I have a '86 iroc with a swapped 350 and a 700r4 auto trans in it. When I shift from park to drive it jerks itself hard into drive after that it shifts through the gears no problem smooth as can be. What could it be and how to fix it?

 

Trans mount could be bad,just had my car on a lift for inspection and the mount has a lot of play in it,that will be next on the list to replace.

It bangs pretty hard into gear too.

 

^^ +1, I've had this problem a couple times, its always been my trans mount.

 

My car does this too! In reverse or OD, 1st and 2nd are smooth as well as normal driving, I always thought it could be the shift cable needing adjustment but the tranny mounts is definitely something to consider, My grandpa's 91' Silverado 2500 also does this too it has 250/xxx miles, nothing has blown up yet!

 

So how do I go about fixing this?

 

crawl under the car and inspect your trans mount, if it's rotted out or non-existent then you replace it.

Might want to check your U-Joints if this problem has been going on for a while, it can't have been good on them.

 

I know if you dont have the low/reverse check ball in the capsule it will slam into gear, and how is the idle set cause if its not adjusted like to high it will slam into gear.

 

As soon as I get a chance I'll crawl under and check it out, thanks