• Welcome to The Truck Stop! We see you haven't REGISTERED yet.

    Your truck knowledge is missing!
    • Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
    • We have tons of knowledge here for your diesel truck!
    • Post your own topics and reply to existing threads to help others out!
    • NO ADS! The site is fully functional and ad free!
    CLICK HERE TO REGISTER!

    Problems registering? Click here to contact us!

    Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!

No overdrive

H

Hudson546

New Member
Messages
14
Reaction score
15
Hey guys I picked up a 1994 Chevy 2500 with the 6.5 diesel. I got it cheap due to a mysterious transmission issue. It has the 4l80e and it refuses to go into overdrive or exceed 40mph.

I pulled the codes and got 73 81 and 82 and if I’m correct are all transmission related solenoid codes.

I’m not a mechanic by any form of imagination and my electrical knowledge is even less impressive, but I find it hard to believe all of these solenoids would go bad at the same time. I would be more inclined to believe a bad solenoid if it was one or even two of them. So with that being said does anyone have any suggestions on where to start with this problem? I know this kind of thing wasn’t unheard of on these trucks.
 
Leroy Diesel has a program that will load into a computer.
It might help determine what the problem is.
You could try cleaning every ground connection You can find.
One bad ground could cause multiple solenoids to fail.
 
Welcome to TTS..as for electrical, these trucks can be a nightmare. But I agree(1 not likely all solenoids failed at same time..but a bad ground/ cable can do all kinds of crazy things.. definitely clean grounds, especially the one with 3 different cables on it at back passenger side of the intake..right below the tranny dipstick.
I'm sure other guys will also chime in soon with advice and there experiences.
 
Fluid isn’t burnt at all and no I don’t own a scanner but if someone can recommend one that won’t destroy my bank account it would be appreciated. This is the only OBD1 vehicle I own
 
I guess to add how are you guys scanning these obd1 computers? Everything I can find for odb1 is a code reader which basically does the same thing as using a paper clip.
 
one option is:
Leroy diesel sells software for a laptop, buy the software and aldl to usb cord online about anywhere and you can pull from that.
Maybe someone here that has it can let you know before getting it that it does in fact read everything for the trans also? @Burning oil

another would be get a knock off tech 1 scanner from ebay.

then there are other companies that make scanners like otc that can read obd1
 
Do you have a link to the eBay one? Everything I can find is either obd2 or somthing you plug in but still requires you to read codes off the dash
 
No, i seen them over the years there looking for other items . Might call Leroy and verify first that it is good for that. Then ask him where to get it- he might sell them also, I’m not sure. I have an old MAC Mentor (made by OTC Genius)I used last - probably 10 years ago.
Leroydiesel.com
713-408-0423
 
Will L. said:
one option is:
Leroy diesel sells software for a laptop, buy the software and aldl to usb cord online about anywhere and you can pull from that.
Maybe someone here that has it can let you know before getting it that it does in fact read everything for the trans also? @Burning oil

another would be get a knock off tech 1 scanner from ebay.

then there are other companies that make scanners like otc that can read obd1
Click to expand...
There are no tech1 knock offs, just the tech2. And ebay ones are very hit or miss(more miss than hit). But for a 94/95 6.5l your only options are gmtdscantech or a GM tech1 or tech2. Thats it.
 
Hudson546 said:
Sounds like it’s going to a shop to get scanned then
Click to expand...
FYI, most shops cannot fully scan a 94/95 6.5l. The OTC scanners provide a good data stream on them, but not so hood when it comes to dvt controls and special functions. Even most dealerships don't have a tech1 laying around anymore, have lost there OBD1 cables for the tech2, and cannot connect to it with the current MDI I or MDI II.
 
Its old enough to be considered a classic. And classic owners know they often need to own the specialty tools even if they are paying a mechanic to use them. Sux, but is what it is.
 
Welp........ I think I found the issue. Internal harness connection was broken so i dropped the pan to replace it. Pan came off and out spilled strawberry milkshake so somehow either coolant or water has gotten in with the trans fluid. (Kinda odd since the fluid looked bright red on the dipstick a week ago)

anyways here’s some pictures of what was inside. So now I guess the question is what’s the most likely place this coolant or water is being introduced at radiator, trans cooler, pan gasket? I hate to put another trans in only to have this happen again
 

Attachments

  • 85C4A10A-5DC1-4B03-A639-F7883B785326.jpeg
    85C4A10A-5DC1-4B03-A639-F7883B785326.jpeg
    181.5 KB · Views: 9
  • 295C69A3-B8F2-48EA-8F49-E5F61DBB5CD8.jpeg
    295C69A3-B8F2-48EA-8F49-E5F61DBB5CD8.jpeg
    211.6 KB · Views: 9
Do you have a tranny temp gauge? That looks like either (a) you boiled the hell out of it..or (b) did you add fluid recently and possibly put wrong kind in? Like regular dex/Merc than accidentally added synthetic?...just ideas. I'm not tranny expert. But that I know of coolant don't go in tranny.. tranny fluid goes up to tranny cooler to cool it off then back to tranny..but I could be wrong.
 
You must log in or register to reply here.
Back
Top