I have a 1994 Ram 1500 5.9 4x4 A518 auto. Suddenly while accelerating from a stop light, the trans started sound like pump cavitation and lost forward motion. Coasted a bit went back into gear but now slip, cavitation and out of gear. Shut off engine and after a minute start up and can drive slowly for another minute and it repeats. About to pull the pan as seems it is pumping air just at the normal fluid level. No leaks and I had just checked fluid level before the trip. What should I be looking for?

 

Anything that shouldn't be in the pan. Your trans is purely hydraulic controlled, only electronics are for TCC and O/D..... I suspect the contents of the pan will tell the tale.

 

I have a bit of assorted debris in the pan. Likely the filter is my problem. Appears the filter is very dirty and has failed next to the fluid inlet. So I don't know how much contamination may have gone past the filter. I just looked at schematics and see there is a screen on the pump output, one other in the governor feed. Is the pump screen accessible at/in the valve body? Location? Thank you.

 

Don't know...... Toss a new filter in there, some fresh fluid, see what happens.

 

Yes, i could have just done the filter change. I decided to pull the valve body and find the pump outlet screen. Yes it was clean. What surprised me was aluminum paint chips in the pan besides the small amount of aluminum shavings and clutch material. Hair around the magnet. On reassembly, I noticed that the accumulator piston seals seemed shrunk or worn and no resistance in the bore. Bands look great and were in adjustment. Drums looked fine, no scoring or discoloration. Of course I had no replacement seals so put it back together, 8 qts +4 and road test very good. Maybe the converter clutch lockup was a bit sharp. Possible source of debris?
A while back the trans cooler line clip melted out on the trans while I was pulling a trailer. Found the service bulletin last week about that. Well this trans has been through a bit and looks pretty good overall.
It was the filter for this episode and now it ain't broke so I'll run it till something else happens.

 

If you still have the check valve in the trans cooler line, make it go away.

 

I don't see a check valve in the trans cooler line, nor is there a temp sensor. However there is a plug hanging down the left side of the trans with nothing to plug into and I have a constant code 37 in the ECM. It also drained quite well a couple years ago when the coolant line plastic clip melted in the fitting.

 

Check valve should be in the cooler line running to the bottom fitting on the radiator, right where it changes from steel, to rubber line.

Temp sensor was part of various heavy duty packages on the pre 96 trucks. So, real possibility that you don't have one. It would be external on yours, right near the trans.

 

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