I has backing up in a parking lot today and my truck made a bang noise. Now, I have no reverse, 3rd or 4th gears.

auto or manual? either way bang is not a good noise.

Possibly a cracked sprag, or one way, clutch ring.

It is a 4L80E auto. I didn't realize anything was really wrong till I got out of town. (While trying to stay ahead of traffic I found out my engine will go to 3900 RPM)Edited by: whatnot

I don't know how the gears line up inside the 4L80E. Is it possible to have a mechanical failure and loose 3rd 4th and R and still drive home in 2nd? My alt went out one day and I was driving and when I slowed down it never shifted higher again because lack of electrical signal, I guess. I drove home 20 miles like that.

Something is definately broken inside. When I rev it up while it is in reverse, I can hear noise coming from the transmission when I let up on the pedal.


About how is a used or rebuilt one going to cost me? How hard is it to change? If it is going to take too long, I might take it somewhere to get it done because I haven't had much spare time lately.

Probably best to let someone else do a tranny. Unless you like that kind of work. It's going to cost either way. Always best to call around and see who can do it and for what.


Personally, I'd try to get a fresh salvage for a few hundred from a relativly low mile vehicle, if possible, and if I rebuilt, it would be with a HD clutch pack and perhaps the B&M valve.

Really sounds like a cracked sprag, part of a planetary gearset on a clutch drum hub.


But, if you drop the pan, check the 3-4 solenoid, compare resistance reading to the others in the 'pack'.


If it is open, replace it and try again, dependiing on volume of metal and composition clutch material in pan, and odor and color of fluid. Edited by: gmctd

If it is a cracked sprag, can it be replaced without pulling the transmission?

I don't think so.


http://www.dieselplace.com/forum/uploads/quantummechanic/2004-11-19_150229_4l80.jpg


www.sallee-chevrolet.com/ChevyTransmissions/4L80E.html (http://www.sallee-chevrolet.com/ChevyTransmissions/4L80E.html)

No - requires removing the pump\stator shaft, input shaft, and etc.


4rth-o\d planetary is right behind pump - only engine\TC\pump\input shaft reduce speed when in o\d.


From there back, it's a T400 with electric valve body..........Edited by: gmctd

What years of transmissions will work?
I just looked at car-parts.com and they have 1995 all by itself and 1996 by itself then 1997-1999 together. Can I use one from a newer truck?

i don't know about changes between '95 and '99 but my manual says that the pre '94 4l80e was quite a bit different including a different force motor and some different electronics as the pre '94s had a tps on linkage and the later ones are drive by wire. so i'm not sure about the ranges you specified but i do know to avoid anythig before '94. safest bet would be the '95 unless others know of some improvements to the newer ones that may help.gud luk

I found a transmission on ebay that looks pretty good but it is in Brighton, Colorado.
I don't suppose anyone will be driving from Colorado to/thru Wisconsin this weekend?
If anyone is, I will pay for their fuel if they want to haul it (and I win the auction).

If anyone is interested or know of someone that is, please send me a PM.

What are you looking at paying? I'm still calling around here trying to find a low mile 4L80E for under $300.

I am guessing it will be over $300 but hopefully not much.

If anyone is still interested in what is happening, I think I am going to get a transmission from the place that sells them on ebay. (Roadmaster transmission)
They do come with a torque converter.
The only thing I don't like is that they will only give a 6 moth 6,000 mile warrantee unless I get the HD version with RV converter ($700 extra or $385 extra for just the RV converter) because it is going behind a diesel.

I called them and they are the same price for 4x4.

I have a local transmission shop checking on prices now but he didn't think he could get a better deal.

I was going to have a chevy dealer fix it but they wanted $650 just to remove and replace it. (should have been $500 max acording to dmaxallitech. (they have a $65 per hour rate) They checked it out and said the direct clutch is burnt up.

A transmission shop said he would do it for about $400 including fluid and cooler flushing.

Do you know the folks at the tranny shop or know if they have a good reputation, if it were my $$$ that would be the route to take if they have a good rep; if something went wrong the local shop would be easier to deal with than an internet sale.