4l80e

[Wrecker]

I picked up a 92 3500 dually with a dump bed for a song on ebay. The tranny was supposed to be bad but when I got the truck fired up, it is drivable. It slips a little mainly in reverse and doesn't shift firmly at all but does catch all gears. I don't want to drive it any more before changing the fluid, etc. Any advice would be great. Is it toast or can it be possibly made to last a little longer? Stuff like boost valve, special fluid, or other tricks is what I'm looking for. If all sounds like a waste of time, that would be good to know as well.

 

[oneluckypops]

I picked up a 92 3500 dually with a dump bed for a song on ebay. The tranny was supposed to be bad but when I got the truck fired up, it is drivable. It slips a little mainly in reverse and doesn't shift firmly at all but does catch all gears. I don't want to drive it any more before changing the fluid, etc. Any advice would be great. Is it toast or can it be possibly made to last a little longer? Stuff like boost valve, special fluid, or other tricks is what I'm looking for. If all sounds like a waste of time, that would be good to know as well.

Sounds like you have a low pressure issue. Changing the fluid will most likely NOT help it, actually it may hurt it. The fluid that is in it now is thicker then what new fluid will be which would decrease the pressure and could very well make it not even engage in any gear.

The 4L80E is a dam good transmission, I would NOT reccomend rebuilding it yourself UNLESS you have prior Transmission exsperience. But it does sound like it needs to be rebuilt.

Also if it is a low pressure issue, then changing the pressures with out rebuilding will cause it to go completely out even faster.

If you do decide to rebuild it yourself then do your research on updates for it before you buy anything.

 

[Wrecker]

Thanks Luke. I'm not doing any more than pulling it and reinstalling it when the time comes. I have a guy who's pretty good, just kind of pricey. Will running it as is hurt it badly? Like damaging expensive parts-or am I just going to burn up already toasted parts? I'd like to use the truck and won't have any extra cash till January. My limited knowledge says I might ruin the sungear but on the 4l60e that is a part that gets upgraded I think. I don't know for sure on the 4l80e.

 

[HotRodPC]

I don't know as much about 4L80-e as Luke does, but if its anything like most other auto transmissions, you're not likley to tear up any hard parts. Before you get the oppurtunity to tear up anything else, you'd overheat the clutch packs and they'd burn up in short order. I wouldn't expect much use of the transmission.