Tranny is on strike

[ExpDann0]

I have noticed with increasing regularity that when my engine is cold, the engine almost goes to redline before the transmission shift from 1-2. When the engine is warmed up, the transmission is more cooperative. I had the ATF changed, doing a full tranny flush, with no improvement. I have 130K on the truck, with mostly highway miles. Any thoughts??

BTW: I did notice a vacuum hose that was disconnected from the vacuum tree at the rear of the port.

 

[TPLYNCH]

Could be a bad modulator. see here for more info Dead Link Removed

 

[Kadarom Douhrek]

It could be a sticking speed govenor.
Dead Link Removed

 

[410Fortune]

did you re-connect the vacuum line and try it again?

If it is indeed the vacuum modulator line that goes down to the tranny it could be the problem or part of the problem.

Now you also need to check your ATF level, especially after having somebody else service it. Did they change the filter as well as the fluid?

 

[ExpDann0]

I have the top end tore down right now. If the hose to the modulator connects to the vacuum tree on the port and it or other hoses were disconnected, it probably upset the required pressure in the tree itself, thus causing a malfunction. Lets hope...

The ATF level was full. No, the filter was not changed; I was going to do this in a bit.