6L80E Won't go into forward gears-Reverse is fine

[First c10]

Hello all,
my sons 1970 has a 2011 5.3 Aluminum LC9 with a 6L80E transmission.
he backed it out of the shop and put it in drive and nothing but a small roll forward.

After a little research on the ole' interwebs I found that the 6L80E has a problem with a plastic check ball in the valve body shrinks and gets stuck in the plate.
I will be checking codes later today to see if there is anything like the below explanation.

Has anyone had this problem on here? I figured I would start a repair thread on this issue....any help is appreciated.


From www.trucktransdiag.com---
Complaint: Transmission slips in forward range, first gear take off. P2723 P2728
Cause: Possible codes P2723 Sol 5 stuck off or P2728 Sol 5 performance, Very possible that the number one check ball in the valve body has shrunken and wont seal or is missing. This ball can be replaced with the 1/4 inch Chrysler check ball from a 47RE or 48RE etc part #
52118261 this ball is much more durable and wont shrink or disappear.