4L80E No Forward Gears But Strong Reverse?!?! Help

[MATTJ]

Ok I have a 2000 cclb dually 454 that i bought last year without a engine for cheap. I put a engine in and have been doing odds and ends trying to get it ready to be on the road. Its been sitting for about 10 years pryor. I rebuilt the back brakes and bearing and seals and pulled out of the shop and turned it around and nosed back in to redo the fronts. When i finished up truck backed out fine but now has no forward gears unless you rev to moon. Reverse will spin the tires still. Fluid is full and clean. If anyone can shed some light on this for me it would sure be appreciated. It did drive fine after I put the engine in. Matt

 

[andy396]

Sounds like the Forward Clutch isn’t working properly.

 

[MATTJ]

Sounds like the Forward Clutch isn’t working properly.

But would it just "give up" setting there? Just seemed like possible electrical issue internal to me? I could see possible mechanical failure if i was driving but this was a working then turn key off then start back up and nothing type of thing.

 

[andy396]

I’m pretty sure the forward clutch is mechanically applied only, so as long as there’s pressure and the valve position sends fluid its way it gets applied for all forward gears. Might want to check fluid pressure. Did you have the torque converter off? If so, any chance you didn’t get it installed all the way? If that happens it’ll ruin the pump gears. Since you have reverse it sounds like you have pressure so I highly suspect the forward clutch is shot. No, it’s not typically something that goes bad while sitting, but if they were about shot when parked and the fluid level was low maybe that did it in?

 

[MATTJ]

Ok thanks for the help, I'll try to get some pressure readings and go from there.

 

[Sam Cooper]

If you unplug the communication cable from the transmission, it should be in second gear. That shouldn't require the torque convertor to stall up.