I’m at a loss of what to do from here me and a buddy just rebuilt my 4r100 with stage 2 clutches and transgo shift kit we got it all back together goes into all forward gears wonderful but won’t move in reverse almost like it’s binding. The pressure in reverse seems to be low and lower than what I’d like to see in some forward gears I dropped the pan today and checked to make sure all the valve body is tight it is. Now I’m leaning more towards the pump but wanna get other peoples views before I tear it down again. Thanks.

 

Are there codes stored in the PCM?

 

No codes it’s definitely not electrical I’m thinking it’s something with the pump we got a pump new from eBay with a non pwm lock up in it. we put a sunnex spool valve in it to upgrade it so I’m wondering if we didn’t install it backwards or wrong but I’m gonna go into work early tomorrow and yank her out and see

 

I used a transgo boost valve the other one we built, and I put a sonnax one in mine. The sonnax one is supposed to be better because it has o rings on it that seal it to the pump body rather than metal on metal like the stock aluminum one, and the steel transgo one. But maybe the o ring blew or something goin in

 

Maybe just give it more time? Put it thru it's paces.