The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - 6L80E Won't go into forward gears-Reverse is fine

**First c10** · 07-10-2017, 10:27 AM

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.

07-10-2017, 10:27 AM	#1
First c10 Registered User Join Date: Dec 2012 Location: Los Banos CA Posts: 2,705	6L80E Won't go into forward gears-Reverse is fine 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. __________________ 1956 Chevy Bel Air 2 door 1956 Chevy 210 4 Door 1970 K20 LWB project the Hulk build w/Supercharged 4.8L-ly2/4L60E HULK BUILD 1970 C10 Yellow/White Deluxe LWB w/ 5.3L-LC9/6L80E 1968 K10 LWB Dark green my son calls it "THE HULK Jr"HULK JR SOLD GO GO!!!