Hi all, new here and new to Dodge trucks, for that matter. I bought my Dad's 1992 D-250 Club Cab that he doesn't drive anymore. He had an accident on a 4 wheeler and now drives a differnt truck due to the A-pillar configuration and his need for extra room to get in and out. He hasn't driven this truck for 6 years, and it has 109K miles on it. Practically brand new.

We checked everything over real well, both of us being fairly mechanically knowledgeable but me being a Chevy (actually an AMC) man, I defaulted to his experience quite a bit. After we were both satisfied all was well, I drove it from Indiana to home in Oklahoma. All went well on that trip, so I did not hesitate to drive it from OK to CA, where I am now -- and thats when the problems started.

About 400 miles from San Francisco (my final destination) the transmission started slipping between overdrive and the last gear (I think third -- these are 3 speeds + OD, right?). At first, I thought it was just due to me not maintaining enough speed and thus natural, so I started paying attention to the speedo. Then it started slipping out in 65, and I knew something was wrong as it seemed to shift at about 55 before. So I stopped at the next fuel station (which was 40 miles up the road -- yes, I know, prolly should not have driven it that far -- hindsight is always 20/20) and checked the fluid in the tranny, it was low by a quart so I filled it up and got back on the road. Worked fine for about 75 - 100 more miles, started doing it again. I stopped, checked the tranny fluid and again it was low. Filled it up. I checked the stick at least five times to make sure I was getting good readings. Now what I cannot figure out is where the fluid was going. It wasn't going on the ground and it wasn't going into the radiator through a bad cooler.

After filling it, I called Dad and he told me to lock out the OD using the switch on the dash which I did. Thus far, no further tranny problems and the fluid level has remained at full. I have searched for solutions to the problem of OD and see there are about a million and one possible causes including everything from relays to bad tranny seals. I really do not want to just take this to a dealer who is going to insist that I need a new tranny. If anyone has some guidance, I'd be eternally thankful.

And, I doubt this is related, but my injector pump has developed a small fuel leak (drip) and is in need of seals. Mechanic told me not to worry about it, drive it home.

 

Sounds likes its hunting between overdrive and drive. Most likely cause it the TPS on top of the injection pump. At this age they either really need a good cleaning and adjustment or you need to wire in one of the fixes some of the members here have done. Most are in the sticky.

 

I'd agree with JD, check your TPS (Throttle Position Sensor) on the top of the injection pump. I Fiiiiiinally checked mine, after replacing almost everything else only to find that a 2.5 cent hex head bolt was rounded off enough not to give the TPS a good voltage reading!

Read Here... http://www.pdrdiesel.com/oldsite/Tech1GTPS.htm

 

Hmm, OK, I looked at mine, and one of the bolts that holds it in is missing and/or broke off (cant tell which) it appears to only be held on there by three of them. It picks its ground up using that? Is this something I should attempt to do while not at home (i.e. in the hotel parking lot), or do I need my facilities to do this? Should I just replace the TPS rather than trying to adjust it?

 

if you have a volt meter with you it easy is to adjust/clean. if that does not work you can either use a potentiometer to control the OD shift point or replace the tps sensor. there is a good how-to on the potentiometer install in the sticky.

 

I like the POT Fix myself. For the price and still maintains the correct factory wiring you cannot beat it. As for the long trip it could have been the trans fluid sensor that is plumbed into the line underneath. Temps too cold, no OD. Temps to hot no OD. Temps correct, OD works.

 

So it does have a sensor that cuts the OD off if temps are too high or too low? Where is that thing at, and is there a way to test it? What about a way to override it to see if thats truly the problem?

I'll buy a voltmeter and check that out as well, that sounds relatively simple.

If I do the POT Fix, does that effect anything else like disable cruise control or anything like that?

 

the sensor is on the hot line coming out of the trans pan. i don't know how you would go about testing it. maybe someone else will chime in...

 

If anyone does know how to test it, please let me know.

I am about half way home, so I am just gonna mess with the TPS when I get home and see where that goes. I really dislike doing my repairs in parking lots and driving home with no OD is not quite as miserable as I thought it would be.

Thanks for the info guys, really appreciate it!

 

OK, tested the TPS sensor finally. It is coming back with a reading of 0.2 VDC at rest and 0.6 VDC at the floor. That means its bad. Now, if I do the fix in the sticky with the POT, does that have any side effects like disabling the cruise control (it doesn't work now, but thats one of my next projects to fix).


Other, new issue: I have a new noise today. With the truck in park on level ground and the engine idling, I have a what sounds like a little clicking sound coming from the transmission. If I put it into neutral, it goes away. Any ideas? I had an AMC Eagle that did this as well, never resulted in a dead transmission so I am not too worried, but I dislike little noises, makes it hard to hear the noises that matter if you get too many of them.

Finally: Does anyone know of a good wire to tap that is hot only when key is in ON or ACCESSORY position? I want to throw a relay for an accessory bar which is right now wired direct to the battery and thus always hot.

 

If anything, it'll make the cruise control work better!

 

Excellent. Thats what I was hoping to hear.

 

Well, so we replaced the TPS sensor and the overdrive still is hunting. Seems to take about 50 miles of driving before it slips out for the first time and then it starts hunting. I am now thinking a flaky temperature switch. Any idea where I get one of those? Autozone don't seem to have it.

 

Jumper it to test your theory. The dealer can get one for you if it's actually bad.

 

Is it normally open or normally closed?