Doing a tranny filter change on a 96 3500. I lost overdrive a couple of months ago and haven't yet figured out the problem. I was wanting to check the solenoids while the pan was down, I'm hoping someone can help me figure out how.

I see two solenoids, one that is horizontal with 4 wires and one that is vertical with two wires. I was hoping to pull them and try jumping them to see if they worked. I can't afford to replace parts I might not need. Maybe someone can tell me how to test them or what wires to jumper?

Overdrive worked fine till it all at once stopped working. I had already replaced the TPS to correct some funky shifting, which corrected that problem. That was about a year ago. Then a couple of months ago I did about 20 miles on the interstate and then hit a jarring pothole on the offramp. It has never worked since. Because of the pothole I thought it might have knocked a connector loose or something, but no luck. Lockup has never worked right. It has only locked up a couple of times since I bought the truck, both times while pulling a heavy load up a hill.

Anyone have any ideas while I'm still covered in tranny fluid?

 

i believe the two wire one is the converter lockup solenoid
other than that i cannot help you

 

There are a series of things to have the OD work , all your ducks need to be in a row .
You can just disconnect the electrical plug , connect to 12v & ground , but then you do not know if it moved all the way or not , just the click tells you it might be working .
The trans shops have manuals that tell where to put air pressure & how to run trans through a check out after building & before install .
What did you see in the pan when you took it down ?
The 1st thing I thought of was some times the brake sw can go bad or out of adjustment .

 

The one with two wires is the governor pressure sensor, the one with four wires is actually the lockup solenoid and the OD solenoid on one bracket!!

By grounding them one at a time you shoud hear a click. The ignition will ahve to be on so there is power down to them.

 

Thanks guys for the quick replies. I'm going out right now to test them.

And I did have a problem with the brakelight switch, changed it two weeks ago, brake lights would intermittently not work. Replacing it fixed the lights but unfortunately no effect on the tranny.

 

I wanted to jumper the wire outside the transmission but it seems to change colors. Any idea what the ground wire would be on the external harness? There is a black with white stripe, is that it? I just spent an hour searching other posts and could find info on the rh but the re.

It might not matter. Just cleaned the pan and there's a bit of copper colored flecks in the fluid. So now I am afraid it has wiped out the od and it is time for a rebuild I can't afford.

 

Another thing, even though the TPS was replaced and tests fine, I am still getting a trouble code for it.

 

You may have found your problem , do your resistance tests at the computer end of harness , bad connections , corrosion .
If res. is good at harness , then comp. problem -maybe , if res. is off go downstream to component till you find reason for off readings .
If the computer is thinking that its getting wrong info from TPS its not going to let the OD shift .

 

Also, if the tranducer is bad (the one made of black plastic right beside the bracket) the gov. pressure selenoid is probably bad as well. And if you change one, change the other. The transducer is what sends the info to the pressure selenoid. What happens is that fine metal wear shavings that the filter does not catch runs through the fluid. The fluid runs through the selenoid and transducer, and because the both have magnets in them, they stick and go bad.

 

I also just got a code for the VSS which I don't think I have had before. There are two connectors on the back of tranny, one with two wires and one with three wires. The one with two wires is cracked and has oil and junk in the connector. I cleaned it but no difference. Is this the VSS and if not what is it?

Until I get it fixed, how many rpm's is it safe to run these engines? I have to travel about 120 miles every day, most of it interstate. My tach shows about 2400 at 55 mph. I have been keeping it around 50 mph but I'm going to cause an accident sooner or later when everyone else is running 75 or more.

 

VSS , thats the speed sensor , if its bad it could cause lack of OD also , need a meter to check most of this stuff , a scope will catch all but anything els maybe too slow in finding a movement sensor & all glitches .
Theres not much fueling after about 2200 RPM , so the problem is not going to be over revving , thats closer to about 3000 .

 

I believe a 96 only has OD & LU solenoids. I believe a three wire connector is behind and above the neutral safety switch. The outer wires are grounded by engine controller to allow OD & LU. The solenoids should have approx 30 ohms resistance.
I believe a eight wire connector has electronic governor and two wire would be a non lockup trans. The 96 should have a real governor.
The amount of metal does not seem excessive. Look for a glop of brass or aluminun about volume of a quarter as normal on unserviced unit. A black krispy creme donut sized mess for magnet would probablly be a problem.

 

hi
about the tps i had one go bad in dead of winter so dealer charged 100 to diagnos it and did not have one in stock <thank goodness 385 !!!!>

went to napa got one 200 ,
installed it wow gor er now ?
4 mounths later trany acting weard agin compleatly diff than first time !!
so just for fun and to satisfi my own mind i drilled 2 1/8 holes in the old one sprayed it with brake cleaner till it came clean .
resealed with 2 dabs of silicone and reinstalled it

trany now 6 mounths later still working PERFECT !!!

so even a newer tps could be the problem !

napa would not refund my money but did give me another tps , i got it in the glove box !

trany fluid atf+4 wallmart !

 

I just had the same symptoms and I replaced the transducer and the solenoid.Its great now.Did you notice any loud clicking sounds when you were at or near od speeds?