SSkeet

Have a built 4l60 which has been fine for a year and has held 600RWTQ. Took it out to install a new motor, a 408, and now it feels like it has a real SOFT 2-3 shift. Kinda doesnt want to go into 3rd, same for 3-4. Just kinda revs in 2nd to the top and then at the top feels like its slipping or something.

Could it be a solenoid or what? Tranny fluid looks and smells fresh. No sign of anything burnt.

Tranny is vacuum modulated

SSkeet

I just remember too...1-2 shift used to be VERY HARD and now it seems to be kinda soft....

bigbadblackws6

iTrader: (1)

how much hp u have running to your car and what kind of mods do u have? i am wondering b/c i am doin some stuff to my car and need to know how long i will have about till everything goes bad.

rdavis93

I had similar symptoms on mine for awhile, and now I need a rebuild. Mine wouldn't shift into 2nd eventually so I would have someone look at it ASAP and hopefully you can avoid this. I'll tell you more once mine is opened up.

SSkeet

I just read something about MAF ENDS causing my symptoms...and guess what I have on the car? lol
I will put the stock ends on tomorrow and try that...but it really seems like too much slipping to be the MAF Ends.

I dont know how it could be the clutches, as I never had a prob in the past...but we shall see...

SSkeet

OK took the MAF ends off and didnt seem to change anything as I thought...

1-2 Shift: Dead on..hard shift
2-3 Shift: gets to 5500 and seems like it comes out of gear and just revs in neutral

If I go anything under maybe 40%TPS, the tranny shifts through all gears just fine....

BLK02WS6

iTrader: (2)

MAF ends shouldn't do anything to your tranny cause you have vacuum modulation - vacuum modulation overcomes the line pressure issues that mods such as MAF ends create.

WeeWolf

iTrader: (16)

sounds internal, but check the cooler lines and make sure their not restricted because it could be lack of fluid getting back to the tranny and causing air in the system probably not the cause but it happened to a friend after a cam swap.

SSkeet

Got a PM from a guy that says he had my same problem exactly and said he then over-filled his tranny fluid and it went away completely...then he drained some to verify that was the problem, and the problem sure enough was there. Then he filled it back up a lot and problem went away...been fine for thousands of miles

I will try putting some more fluid in tomorrow, but the level seems to look normal...

SSkeet

OK solved the problem...AND THIS IS REALLY BAD! It needed 2 quarts of fluid...not sure why, but when I did the motor swap I checked it and it was full after going through gears...but this morning I added 2 quarts and now it shifts great.

NEW Problem: Wont downshift all the time. Most times on the highway going 50-69, when I smash the pedal, it stays in 3rd and sluggishly pulls, when it should be downshifting to 2nd as normal...
Could it be torque management? I am afraid to disable it because last time I disabled it, I broke my kevlar band that day...it snapped in half...
Cant think of what else it could be

SSkeet

New problem solved...after the new motor install, somehow the throttle cable was out of whack and it was reading max 84% TPS. So fixed that, and now it downshifts as it should...