4t6o slipping in first gear

[61lesabre]

I have a 95 GP that threw a rod so i swapped with an 01 Montana 3400. I switch the intakes & plenum over, all the sensors look pretty interchangeable. Now the car needs to be revved before it will move. Reverse is fine, manually shifting into 2nd, 3rd, 1st don't change it, the 2nd spd start button does not affect it and I unplugged the traction controll (ABS PUMP) just to rule out a brake issue. On the road when i go thru the other gears it works fine. Any help would be greatly appreciated, this car is making me CRAZY(ER). brian

[gpse3400]

just to make sure , youf fluid level is normal?

[61lesabre]

95 gp won't shift

yes fluid is normal, and i just bought an atsg tranny kit. I'm going to try the line pressure tests when i find someone who has a guage.

[gpse3400]

You can check the forward servo on the back side of the transmission. You have an H-body I assume, it will be very easy to get to. Check for a craked piston or a bad seal. 3 8mm screws and its off.

[61lesabre]

4t60 slipping

That nasty 4t60e TCC clutch fuse strikes again! I checked the fuse (somebody borrowed it) upon replacement the tranny is working fine. Had this in 1 other car. Who would think to check for fuses?