New tranny wont downshift to 1st

[SloRegal]

Well, got the tranny back yesterday, slapped it in today and it shifts a little firmer than it did before but it wont downshift to 1st. It does it all the time but I can manually shift it to 1st. What do you think would cause this can it be fixed while the tranny is in the car. Thanks Carlos

 

[TrboHead]

Could be too high of line pressure that will not allow it to drop into 1st. Do you have any pressure readings to confirm? Did you put in a new pump or PR valve? Try cruising it down the road a few minutes to get the fluid hot and see what happens.

 

[chris718]

if the builder has installed a trans go kit ther is a plug they put in the spacer plate that causes this problem when used with gn and other valve bodies . i have seen this vmany times.pullout the 2ndf exhaust cup plug on the valve body this helps too.it comes out w/out removing the valve body .if not change the seperator plate .if you shut the car off or put it in neutral and then to drive and your now really in first this should be the problem. call us 4 a plate or goto gm and ask 4 part #8657309www.ckperformance