Whiney Transmission

[Portland Suburban]

Ok, so here is the deal. We replaced the VRV so that I had normal shifting. Now I have wimpy, early shifting. Before, I had hard late shifting. Anyhow, now I also have a whiney tranny.

Let me explain.

In the morning, if I put the tranny into first gear, the tranny makes this high pitch noise until I put it in second and then almost goes away after I put it in drive.

This of course all goes away when it warms up. When I drive it at lunch, there is no noise.

What is happening?

[NH2112]

Getting a TH400 to shift properly can be a real pain on a 6.2l truck. It's more trial and error than it is following a fixed set of steps, but the procedure given in manuals like Haynes' Diesel Manual are a good start. Basically, you need a vacuum source (MityVac or other pump) and a couple gauge blocks to set the TPS and VRV. You may also have to make adjustments at the vacuum modulator, replace it, or replace the TPS.

[Portland Suburban]

Well, I found out the problem-or the problem manifested itself. Tonight, the tranny toasted itself. Yep. Just stopped. No forward gears and dies in reverse. Something wierd going on. Looking for a good th400 around town here. We shall see how things go...

[dieselcrawler]

I have a gasser K-20 with the same trans, doing the same thing... can I expect the same results, a trans that will be leaving me stranded soon? Could it just be low on fluid? (I will make sure to check that as soon as I get to the truck later today...)

Thanks...
Greg

[4x4Dreamer]

I think that whining sound is indicative of your pump getting ready to go kaboom. At least, that's what mine did.