brake usage. BTU Rating 45,000

http://www.suncoastconverters.com/ford/e4od/forde4odcoolers.html

Hope this will help someone.

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joe_peters said:

Sometimes when the AW4 gets hot enough it will vomit out of the dipstick tube.

Some posters recommend going to a higher quality (synthetic?) fluid is the fix.

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jeepcomj said:

NONONONONONONONONO


never ever put synthetic in an aw4 transmission. especially a used one. the brass/graphite in the clutch packs is not designed for synthetic lubricant. it WILL detonate if you put synth in a used tranny.


some people switch to synthetic off the show room floor and never have any issues. I wouldn't ever do it, but they have.

I can just tell everyone here that the only time I've had issues with an aw4 was when I put synthetic in it to test the theory. ended up cooking the tranny so bad that I lost all gears unless going downhill (getting it up-hill was very tiring:doh. use dexron atf +3 or +4


as far as your specific tranny, you overheated it, cooked it, boiled out the fluid, and probably burnt the fluid that's left in it. give it a trans. and cooling line flush along with new gasket and filter, and install a large aftermarket tranny cooler and you should be good to go.

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