truck has been fine for the last couple of month of dealing with the auto. So today I take a dry run out with the horse trailer to bring it home and make sure the trailer fits at the new property we are going to be building a house at etc. Hook trailer up tow it home about 6 miles from home notice the trans temp is warming up rather quick from 150 to 195 but stays there. Then slow through town and 215 225 245 265 275 (tripped the dash light too) and stays right around that themp till I turn off onto a side road. Put into 4 low to see if it's the converter not locking up but temp doesn't really change then drive it to property starts to cool but stays around 225 unhook drive home and it runs right down to 138 and stays. So what could be causing this. I have a aftermarket converter, billet input shaft complete rebuild on the trans with a deep pan and run the lock up switch at my dash. I know the switch works I tried it when hitting the highway from the property and it stays locked from 2nd to 3rd etc. When I slow way down and leave the switch on it shakes like you let the clutch out at too slow of speed. I am lost... ready for a stick of dynomite and start over...

Well, def a cooling issue i would say. The only thing i can think of is the stupid check valve in the tranny cooling system. I don't know if its in the cooler in the front of the truck or if its the heat exchanger can next to the engine under the turbo. I thought i read one of the other members say it was in the heat exchanger. Hopefully one of the other members will join in on this one.

the trans cooler was just done in febuary this year. I put on a big cooler that the local tranny guy I know uses and bypassed the heat exchanger. I have had issues with the tranny now and then. Back in oct I was towing a small horse trailer with 30 bailes of had and the truck did same thing so I was told that some people have issues with the exchanger so I bypassed that and seemed fine. So I hooked the trailer back up and temps stayed better but then started to climb in the 220's. I pulled the trans cooler and it was clogged so I changed that truck has been fine since but no real towing till today. A few weeks ago I did tow the 102 wide 16' enclosed trailer home with no issues. Could I have a week pump or issue in the converter? no matter what I have changed it still gets hot.

When I did the repair I flushed the system while running and got rid of all the old smelly fluid. My dad added fluid and I watched it as it filled up the 5 gal bucket till nice clean red color and had the neighbor kill the motor when it was done. the filter was changed too. used atf 4 on it
I checked the fluid before we left. I had run the truck around before we left and figured a good time to check it. it was good. It's almost like a week pump or something


so I have no check ball valve.

truck would also do the same thing when driving off road at lower speeds. but I started using 4lo so it would lock up at lower speeds and never had a problem offroad since but was never off road for long

Make sure the coolers are not dirt or greasy...

Make sure your got enough fluid in the trans and of the right type!

No kink hoses or tubing...

used mopar atf4 in it it's full lines are good. was just serviced in oct with less than 5k on it all.

Who built the transmission? How tight is your converter? What valvebody are you running? and what kind of line pressure are you seeing? I would start looking at those as well. You may be on to something with the pump though. I'm not sure what the pressure is supposed to be in the cooling system or the flow, but if you could check that and find specs on it, that may help you out too.
Sean

In the last 24 hours have talked to a few people and have pretty much all stated it's my valve body. My valve body is stock with just a lil line pressure increase. Turns out my supplier of parts was off on the stock valve body being able to handle it all. So thats my next step. I tested flow of my system and got 2 qts in 24 seconds roughly. Did a complete system flush today so that way when new valve body is installed there is no real mess just change add fluid and run. Thanks for the help.

as for a vlave body who should I go with. hts suncoast etc etc etc

Yeah, that really sounds like its your problem. Being able to keep line pressure up on the clutch packs should help to reduce heat quite a bit, especially when towing, because you are putting more load on them. Honestly, I think they will all be pretty comparable in quality and should be similar in price. Plus you can have it tuned however you want it, firm shifts, soft shifts etc... I would go with who you feel has the best customer service or seems the most knowledgeable on the phone. I'm happy with my DTT stuff in my trans.
Sean

I appreciate it

Dave Goerend is a nice guy to talk and deal with and lots of guys like his VB.