4l60 issues! Head scratcher
 

Ok so got a head scratcher here...

I just bought this 93 Chevy c1500 with a 5.7 4l60 e tranny.

The motor has a vortec bottom end and a Tbi upper with Tbi heads. Got the truck dirt cheap since the trans was out (didn't have 3rd or 4th gear) and everything was pieced together out of junkyard parts. Had hell getting the timing and idle correct due to it being a Frankenstein motor. He had the trans cooler lines bypassed to each other due to bad radiator leaking internally(thinking that's why trans went out in the first place. ) needless to say I replaced the radiator.

Being in a hurry... I Bought a used trans from a company called bolt on, they supposedly have a trans guy go through it and make sure nothing is broke internally. When installing found that the 1-2 3-4 solenoids were broke, looks like its been hot (internal plastic wire holders were crumbling), the pan was too shallow, and did not have a reluctor ring on output shaft. Bought a new reluctor ring and used the pan and solinoids off of the old tranny. Then trans worked great. Shifted normal, pulled strong. Drove it about two days then I lost 3rd and 4th gear again.

I noticed on the shift solinoids I installed, the o rings were worn and the unit didn't fit very snug. So I replaced them with new bwd shift solinoids. Still nothing.

I know... prob the 3-4 clutch pack is toast but I wanna make sure it's not something else I'm not thinking of before I go tearing the trans apart. Just seems like too much of a coincidence that I bought a tranny with the exact same prob as the one I'm replacing. And how suddenly I lost the gears. In my experience a gear may slip for a while before it goes completely out. . Or if something is causing more strain on the 3-4 gears. Maybe computer issue? Rear end? Or just my bad luck...wouldnt be too surprised

Thanks for joining, B-fast! Glad to have you as a part of our community :)