The drain plug that I pointed out is not a drain plug, but a level plug. Once the transmission is up to temperature you unscrew the level plug and check to see if any fluid drains out, if that's the case then there is too much fluid. If nothing drains out, you add fluid until is drips out. Same thing on the 8L90 and 10L80. Each transmission the 4L, 6L, 8L and 10L take their own unique transmission fluid.
Thanks for the great videos on this truck build. I'm putting a 6l80 in a 54 and i'm a little confused on the stock rubber mount. it looks like the center tab is wedged down against the cross member kind of defeating the purpose of the rubber mount, just wondering if that's how it is in the factory cross member or if you had any issues with it. Thanks.
The rubber mount came off the 2009 Pontiac G8 GT drivetrain, so I'd thought I'd reuse it. Regardless of how it looks, it fits really nice and provides sufficient isolation. We had to completely rebuild this tranny as all three clutches were trashed, cost 4K. Turns out 2009 is a really bad year for the 6L80. I usually only purchase 2016 and newer takeouts with less than 40K, but this was a budget build, we built the whole truck for under 15K.
