transmission problem

[Fendley]

hi guys, new to the TDR web site. i have a 92 std. cab d250. 500,000 plus miles on the engine. transmission has been replaced once within 25,000 and then has been rebuilt on average of 150,000 miles inbetween. it is the A518 automatic. i have had the tranmission flushed and installed the 440 capacitor in the wiring harness. the problem i am having is in warm weather say above 70 degrees the transmission does fine. but under 70 degrees every time i take my foot off the throttle it downshifts. i can't get a good answer from local transmission shops. need help. thanks in advance.

 

[ChenoweG]

Similar issues

Also new to TDR and having similar shifting problems. I have a 92, 2WD D350 dually with the auto and about 158,000 miles on it. It hasn't been rebuilt.



When accelerating and approaching 50 mph it hangs and won't shift into overdrive. It finally does shift up while letting off the accelerator sometimes. Sometimes I can't even get it to do that. Occcasionally, it will do the same as Fendley described and shift down when letting off the pedal when in overdrive.



I am thinking of getting a rebuilt trans but if I can make this one last a little longer I would be happy. Any suggestions?

 

[DEdds]

Good question.....

 

[dpuckett]

TPS- Throttle Position Sensor; or Total Piece of S***. It is the reason I sold my first CTD, which happened to have an auto. They are adjustable, and can be disassembled and cleaned. Sometimes, they get to the point you cant clean or readjust them. They run about $140 new from cummins or local parts store; $200+ dealer 7 years ago.



ANother option is to install a potentiometer (sp?). Have no idea, never heard of one til I read about it here.



Daniel

 

[KOG]

What's the 440 capacitor? Hadn't ever heard of that one.



The upshift into OD problems can often be related to the TPS. OD solenoid in valve body can also cause trouble. Those things are covered in the transmission thread that's somewhere in this board.

 

[Philip]

Here is a link with info on the TPS.



http://www.piersdiesel.com/Tech1GTPS.htm

 

[1stgen4evr]

Almost certainly the TPS. It could be a ground problem but if it has not been replaced in all those miles, it is due. Total Putrid Stupidity just like Daniel said but the computer is waiting for a signal fron the TPS to do its thing. Our trucks would be so much better without the computer. Did you know that the 89 didn't have one?



Do some digging in the archives. This has been discussed THROUGHLY. Some members have deleted the TPS.



DO NOT remove the TPS and drive the truck. The little connector between the throttle arm and the TPS will be lost and the only way to get one is buy the entire bracket. VERY COSTLY.



If there isn't any malfunction with the AC and the charging system, you probably don't have a computer problem.



Like I said, dig in, the info is here.



James

 

[ChenoweG]

Thanks folks, looks like an investigation of the TPS is due!



G

 

[Fendley]

The capacitor is covered in a previous TDR magazine I don't have the vol. #. It is suppose to filter out any voltage spikes caused by the tps. It did help the shifting but did not fix it. Much obliged on the responses. After 1stgen4evr posted I researched further back. Found alot of good info. First computer I've ever owned, still learning how to do some things.

 

[1stgen4evr]

"i can't get a good answer from local transmission shops. "



Not surprising, they are in the business of changing out trannies and if you don't need that, not much way to make $$$ off you. There are some shops that really know the 518. Find one before you do anything again. But do your homework here first.



Keep in mind that every problem you will ever have with a first gen has already been discussed here. Don't hesitate to ask questions. I and others will jump in usually with at least partial answers.



The collective knowledge base with the membership is actually awesome. And that isn't hype.



James

 

[ChenoweG]

Whats the difference in the TPS

I was searching on NAPA's website for a replacement Throttle Position Sensor. After going through the paces of make, model, year... . I got two parts under TPS.



Throttle Position Sensor (TPS)

CRB 229323 $239. 00

w/ OEM # 4638631, 4720081, 4728881, 4746965



Throttle Position Sensor (TPS)

CRB 229923 $44. 99



They look different in the pictures. I haven't looked under the hood yet, still at work. Keep in mind, this would be the first repair I have had to do to the dodge since I have been driving it.



I called my local Dodge Dealer and got quoted for the TPS...

Part # 4746965 w/ bracket $659. 00

Part # 4746966 wo/ bracket $315. 00



This seems a far cry from the internet.



Thanks for all your assistance.



G

 

[Philip]

The first part number listed is what your truck should have on it.