michael/edge

here we go with another tranny temp question.

i have a 48re. all of a sudden i am running a constant 200 degrees. and it takes very little time to do so.

i dropped the belly pan. the magnet was kinda full of crap. i changed the filter and put new fluid in. back to driving and still hot.

the intercooler line isnt plug. so i am baffled on what to do. cluth fan or where do i start.

also while dinking with the tranny fluid i notice when my truck idles it sounds great but when in gear it goes into a louder knocking noise. any ideas??

Seabiscuit

Hey Michael/edge: I read on another forum that our trucks have a thermostat in the transmission cooler up front. It will allow transmission fluid to bypass the cooler until its up to approximately 150° . Then it opens and the fluid is routed into the cooler. I didn't know it was there, but supposedly they get gunked up with transmission material and it won't open properly and fluid just goes into the bypass, so not much cooling occurs.

You have to clean out the thermostat. Unfortunately you have to put it back in because if you take it out, supposedly fluid doesn't go to the cooler , it will be routed to the bypass all the time.
Now there is another obstruction, there is a ball valve of some sorts that doesn't allow back flow. Supposedly it tries to keep fluid in your torque converter so you can drop it in drive right after starting and you don't have to wait for it to build up pressure idling in neutral. That gets gunked up to and blocks good fluid flow. You can remove it if you let your truck idle neutral after starting up, to get fluid back in the torque converter. That ball restriction is in the return line under the driver side battery supposedly you remove the fender liner to get to it . The guys said they drilled it out. I and worried about that. If I could take it out and use a short piece of hose that would be easier for me. I plan on doing that taking it out.

for the thermostat you need to remove the inter-cooler and loosen the AC condenser and tie it up out of the way, its a job to get to the Transmission cooler.
Here is the link, [URL="http://www.cumminsforum.com/forum/3rd-gen-powertrain/419625-found-my-transmission-overheating-issue-48re-running-hot.html"]overheating-issue-48re
I hope this helps. I wonder if taking the inter-cooler off is hard to do?

I plan on trying both these mods.

michael/edge

thanks for the info. i do notice in the mornings its staying at 150. but on the way home from work when its 90+ degrees thats when it runs hot. i pulled my horse trailer and it really got hot.