scoobdj01

I am new to trucks/ chevys in general, so I may not know all the terms, but willing to learn. I got this truck from a friend and it lost all forwards gear, only has reverse. It shifts into reverse pretty hard, so my first instinct is to pull the pan and look at the tranny fluid - its clean. So guess I am trying to figure out what other problems it could be ? I have searched but seems I can only find the opposite problem (no reverse, but has forwards gears). I have tried shifting it manually into the forward gears and nothing.

Any ideas/ suggestions would be great

gotstylez

you need a rebuild!.. or get a trans from a junkyard

scoobdj01

forgot to mention -- its a 1990 GMC 1500 4x4, Ext. Cab. The transmission was used that was put it but the guy said it was rebuilt (a close friend). Also used the torque converter that came with the transmission (not the one that came with the truck).

scoobdj01

I was afraid that would be the option, any idea how you lose all the forwards gear but manage to keep reverse ?

bsballfn172

I think it's weird. I've always heard that reverse is normally the first go, but never the opposite... Is it a manual or auto trans?

gotstylez

yep true. reverse is always first to go

nauticstar87

Pretty sure the trans is shot... But with the truck off. and the parking brake on, have someone shift it and look under the truck at the linkage on the trans, it could be binding. Happened to my buddys 69 GMC.

scoobdj01

I tried that after doing the filter change and its shifting fine into gear, just not engaging inside the transmission. Do you think the Torque converter is still good or could that be damaged ? Trying to figure out if I should replace it as well since I have to do the transmission.

nauticstar87

Replace the torque converter whether you rebuild your trans or get a new one. If your fluid was shot, you'll never get all the old fluid out of the TC.

kaliz

its kind of sad that no one on here has any real transmission experience. if you get a ATSG manual on 700R4's or 4L60's. it has a section that lists conditions, inspect components and for causes. It clearly states No Drive in Drive Range condition. inspect component- torque converter, for cause - stator roller clutch not holding. converter not bolted to flex plate. and no reverse isn't the first to go on a 700R4,4l60.4l60E family its generally the 3-4 clutch pack. then if you continue to drive it will burn out the 2-4 band then finally low- reverse clutch pack at the very back bottom of the case.
second clue was he said that it was suppose to have been rebuilt but reused the old torque converter. I've rebuilt around thirty plus 700R4's, 4L60's (700R4's)(new designation), 4L60E(electronic). and truly is it rare that the reverse clutch pack is ever burnt up. except for mileage they generally look to be in good shape almost re useable. the one's that actually go in the reverse drum. along with the overrun clutch plates, and sometimes the forward clutch plates in the input housing assembly they generally look pretty good too. you might want to buy a ATSG manual it list several conditions and most likely causes.