Hard Drive to Park shift

[K20Submarine]

Hey everyone, well I just went from an 88 manual toyota tacoma to a 86 K20 Suburban, its been a long time since Ive driven an automatic, now Ive got the truck sitting waiting for some minor maintenance when I get the money. Now here's one of the issues I want to address, when I shift the truck from Park to Drive I can feel the truck pull pretty hard, and I guess the best way to describe it is that it "bumps" into gear. There's a slightly loud pop and then I can feel the truck pulling if I let off the brake. Now going from a manual 4 banger to this beast is a whole other world so I just want to know if this is normal? Or if there are some things I should check? Thanks guys and Ive got some more questions for later on but this is top of the list right now.

[OrangeAnimal]

First thing is to check the idle speed. Next I would check the driveshaft and u joints. Then check the transmission mount and then the engine mounts. My guess is it will be a combination of these causing your issue.

When you check the mounts make sure they are bolted tight to the trans and the cross member. Same goes for the engine mounts. I usually use a pry bar and try to move the engine or trans in any direction. It it moves then you know you have a problem. Good luck. Keep us posted.

[K20Submarine]

Alright so weather permitted I was able to go outside and check the mounts and most of the drive train for play. I couldn't really find anything that moved around a lot, the tranny mounts moved slightly but they are large black rubber things that look like they are intended to take a little shock. Now heres what I found shifting the truck with a little special touch. When I shift from Park to Drive and I do it quickly and not stomping on the brake the shift is pretty clean no thumps or jerks, but if I hold the brake pedal to the floor the shifting is much harder, can anyone make any sense of this? Thanks for quick reply earlier Orange.