I just purchased a used 94 Z71. I'm having some transmission issues with this vehicle and was hoping someone here cold give me an idea if I need to have the tranny rebuilt, or if there is something else that makes sense.

When the transfer case is shifted to 2H or 4H, it takes a lot of rpms to get the truck moving. When in 4L, the truck moves as it should as soon as you remove your foot from the brake.

Could this be internal valve issues in the tranny, I would assume if the problem was tranny, the truck would act the same whether it was 4L, 4H, or 2H. I'm tending to think there is a transfer case issue.

I have not pulled the pan to inspect for metal or other issues in the truck. I know very little about tranny's, have very little room to work and was thinking of taking it to a shop for inspection. Before I do that, I'd like to hear everyone's thoughts here.

Thanks,
Will

 

sounds like clutch to me if it was tcase u wouldn't move

 

What Doug said,

In Lo range, there is very little load against the transmission and it is able to pull the truck; up in Hi, it is just cannot handle the torque.

How does it act in reverse?

Allan

 

Reverse is the same as in drive. Takes off in low, but very slow response with highe engine RPMs in high.

 

From what you say, sure sounds like that transmission is cooked. Pull the dipstick and you'll probably see black oil.

Allan

 

How many miles on the tranny?

 

I'm not sure of the miles on the tranny. The truck has approx. 260K. engine was rebuilt maybe 50K ago.

I kinda put the tranny issue on the back burner because when I was under the truck checking the transmission linkages, I noticed a head gasket leak. So for the last three days, I've replaced head gaskets on the truck. Noticed several broken vacuum lines and replaced all these. After starting the truck and getting timing right, I decided to check the tranny oil. Guess what? That's right, it was off the dipstick. Put 1 quart of Lucas Trans Treatment and 1 quart of Dex/Merc into the tranny, which put the level about right. Started it up and "BAM" tranny is running and operting as it should. I'll have to get under there and drop the pan and replace the filter, but right now it seems to have been just low on fluid. Kicking myself in the but for not checking it first. That's way I get for assuming the guy I bought it from was keeping up with the maintenance. I know better now especially after seeing the condition of the hoses and wires under the hood.

I do have one other question tho, there seems to be a vacuum assist hose running from the transfer case to the engine somewhere, this hose has been cut and capped. Any idea where it's supposed to connect on the intake?

 

You're still low on oil.

Check it hot, running and in Park or Nuetral.

That hose on the transfer case is a vent. The "cap" on the hose is the breather.

Glad ya got 'er going,

Allan