Question : Trans slams into Drive after 3.4/3.5 swap

[01oldsalero]

2001 alero went from a 2001 3.4 to to a 2005 3.5. Engine runs great but it slams into drive. Reverse is fine but when I put it into drive it jars the whole car. Does anyone have anything similar that they've run into? I didn't have this problem prior to the swap. I'm wonder if it may have something to do with a sensor or something I may have missed. I really have know clue.

[3XTurboAgain]

loose lower or upper motor mounts or tranny mount? just a guess

[geldartb]

is your mass air flow sensor plugged in.
that would make it slam into gear.

[gpse3400]

I agree with Geldartb. I would also add that there might be a tuning issue...I dont have my book with me so I can tell you with any certainty.

[geldartb]

i know with the grand am/ aleros when you unplug the maf sensor it for some reason jacks up the tranny line pressure to the max.

found that out when i was doing my tune.

[IsaacHayes]

yeah sounds like MAF is messed up or not plugged in.

[sanjay]

Is your idle higher than normal?? When it's really cold out here the fast idle is close or higher than torque converter stall point causing it to slam into gear until it warms up. I know it's not cold out but temperature aside you may have the same issue.

[geldartb]

when my car was stock and it was cold out for a little bit it would idle around 1100-1200 but once it warmed up it was under a 1k

id still try a different maf sensor. it could be bad or something but those sound like the symptoms of a dead or dying maf sensor