Short version, I have a built tranny from Goerend, not a full build but bands, converter, shift apply strap, input etc 1 year old. My buddy got stuck in the mud with his 2500 suburban with 20' deck trailer with 3 quads and camp gear. I got him out using 4 low and high revs. The temp did not get hot at all. Now the problem is it starts in first just fine but burps into 2nd almost like it's 2nd locked. It wants to lock more and more sometimes lugging the motor. If it give it some peddle it will unlock and be fine, 3rd and 4th seem fine.

I'm going to take it in for service and hopefully a band adjustment and fluid and filter will fix it but curious what could have caused the symptoms.

Thanks

 

I'd call Dave Goerend and see what he suggests.