Automatic transmission overheating

[Heimir]

I have a ´91 Explorer sport.

In hot weather driving offroad it has happened tvice that i loose transmission fluid.
It comes out of the transmission somewhere, of course really hot and thin.

One time i was climbing a mountain road and didnt notice until i stopped that almost all of the fluid was gone and it wouldnt shift.

when i refilled the transmission the problem was fixed and it didnt seem like it had damaged the transmission.
However it takes a little long to get into gear after i move the lever, but it has been that way since i bought it.

Anybody have a solution for this, an extra cooling element or a larger one?
it would be great to hear from someone who had this problem.

Regards
Heimir

 

[stang99x]

I have the exact same problem with my blown navigator. Derale makes a tranny cooler with fan that will aid you in finding a solution.

 

[Glacier991]

Heat in a transmission is either a product of slippage in the transmission clutches and/or bands (some of this is normal) and also can occur in the torque convertor prior to lockup. When it overheats, you have a condition which is creating excessive heat. More often than not it is related to slipping cl;utches and bands, often occasioned by low pressure not locking them up appropriately.

You would be well advised to have your bands adjusted and consider a rebuild of the valve body and putting in a "shift correction kit" and adding the Sonnax upgraded boost valve. At the same time you would replace the seal on the low reverse servo, which *might* eliminate or improve your delay into reverse and first gear.

An external cooler is always a good idea.

I am moving this to the transmission forum where you will get better exposure and more advice.

 

[BrooklynBay]

You could be having two different leaks. The first one is that you could be leaking fluid out of the vent in the rear of the case. Off roading throws the vehicle at awkward positions. The next thing is that your front seal in the bell housing could be leaking fluid when it runs hot due to low coolant in the radiator. If you would be leaking fluid all of the time, then I would say to check your vacuum hose going to the modulator. The modulator's diaphragm could have blown, and might be causing problems with your shifts.

 

[BrooklynBay]

Here is a link to an article on WWW.ATRA.Com which addresses the low coolant condition that causes the front seal to blow out when it is hot: Dead Link Removed

 

[Glacier991]

Much as I hate to say this, if you are a serious offraoder running oversize tires... the 4.0 with an A4LD is just not up to the task, even with a cooler etc. Occasional use with stock tires, yes, but heavyduty stuff and oversize tires, no.

 

[Heimir]

Thanks alot for the quick responses, they help alot.

Regards
Heimir.

 

[BrooklynBay]

This article talks about the front seal blowing out in a 91 Explorer: http://autorepair.about.com/library/a/1d/bl593d.htm