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Do I really need to overhaul my transmission?

I have a 1997 Dodge Ram B3500 van with RV conversion by Roadtrek. At 108,531 miles the check engine light came on, the dealer replaced the transmission (XM) output speed sensor, pulled XM pan and replaced 4.5 qts XM fluid, plus filter and gasket; replaced power steering high pressure line, filter and fitting, XM fluid color ok, as was goop on xm pan magnets. Cost $400.

At 108,564 check engine light on again. Computer found fault for govenor pressure above 3 PSI in gear 7 starts ago, and 3/4 shift solenoid no rpm drop 7 starts ago. Has 2 good trips. Light will cycle off after 3 good trips. Due to dirty fluid, may be some debris in the system. recommend driving on freeway… Went to Oregon.

At 109,393 the check engine light came on again, o/d pressure is only 30 psi. The Oregon dealer said the transmission needs an overhaul, $3185 or replace $3335. We then drove another 800 miles with the check engine light on but no problems. Do we really need to overhaul the transmission?

We currently use it 3 times a year, and my impression is we’ll gradually lose overdrive power and hence some gas mileage. Is that all? Thanks so much for your help!

How about telling us what the codes were, for the CEL (Check Engine Light) It will be in the form [P1234] How about takeing your car to an auto parts store and ask them to get the codes for you. Many stores will do it for free.

Is the van worth $3500?? I would drive it until it will drive no more or until you KNOW something is wrong.

You might be better off with an older B3500 with a 360 engine and a non-computerized transmission. No CEL’s and repair costs will be about half should the tranny or engine die…

I’d try Auto-Rx to remove any debris that’s fouling anything internally. It requires a full fluid exchange via cooling lines. Your filter is new enough not to bother changing it again. I’d also install a Magnefine filter in the cooler line too. While your trans is surely more sophisticated than my 30RH in my Wrangler, it cured a stuck/sticking throttle position valve in a few hundred miles. Google it.

Thanks for the response. I will go to the parts store for codes once this storm abates. Neither dealer included the actual codes in their reports. The first time they noted that they found fault for govenor pressure above 3psi at zero miles an hour. ran tests per flow chart. found input/output speed sensor ratio faults. replaced output sensor and found and repaired input sensor connection fault. The second time govenor pressure above 3 psi, and 3/4 shift solenoid no rpm drop 7 starts ago was in history, but no active fault. The third time, in Oregon, they could measure overdrive pressure at 30 psi.

These transmissions had problems with the governor pressure sensor (Transducer) Have these been changed?? This is a very common problem. Who is telling you that you need an overhaul?? Is it a transmission shop or the dealer??


A dealer in Oregon while we were traveling. We declined and drove another 800 miles. Our dealer here says keep driving until there’s more of a problem, but didn’t offer anything about the transducer.

Apparently it’s worth about $15,000 if the transmission is working. My local dealer agrees with you about driving it until there’s something more serious wrong.

I think you should drive it to transman618, if he’s not too far away ;o)

Has anyone verified the sensor’s electronic pressure readings with a transmission pressure gauge?

Thanks to all your coaching, we did take it to AAMCO. They pulled code PO783. They are going to work on the torque converter because of no lock up, no overheating. We’re going to add some more heavy duty components to the transmission because of the extra weight in the Roadtrek conversion. Thanks again for your help!


1/25/10 Aamco ran the diagnostic P0783, and now I have two bids, one for $3109, and one for $2570. Both are for a reconditioned transmission service and exchange rebuilt Torque Converter with 12 month limited warranty. Both have new assembly set, new ATF fluid, new filter, 6hrs remove & reinstall, 9 hrs rebuild, 1 Exh rebuilt torque converter, 1 new gov pressure sensor, 1 new gov pressure solenoid, 1 new OD Brake steels, 1 new bushing kit, 1 new bearing update, 1 new OD snap ring kit. The more expensive version also has 1 new planet (what’s that?), 6 Kolene direct/forward steels, 1 new front kevlar band, 1 new transgo shift kit. Should I choose either, or get another estimate?

Once a transmission has been disassembled, your stuck. The cost of the work so far and taking it to another shop makes no sense unless you’re unhappy with them. I’ve had many people come to my shop after the fact and the rest is history. Replacing the planetary system is not necessary unless they can show wear on the gear or washer set. Make sure you get quality components, a shift improver kit and especially a good quality external cooler and proper installation. TruCool makes a excellent cooler. Good luck.

You really need to have that governor pressure sensor and transducer checked/replaced before even considering overhaul. This is way too common of a problem and your mileage is rather low to overlook this.