chip causing transmission failure?

[nopower65]

I just lost the transmission in my 95 Suburban, after about 2 weeks with a chip. The chip took several iterations, since earlier chips wouldn't allow the transmission to shift.

had a new tranny installed, it burnt up within 150 miles of leaving the shop.

Anyone have experience with chips or any transmission related issues? Should a 4L80E be failing in a 6.5?

any input welcomed.

[JohnHolt]

I have a Kennedy chip in my 94 and no problem.
I also rebuilt this transmission myself.

[charliepeterson]

These are very good transmissions.
Did the new transmission go in with an inline filter comming from the cooler? This will catch any debris left over from the old transmission.
Did it shift ok during the 150 miles? Maybe a solenoid is just hung up or one of the speed sensors failed.

[nopower65]

The chip was from Heath, the tranny was a 4L80E. There had been no problems whatsoever prior to the chip related issues. the replacement tranny was a *new* unit (I'm married to this 'burban until GM offers another diesel in the new burban). Was going down the highway, 65 mph- it acted like it went into neutral-- engine pegged to redline instantly. Killed motor, restarted- was fine until I stopped- then nothing at all in drive. Could manually shift it from L to 3. Got home- no R, and wouldn't move at all the next morning. No fluid loss. The installation has been quite thorough, all lines blown out, cooler flushed, etc.

[Journeydog]

Did you try replacing the Heath chip with your original? What happened then?