ACAMS

I have a 2000 GMC 1500 Z71 and about 3 months ago I had a small shop install an LQ9 6.0 for me.
Ever since they did the swap, sometimes, not always when I start my engine the truck launches like in reverse ..... it doesn't go anywhere because it is in park, but it tries to.
At first I thought the guys may not have seated the pump, because his uncle pulled my transmission years ago and I later found out he left the torque converter bolted to flywheel ..... needless to say it trashed my pump and new transmission.

Anybody seen this happen before .... truck lurching, not dummy leaving converter on flywheel?

FFDP

iTrader: (2)

Could the PRND321 shifter rod dealio down on the side of the transmission not be all the way in the park position? So when you start the truck back up it's partly in reverse but still in park?

Only a random thought I have.

terravast4

iTrader: (25)

^^^^ my guess also

ACAMS

Was kinda my only guess too, but it doesn't look moved or bent ..... I guess i will crawl back under and unhook it and check slack.

THANKS!!

haulin-c10

Check the position of the shifter. Hook up a scanner and go through your gears and look at the gauge panel and see where it's at vs the scanner.

01ssreda4

iTrader: (87)

Check the shifter as mentioned the only other thing i could think of is if the converter clutch was somehow being engaged.

ACAMS

I did have a problem with my converter clutch throwing a code and not locking up for the first couple weeks, but hasn't done it in a long time.