Your rear band is f*cked. They wear out. Been there. :-(

 

Way to pop his balloon lol

 

Subtlety at it's best. lol

 

I'm an expert on ******* up the hardest to reach parts of an 80e. Like when I accidentally mixed year revisioned parts of the rear planetary.

"Why doesn't my truck move after this rebuild?!"..

"realization washes over and I curl up into the fetal position on my garage floor"...

 

The Reverse Band adjustment is very sensitive. I would check that first, CK performance has a good Write up somewhere.

Check to see if the Servo is cracked, that is common.
The Servo Pin can be welded on if the clearance is out of spec, and if the band isn't broke, burnt, etc, it can be fixed with out pulling the trans.

There is a way to see if the band is broken, and if its fixable without pulling the trans. Unfortunately this requires a Servo Cover modified with a bolt through the center to Manually apply the Band on. Perhaps a bolt could be wedged between cover and band with out modifying the cover. It would take some farting around but probably do-able. I want to say you have to reinstall the pan, fill it with fluid and put it in reverse and ONLY reverse, if it works, its an adjustment or hydraulic issue, not the band. Its been a few years since i had done this once, so I could be fuzzy on the exact procedure.
This is a Pain to do, but if you really don't want to pull or rebuild the trans, it could possibly work for you.

If reverse becomes weak, a guy can catch it right away and sometimes fix without frying the band and needing a full rebuild. Good luck

 

I know this is a really old thread but gotta try, customer came in years ago for tranny swap, he ordered it, had it shipped up on the barge,(we live in SE Alaska) can't remember where he got it from, but swapped the reman and installed the aftermarket trans cooler, lost reverse and only reverse while still on the lift, him being who he was didn't want to deal with it $$ just ordered another trans from same place and gave us the bad reman which we held on to, I now might be in need of it and looking for any diagnostics and or suggestions for the problem before I attempt to stab it in my free k2500 pick up...

 

The post above yours covers everything that could go wrong.

I know the pain of getting parts to AK. Thankfully I grew up in Anchorage, it could be much worse.

 

I thought I was going to be the one to bring this from the dead...whew... Anyway, trans has 20k on it or so on a Transtar rebuild kit, HD2 with Jake's recommendations from LS1tech, Sonnax boost valve, and dual fed. It was rebuilt by a GM trans tech (not saying it's perfect, just putting things in context). I swapped the converter and on the test drive, the factory line apparently wasn't secured and blew off. Lost a bunch of fluid, of course. I didn't notice there was an issue until 2000 miles later when I tried backing up a hill.

1. Gears 1-4 work
2. Dropping to 1st gear works both up to 25mph and engine braking
3. It engages in reverse, fine on small hills, but if I hit the gas, it just revs
4. Took it to a trans shop, they said I have a low pressure issue, 75psi instead of 90 at idle
5. I can sometimes hear the pump winding up when I first start it in the morning
6. I towed a 3000lb trailer just fine for 1000 miles but my converter still unlocks after a few hours of interstate driving under that load found in this thread.
https://www.performancetrucks.net/fo...towing-553197/

Gonna drop the pan this week and see if the reverse servo is cracked. Otherwise it's coming out.

Anybody have any insight? ha

Thanks in advance

 

Just had the same issue on a 99 4x4. Extented the band apply pin and now have reverse. Used the extendo pin off ebay. Left it full length. Works great. They add .300 to the pin