Breese1975

I have a new valve body for my 03 2wd 4l60. Will it work in my 99 4wd 4l60. Os the a difference? Thanks in advance.

strutaeng

Post #10 I think should have your answer:
https://ls1tech.com/forums/automatic...nge-100-a.html

Why are you trying to swap the valve body? You have a bad transmission and a good valve body on another transmission or vehicle?

Breese1975

the valve body in the 03 transmission is brand new. It kept losing 3rd gear. We determined it has a cracked case. I just bit the bullet and bought a new TCI streetfighter. Now i have a freshly rebuilt tranny with 3rd gear out. My son's 4x4 is shifting hard from 1st to 2nd. I was going to put this new body in it.

strutaeng

Ok, makes sense now. My 1999 Silverado also developed that hard shifting 1-2 and had a P1870(?) code. It's the TCC valve in the valve body I assume you already know? It's a common problem. Transgo or Somnax make a valve to upgrade but you have to ream the bore on the valve body and the reamer and valve run about $150 last I checked.