4L80e issues!

[AJII]

Hey guys,

Need some help.

4l80e in my truck is acting strange. If the gear selector is in the OD position, after a short time (1-2 miles or sometimes sooner) it'll lose all gears and just freewheel/clunk. But if the selector is in the D position all is fine.

Converter is fine, locks up great, doesn't slip. And 4th gear is fine too until it loses all forward momentum. Any ideas?

 

[77K20MT]

Probably not what you wanna hear, but it sounds to me like the Over run sprag is going out. That is the first one way clutch in that trans. It also has a clutch pack around it that holds for engine braking in the other ranges like D,2,1. So when it stops moving in OD and you place it in D that clutch pack comes on and you start moving again.

The trans will most likely need removed and repair/rebuild. Unless somebody knows of anything else. I have worked on 4l80e's and that is what it sounds like to me.

 

[AJII]

Thanks. That's exactly what it sounds like. Crap

The whole point of the 80e swap was longevity...so much for that!