TH350 hanging onto 2nd
 

The truck is shifting well from 1st to 2nd, but hanging onto 2nd before shifting into 3rd. Sometimes shifts right into 3rd, sometimes hangs in 2nd. Fluid levels are fine, shifter is fine...is my transmission taking a dump on me or could it be a vacuum leak or bad solenoid?
This just started today-

I'll add that the transmission was rebuilt about 30-40k miles ago

Re: TH350 hanging onto 2nd
 

sounds like maybe the modulator valve, or maybe a hole in the vacuum line going to it.

Re: TH350 hanging onto 2nd
 

I would say either something with the modulator or maybe some debris somwhere in the valve body. Might be a good idea to do a really good fluid flush.

Re: TH350 hanging onto 2nd
 

That would be my guess?!?!?

Re: TH350 hanging onto 2nd
 

Modulator valves are $13. I think i'll get some new hose and throw one on there...after doing a little gooogling i read some and it sounds spot on for a bad mod valve or vac leak.

Re: TH350 hanging onto 2nd
 

x2 vacuum line or modulater were my first guess.

Re: TH350 hanging onto 2nd
 

Mine started doing that on my truck. At first I could get it into 3rd by giving it a little more gas but that eventually quit doing it though. I changed my modulator and checked my hoses and fluid first too. I had to get it rebuilt. The clutches were gone. The bad thing was I had two trucks at the time and both started this within two weeks of each other.

Re: TH350 hanging onto 2nd
 

when it rains it pours, or at least around my house it does!

Re: TH350 hanging onto 2nd
 

if all else fails put some trans x in it the stuff in the silver and blue jug.Works everytime ive ever used it.

Re: TH350 hanging onto 2nd
 

I just replaced the modulator and rubber on both ends of the vacuum tube. When I pulled the old modulator off, there was a little fluid inside. Not too much which makes me think that it just started going bad.

It's shifting good now, i'll keep an eye on it and see if there are anymore issues, but I think I have the problem solved. It was a very simple operation (w/ the help of David's lift, etc.) and I figured yall would like some pics. Yes, it is very wet...

Thanks for the help fellas