I put gauges on the accumulator and reverse ports. The accumulator pressure on startup is 95psi and after about 1 min it drops to 10. The reverse pressure starts at about 160 psi and drops to about 30. Or maybe just wishful thinking.

Any idea where to look? It seems like the pressure holds up longer than it should if there was a massive leak somewhere.


I have a 1997 Dodge 2wd diesel auto. It has a aftermarket torque converter, modified valve body and has the resistor. I was just on a 2000 mile trip in the eastern snowstorm. Transmission worked great for the first half. Drove all day at 45 to 50 mph so I had it locked out of overdrive and worked fine.

First indication of bad things to come was when I was in small town going slowly and I could feel the transmission holding back. At first I though one of the trailer wheel had locked up. Stopped, checked fluid, etc and everything was normal. It did it two or three times at low speed but when I went faster everything was fine. Drove another two hours and everything was fine. Finally drove out of snow and went to overdrive and transmission slipped and then stopped pulling altogether. Coasted to a stop and tried all gears and no movement. Great, I thought I broke another input shaft.

Called for a tow. Started the truck 5 minutes later and transmission seemed fine. Did a brake stand it it seemed to pull good. Decided I didn't need a tow and started to pull into traffic. Transmission slipped and then went to absolutely nothing again. Got a tow of truck and trailer to motel.

My brother drove down with his truck and another trailer to haul it home. Started it the next morning in 0 degree weather and transmission pulled and drove up on tiltbed trailer. While we were balancing trailer transmission quits pulling anything again. Not even a wiggle. Shut it off and five minutes later it pulls again.

So the question is is this an electrical problem or mechanical problem. I haven't put any gauges on it yet. It seems to pull real good for a minute or so and then it doesn't pull anything, like it is in neutral.

 

These pressure measurements are in gear right? Something's wrong internally, what I don't know exactly, but those pressures are not right. 160 psi in reverse at the rear servo is on the low side. You probably also smoked the clutches with all the slipping so a overhaul is probably the next step.

 

Replace the oil pump. Before you do that check the band adjustments. If there has been some binding there will be a lot of clutch material in the pan.

 

I have to ask this, I didn't before. Did you check the fluid level with the trans in neutral? Sorry I have to ask, I didn't see anything about it in your post. I reread it and it sounds almost like its low on fluid.

 

Had this same problem with a turbo400 and it was a plugged filter. The motorhome would move about 1/2 mile and start slipping, let it sit for awhile and make it another block. Towed it home, dropped the pan, didn't see any large chunks so I changed filter. That was 3 years ago,still going. Good luck.

 

This is identical to what is happening to my transmission...what did you find out?