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Discussion Starter #1
I searched all over google and didn't get much for the problem I am having. I figured I'd start a new thread and keep it updated to conclusion so anyone in the future might find some useful info.

Backstory- I bought this truck a week ago with a bad transmission. Transmission was rebuilt a few thousand miles ago, truck was sold to company I bought it from (so no warranty) and then I bought it broken. It would drive, but started out in 3rd and just felt real sloppy with burnt fluid. It did lock the converter and shift into overdrive fine at that time though. I dropped the pan and found the valve body was actually Loose, 6 of the bolts were in the pan! I torqued the bolts, replaced the fluid and filter and it drove, but started out in 3rd gear. I adjusted forward band and then it still started out in 3rd, but would bind up on the 3-4 shift.

I bought steels, clutches and a transgo shift kit. The forward drum and band were both destroyed. I bought a used forward drum and did a complete teardown and rebuild. I replaced all the seals, but I did not install the shift kit, because it had already been done. The same transgo kit had been installed and workmanship installing the shift kit looked good.

I did NOT teardown the valve body. I just gently washed it in solvent and verified all the transgo springs were installed and mods done correctly without taking it completely apart. (I only had a day to do all this so I cut some corners).

I checked all the clutch clearances and I set the main thrust clearance to the minimum spec of .035" (it was a whopping .125" they way the last shop who built it had it set)

I did turn the PR adjust screw in 5 full turns. I made no other adjustments.

First short test drive it was shifting late so I backed off the TV cable (it was maxed) and it shifted perfect. Nice, crisp, solid shifts. It's a bone stock 160HP 12 valve with a 1500 lb service bed on it and 3.54 gears and it will light both rear tires on a full throttle takeoff and set you back in the seat. 2nd test drive I took it further and it seemed like it tried to shift into 4th around 35-40 MPH, like it tried 3 times on easy throttle 40ish MPH, just barely discernable, but then stopped trying and just stays in 3rd. No slips, no noises, nothing.

With the OD off button pressed it locks up perfect in 3rd.

I replaced the trans temp sensor in the cooler line with no change.

I put a 1000 ohm resistor in the temp sensor plug. No change.

Fluid is perfect like new, level is perfect checked in nuetral and park. No burnt smell whatsoever.

I have now ordered a shift solenoid pack and have to wait until next week.

I have also have a good friend building me a hydraulic line with a 300 PSI gauge so I can test pressures.

What would you guys do next to troubleshoot while I wait for shift solenoids to show up?

Thanks very much!
 

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Discussion Starter #2
I should add whomever rebuilt the transmission before used a lot of red silicone on the pan, dipstick tube, pump, etc. I had the cases and pump professionally washed clean, but there is a chance there was silicone debris floating inside and it got into the VB.

I used no silicone. Just Transtec gaskets and stoned/lightly sanded all mating/sealing surfaces flat and smooth. I have zero leaks (external atleast)
 

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When you get the gauge set/up first thing I would check is line pressure ? when we send a trans out the 1 requirement is a line pressure gauge so that way you know where yer at . And by the sound of it the valve body has trash in it .
 

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Discussion Starter #4 (Edited)
New shift solenoids have overdrive working good. Line pressure goes from 95 idle to 140 at WOT and 65 MPH. Shifts are real solid empty, but not as positive as I'd like towing heavy. I'm not sure I want to increase line pressure anymore with the original Dana 70 under it though.

New problem, the PCM kicks OD and lockup out semi-randomly. I wired override switches to the wires at the PCM so I can use the truck and force OD and LU to stay on as I had to do some heavy towing the other day. My god is a stock 160HP 12 valve slow with 15k behind it! Lockup in 3rd and bury the pedal to get on the freeway at 60 MPH. I have owned several stock NV4500 12 valve 2nd gens and they are reasonably powerful for what they are. I can't believe Dodge actually sold any of these with autos back then.

Anyone know if the 94-95 output shaft speed sensor runs the speedometer or is it just for the PCM? The speedometer is rock solid, so if that is fed from the output shaft speed sensor on the t-case I'd think I could rule it out.

Thanks!
 

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If you can, put a scan tool on it (perhaps a code reader will also work, but don't bet on it) and check for codes. I have had occasional issues with lockup dropping out, and have found at least one trouble code (relating to sensor voltage or ground) that did not turn on the check-engine/malfunction-indicator light. 47rh problems

If you don't have the factory service manual, there is a sticky at the top of the forum with links to download it. According to my downloaded copy, circuits T13 & T14 connect the output shaft speed sensor to the PCM (cavities B25 & B28 respectively) - it doesn't mention any difference for 4WD. I may be wrong (someone correct me if I am), but from the description of the sensor and speedometer functions, it looks like the vehicle speed sensor (notice the different terminology, per the FSM) feeds both PCM on cavity B27 and the speedometer. This is spread out over several diagrams, so you should see it for yourself.
 
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