c20rj

I just broke down a 4l60e that i bought off of craigslist. This trans was out of a 05 silverado with 50 miles on it, as the story goes from the guy I bought it from. It was removed from a new truck that leaked trans fluid from the pump area on the drive home from the dealer, customer pissed off, saturday= no parts, so they removed a trans from another new truck, customer leaves happy. This trans was basically a core, but looked new, and was 200.00 so I took a gamble and bought it. I figured I should upgrade the band, anchor pin, servo and three-four clutches for my 73 nova build so I tore it all the way down and everything inside is perfect, nice fresh red fluid, no sediment, flawless. Upon inspection for the cause of the leak I noticed that the front pump has no groove for a case to pump o ring. The only thing there is the gasket between the pump and case, but nothing to seal the o.d of the pump to case, w.t.f? Is there a new seal design and it is missing or is it missing the machined groove? Does anyone have experiance with these late model 4l60's? Thanks!

Jays_SSZ28

iTrader: (2)

It's a big metal clad seal. Heres a picture from this thread.

Attachment 670110

c20rj

Thank you for the response, and the link! It has been a few years since I have done a 60, I knew something didnt look right, as there is absolutely no evidence of that seal ever being there. I hope this was the only problem. I guess I will find out soon enough, I usally pay a local tranny guy to dyno my work, he has a pretty cool homemade fixture with a sbc on it, and he only charges 75 bucks to do it.

FLT

iTrader: (1)

Make sure to look closely at the case and pump area where that seal sits. I have seen the slightest little buggers or gouges cause those seals to leak. Good luck with the build. Vince