4L80E lost reverse

[matuva]

Good day all,

A guy told his 4L80E ( on 1996 K1500 with 6.5l) has lost reverse.

All forward an OD do work flawlessly.


From what I found in browsing the forum, it might be the pin or the band.


Does anybody have diagrams or pictures to show what is the pin or the band ? Do I have to pull out the trans to do that job?


I have never opened a 4L80E yet, and few informations before I start would be welcome



Thanks in advance

 

[NVW]

Al, this may help. http://www.scribd.com/doc/34146059/4L80E

 

[matuva]

Thanks Leo, a good point where to start

 

[THEFERMANATOR]

The reverse input drum cracking was an issue on 96- trucks due to pressure spikes.

 

[racedaymechanic]

I lost Reverse in my Truck when I first put my truck back together, there are several things that can cause that and don't require a rebuild or trans removal, the reverse Servo piston is known to breaking out the center, Mine was ok but I put the New aftermarket one in anyway But I lengthened the Servo rod .200 and it worked like a charm 25k miles of towing and its still going strong heres a good pic of the piston and the rod along with the Sonnax kit heres a link to Sonnax http://www.sonnax.com/publications/transmission/titles/reverse-drum-wear-a-4l80e-true-story