Tahoe Won't Shift Out Of First

[Thebert]

I just replaced my broken 4l60e on my 97 Tahoe with a 4l60e with far fewer miles but I cannot get it to shift out of 1st. It won't shift out of 1st in D, 3 or 2. At first the speedo didn't work. I know problems with the VSS can cause shifting problems so I swapped out the VSS from the origianl tranny, which I knew worked, and the speedo now works fine. I broke the original neutral safety switch taking it off the original, so I installed a new one and had some troubles with the throttle position connection plug but have cleared that up as well. My other thought is that the "new" tranny may actually be a 98, the original was a 97. The guy I got it from said that it was a 97, but a label on it seemed to indicate a 98. If they are different years do I need to get it tuned? Are the PCM and tranny not communicating? Any ideas would be helpful.

[DofD]

Hi there and welcome to GM Trucks!

 

I wish I had a suggestion for you, but what it's way beyond my experience.

 

Does the new tranny shift to neutral or reverse?

[sonjaab]

If your Ho' is a gmt-400 you should check the fuses.

IIRC if the odo/speedo fuse (#15?) is popped your

speedo/odo won't work and your trans will NOT shift

and stay in 2nd. Reverse will also work.

[Draenor]

If your Ho' is a gmt-400 you should check the fuses.

IIRC if the odo/speedo fuse (#15?) is popped your

speedo/odo won't work and your trans will NOT shift

and stay in 2nd. Reverse will also work.

IIRC, should be a 10A fuse(red).

Also double check all connections. As for the year, you should be fine. Once you get it back on the road the transmission may need to learn its shifting characteristics. Don't be worried if it shifts funny for a bit.

[Thebert]

(DofD posted today Nov 8 2008, 12:50am)

Hi there and welcome to GM Trucks!

 

I wish I had a suggestion for you, but what it's way beyond my experience.

 

Does the new tranny shift to neutral or reverse?

 

Thanks for the welcome. It does shift into neutral and reverse. It shifts into all forward gears (D, 3, 2, 1) but is has not and will not shift out of first.

 

 

 

QUOTE (sonjaab @ Nov 8 2008, 01:52 AM) If your Ho' is a gmt-400 you should check the fuses.

IIRC if the odo/speedo fuse (#15?) is popped your

speedo/odo won't work and your trans will NOT shift

and stay in 2nd. Reverse will also work.

 

QUOTE (Draenor @ Nov 8 2008, 07:44 AM)

IIRC, should be a 10A fuse(red).

Also double check all connections. As for the year, you should be fine. Once you get it back on the road the transmission may need to learn its shifting characteristics. Don't be worried if it shifts funny for a bit.

 

I checked all the connections and the fuses are all fine. I found that the fluid was overfilled and was foaming. I drained it and will get it back to the correct level once I run it. Overfilling shouldn't cause it to not shift should it?

 

I also disconnected the battery for a while. Hopefully a "clean slate" will help. Even if it is still learning to shift, shouldn't it shift at some point?

 

Let me know if anyonne thinks I missed something!