when i bought this car(91) the previous owner had installed a newer auto tranny. when i talked to him about it he told me that i had to replace the tranny cooler. my question is, what causes the tranny to over heat even when there's a tranny cooler there to help? how can i prevent this from happening? cause when the tranny over heats it stays in what ever gear its on and it feels like there's no power to the wheels what so ever.

 

I had the same problem except mine never had shift problems, just overheat. I replaced the water pump, radiator, and installed a trans cooler in place of A/C condenser, and a 180* thermo. A bit of overkill, I probably should have stayed with just the new radiator. I also put an electric fan with on/off thermostat. Now it`s running too cool. I had given this car to my son and now he says it won`t shift `til it warms up. What needs to happen now is the original range thermostat installed and maybe bypass the external cooler, especially with colder weather coming up. Later, he`ll probably want to replace the A/C condenser for next summer. Help any??

 

Oh, I also replaced the trans filter and fluid, worked fine here but my son is in Maryland and the trip showed it all up. It barely came out of the cold bracket on the gauge...

 

hmmm so probably just replacing the tranny cooler would do then?

 

You do know that the "tranny cooler" (the potential for jokes here is practically endless) is integral with the radiator, right?

 

O_o to be honest no i didnt.

 

oh yeah and what about the filter that jb 5365 mentioned?

 

As said, the tranny cooler is part of the rad. Did the PO add an external cooler to the system? Either way, you may want to flush (don't know if these can be backflushed) the cooler and lines to make sure the fluid flows freely.

 

I dont know what auto trans is in our cars never seen one in person or have my book on me but have worked in a trans shop for a while and usually if your temps are up on trans. it usually is a blocked line, abuse, or insufficient cooling. If you have an external cooler and is overheating the damage is probably done. Drop the pan and break the filter apart and look for metal inside. Is the fluid burnt. Is there a trans temp gauge on autos or a dummy light. How do you know its overheating.

 

And if you have problems a good flush is a fantastic way of wiping out the trans completely. The nasty *** old fluid acts as a friction modifyer on the beat up old clutches. if its a clogged cooler flush cooler only. take to trans shop and have them hot flush it. a regular trans flush most likely wont clean cooler out anyway. And external coolers are the way to go in any hard driving condition. A cheap 12 by 6 cooler from a parts store is only like 30 bucks.

 

hmmm well i dont have time to check right now. i will in the morning though so i'll post up then about it all. thanks.