Well I posted before about no being able to downshift to 3rd after a re-build and TransGo install. I was able to go to 2nd then to 3rd but never from 4th to 3rd. It would also go into 4th even when the lever is in "drive". Read about it here:
https://www.thirdgen.org/techbb2/sho...threadid=53974

UPDATE:
Now I don't really have 3rd gear. I can accellerate in 'drive" or "overdrive" and it will skip 3rd and go right into 4th. It does this at part throttle and full throttle. Bogs the engine down bigtime. I need advice.

 

For it to do that it would require the band to stay on in 3rd. It is possible that the Servo has a leak in a ring and get a similar problem. I am sending you a direct E-mail on this problem.

 

FIXED!!!

Turns out the trans-go was fine. I had also did the GM 3-4 upshift valve to allow for full throttle 4th gear. That was the problem. The GM valve was designed for 2nd design VB's not 1st design which is what I have. I put the orginal back in with the orange trans-go spring and all is well.

 

Hows the upshift 3-4 kit? How do you downshift to 3rd to pass? Do you manually have to downshift it to D?

 

Hmmm, I am glad as can be that it is fixed but... I am under the impression that the GM valve does work with the 1st design VB. I will investigate further.

 

I see that the 3-4 shift valve & the Trans-Go Shift timing springs that I sent you worked out ok? Hmmmm....

 

I removed the GM 3-4 upshift valve. It DID NOT work for me, it made 3rd very, very short, it went right into 4th even with manual 3rd selected. I do not recommend it in 1st style VB's

I put the orginal 3-4 valve back in with the transgo orange spring. All is well. I do have to do a manual downshift after about 55mph due to the design of the transgo kit, below 55mph it will automaticly kickdown with throttle.

 

I didn't have to use them Dana, GMTech found my orginal 3-4 valve in his toolbox. All is well now. I don't suppose you can take them back? No big deal if you can't. I'm so happy it's working fine.

 

I don't see how, it block's off too many passages in the VB. Not even close to the orginal early style valve.
You can't use the transgo supplied spring for the 1st style VB with that valve, I had to use the 2nd style spring to let it fit. It really didn't make sense. It's out now and the orginal is back in working fine.