I just had my trans rebuilt by a shop. They took forever to do so. My trans used to shift at WOT at 6400 rpm now it shifts at 6000. If I leave it in manual first, it will automaticly shift to 2nd at 5500 rpm.

WTF did they mess up?

 

Is this a 4l60e?

 

Maybe it was slipping before and thats why it showed 6400rpm shift unless u tuned it to shift up there.

 

I can tell you that absent the transgo hd2 kit it is normal for the PCM in the 4L60E and GOVENOR PRESURE in the 700R4 to overide the manual shift and the trans will upshift to 2 while in manual low at high RPM, That would be normal.
Also on the shift points it could be as mentioned if they other trans was badly worn or if they installed a shift kit, But really need more info like model year etc,Im assuming from your user name only its and LT1 car. But more info is needed. Whats happeing may very well be normal operation.

 

1995 LT1 4l60e
Heads and Cam
PCM for less tune

I used to be able to hold manual first.

In OD ive noticed the shift points are lower too.

 

they probably did their own mods to it and changed the previous mods that gave you manual 1st......lots of guys know how to build but they dont know how to see what is already in a tranny and that is what saves me money i get trannies that have been built to the max and becuase i can tell what has already been done i dont have to spend lots of money.....there are builders and people who know how to build

 

shift points are strictly controlled by the PCM the trans can only do whats its told. If you previous trans had a transgo shift kit they may have changed the vb for what ever reason and did not likley switch the 1-2 valve over to it,

 

they prolly kept his VB becuase they knew it was a good one and his is going on someone elses tranny and he got the one that was in the pile lol

 

x2

It happens all day long.

 

Though agreed thats very possible , Its also just as likley that the valve body was badly contaminated and just replaced