Thrdlife

So I have a 99 Z28 with a built 4l60e (I won't name who) since the person I bought the car from is a fabricator at the establishment but they are a very well known Auto Tranny Builder on here. Anyways the car makes under 400rwhp with a revmax 4200 stall. I went to see what the car would run at the track tonight and the car keeps popping out of gear it seems like and free revs until I put it frm neutral back in to drive. At first is was 2-3 shift would make it free rev (pop out of gear) but then I tried loading the converter from a stop and launching it and the car popped out of gear in first at around 3-4k rpm way before rev limiter. now it seems to do it in any gear if there is enough load or at WOT at all. I thought maybe low tranny fluid. added some more fluid, checked the levels and it still does it, Prob even worse now.

mrvedit

Are you saying the shifter actually moves from Drive to Neutral?
If true, I would suspect engine and/or trans mounts.

Thrdlife

The shifter doesn't move. It just feels like the tranny is poping into neutral

performabuilt

iTrader: (25)

I would suggest adding about a 1/2 quart of fluid and see what that does. Otherwise maybe the input sprag is letting go but description is kinda vague.

Thrdlife

Thats exactlt what i did performabuilt. It didnt get any better but now i have no third or fourth gear at all. It feels like irs barely scraping the gear and not actually engaging all the way. I am seriously considering going with performabuilt tranny though if i cant get this tranny to work. Its sad because i know it has a LOT of the good parts already in the tranny. Supposedly rated at 600rwhp

Jake's Performance

iTrader: (2)

Sounds like the 3-4 clutches have failed. Possibly a sprag issue but failed clutches could cause the PR to stick causing low pressure.

Thrdlife

its weird because it also pops out of first gear as well when the converter starts to transfer the power from the stall around 3-4k rpm

performabuilt

iTrader: (25)

Certainly sounds like a mechanical failure at this point possibly multiple.

kinglt-1

iTrader: (26)

The trans is not popping out of gear, i do not think that is possible. Low pressure with a big stall will make it "feel" like it is not in gear. I am guessing it was ran hard with not enough fluid and took the clutches out.

Jake's Performance

iTrader: (2)

It's possible to pop out of gear. Shifter cable adjustment and/or broken mounts can cause it.