I bought a 1994 Dodge 2500 4x4 as a back up truck. It has 141,000 miles and is completely stock. I bought it with a blown trans. I put a remanufactured Auto in it and it shifts great. The first week I drove it, it bounced between overdrive and 4th alot. Then it started to stay in OD like it should at higher speeds. The last 3 weeks it has gotten progressively worse. At first it would not stay in OD unless over 70, then it wouldnt go to 4th until I was over 50, then 60, now it just has 1-3 and never 4th or OD.

This has me stumped. The fluid is full, all fuses are good, grounds are clean. I took to a trans shop and they said the new trans is in fine shape and its not internal, and it has electrical for 4th and OD. I paid for diagnostics, they said it was the Throttle Position Sensor. Just put a new one of those in today, still wont come out of 3rd.

Any other ideas? I'm tired of throwing money at this thing for guess and check! Especially elec. parts that can't be returned!

 

Getting any codes? (CEL on?)

4th gear, and TCC lockup are both electrically controlled. 4th will be disabled if the PCM thinks the trans is too hot.... (but, won't necessarily set a code.....) If the check valve is still in the trans line going to the bottom port on radiator.... get rid of it. There are a couple DIY's in the FAQ section here with a couple different methods of doing so.

Does your speedometer work as it should?

Welcome to DF.

 

I gotta wonder if something's loose on the TV cable.

 

Thank you for the help.

The truck is not throwing any codes, the speedo is working fine also.

The truck shifts and holds the gears perfect from 1-3. It hits 3rd about 35mph then it doesn't matter if you accelerate fast or slow it will hold 3rd until you have no more pedal. Since the trans worked ok for a while I have put 1,100 miles on it already and the trans fluid doesn't smell burnt at all, so I don't think the fluid is overheating? It has gotten progressively worse, It used to hold 3rd until 50 then hit 4th then OD by 60 or sooner. The next week of driving it wouldn't hit 4th until 60 mph and OD until 70 and it would bounce in and out of OD.

 

How old is the trans? Still under warranty? If so, I would take it to wherever you got it from, and see what they are willing to do. Obviously something ain't quite right there. You should not be paying for diagnostics either, unless the shop can PROVE that whatever part they are pointing their finger at is indeed the problem.

 

my buddy had the same problem. the problem is more than likely your noise filter and the tc is coming out of lock out mode, there is a wire coming off the alternator going towards the passenger side, throw some tin foil around it and see if that will fix the problem.

might fix your problem, and its free

 

The trans is only a month old tops. Yes, it is still under warranty. I bought it as a remanufactured trans and had one of my employees install it. Since it has him stumped I took it to a trans shop and paid for those diagnostics. They said it was for sure electrical and then traced it to the TPS. They wanted $620 to put it in, so instead i had my mechanic do it but it didnt fix it.

What will wrapping tin foil around the wire help with? Is it to reflect heat? Because the trans functions the same way weather its hot or cold.

 

2nd gen dodges only have 4 speed automatic transmissions. What you think is 4th and OD is really OD and the torque converter clutch locking up. OD should be first and lockup second. The truck will not lockup in 3rd unless the O/D off dash button is pressed.

Definitely look up the Throttle valve cable (TV) adjustment procedure and make sure the cable is acting properly.

Make sure check ball is eliminated.

The 1994-95 trannies have a an actual governor so no really expensive electronics to replace. A bad would likely cause the trans to not upshift through 1-3 so that appears to be functioning properly. OD and lockup are engaged by the computer. There is a 2? prong (can't remember exactly might be 3) connector on top of a bulge on the drivers side of the tranny towards the rear of the main case (not on OD unit). Make sure that that connection is clean and properly connected.

 

no, what the foil does is reflect any engine noise that might sneak through the wire to the cpu and tell the tc to switch out of lock out mode, if your noise filter is bad it would definately make that trans act up, try that and let me know, my friend had the same prob with his 98. go to a tranny shop and ask them if there is any way to check the noise filter.

 

Are you joking? Yes the foil will reflect heat from the engine which reduces electrical noise that may cause the computer to act in an odd way (if this is really the problem). The noise we hear from the engine will have no effect on electrical signals.