My 1995 Dodge Ram 12 valve Cummins 4wd automatic transmission no longer will go over 40 mph. I am hoping to get some ideas ASAP as it is my daily driver/work truck. i was towing a car earlier in the morning for about a hour round trip and it pulled perfectly fine and I dropped that one and drove the trailer empty for about 20 mins stopped for about a half hour and then starting going again and soon as I got on the highway it would just not go over 40 and just revved up to 2500rpms. The truck has 240k on it and i bought the truck at 227 and the previous owner said transmission was rebuilt at 200k. I am not in the position to buy another truck and i need this back on the road ASAP any help is greatly appreciated .

 

I guess I'd pull the pan and see what it looks like. If it still has the check valve in the cooler line to the radiator, it may have plugged and overheated your transmission. I'll see if I have a picture.

 

Thank you for the response. I did not get the trans overheating light come on so i dont think it did. When I pull the pan what am i looking for?

 

The line with the hose clamps is in place of the factory one with the check valve in it. If the trucks sits a few days I have to put it in neutral so oil flows through the tranny before I put it in gear. Our transmissions don't flow in park unless you have a Sonnax Sure Cure kit installed. ( You need to check fluid level in neutral on a stock tranny because of this.)

 

mine does have the stock tranny lines, should i do what was done there?

 

If there is a lot of metal filings in the pan you have junk. There is normally some fine residue in the pan from normal operation. You'll know the difference. There is a DIY on adjusting the bands. I would change the filter and adjust the bands if the pan isn't full of trash. Dodge tranny's take ATF +4 Transmission oil. It honestly sounds like you had a failure, but maybe not.

 

https://dodgeforum.com/forum/2nd-gen...46rh-46re.html

You need to diagnose the problem you have first though. What is yours doing now? Does it move in all the gears? Everything but OD?

 

yes moves perfectly fine in gears perfectly fine and sounds healthy also expect it will not go over 40 mph and just revs higher if i tried to

 

https://dodgeforum.com/forum/2nd-gen...agnostics.html

Trans mission diagnostic thread. You should have an RH transmission I think the RE started in 96. I can't remember if the overdrive is bolted on the rear of the tranny and can be fixed without removing the whole thing. I read about this stuff quite awhile ago but don't remember. I know the answers are here somewhere. I wish one of the guys more familiar with these would log on and help you.

Sounds like the OD clutch failed or there might be a one way roller that failed. I can't remember what usually fails in the OD. If you had the RE there are solenoids that fail.

 

https://dodgeforum.com/forum/dodge-r...djustment.html

This should be the band adjustments. In that diagnostic thread it looked like the OD is bolted on the back of the transmission. Someone that knows more than me would have to tell you if it's possible to repair the OD unit. If it failed it might have contaminated the rest of the transmission. Hey You is usually on first thing in the morning, he probably knows or can point you to the right thread to read. Sorry I can't help more.