240ROCKER wrote:Well guys I found out something interesting about having your automatic transmission rebuilt. Apparently, when you opt to have your automatic transmission rebuilt, this does not include rebuilding the "valve body" which is the brain of the transmission. Several people have posted on here and on other places on the internet who decided to rebuild their transmissions only to find out that they still had the shift problem. What a bummer to know that you spent all that money for a rebuild and it didn't actually fix the problem.
The valve body has all sorts of control valves and springs and is a very expensive part to replace, which is why most tranny shops don't rebuild or replace these.
I have learned that more than likely I have a stuck control valve in the valve body and the reason that I normally don't have a problem in colder weather (50° or lower) is because there is more pressure being built up in the valve body to compensate for the colder temps. and when it's warmer weather, the pressure isn't as high and therefore one of the control valves that pertains to the 1st to 2nd shift is getting stuck. I was told that an additive called "Transmedic" might unstick this valve. It will take about two to three weeks to really get into the system, but that it might keep that control valve from sticking.
What are your thoughts on this?
Modified by 240ROCKER at 1:03 PM 3/1/2005
i can vouche for that. i rebuilt my A/T about 6 months ago. it was slippin, shifting slow. then finally the torque converter went out. so i did the whole nine yards. i seen the valve body, made sure it was operating by blowing pressure in it. it shows u how to check in the rebuilt kit manual. basically all i changed was the clutches and rings and what not and of course the torque convertor. so now it drives a LOT better, but it still shifts slow. like the valves are working but not fast enough. this must be a issue with these cars for sure. while doing this, i also found out you can use pathfinder transmissions. so if any of you guys ever just want to swap to a used one, you can use the pathfinder as well. but if you rebuild a pathfinder tranny, make sure you get the parts for the pathfinder, not the 240. the 240 clutches arent as thick. if u put them in a pathfinder tranny, you will have serious shifting probs. and dont ask me how to tell the difference if youre not sure. i found out when mine was completely apart that it has the pathfinder tranny in it by measuring certain internal parts and comparing them to a chart. then i wrote on the tranny for any future reasons, that its a pathfinder tranny. good to know these things.