motor issue PLEASE HELP!!!

[JDMSTROKER]

Can anyone tell me if they've had this problem truck has 167k miles on it just recently when it shifts at 40mph sometimes it vibrates real bad and when i give it more throttle it stops but i get small puff of black smoke but it does'nt do it all the time i am running banks kit on it any help or is it no big deal i'm not sure.I just got the truck about 2 months ago and i run amsoil fuel additive with every tank and then it started so i'm not sure if fuel deposits are comin lose an blowing out the injecters.

[Southpaw]

Are you sure it's not driveline related, and when you punch it to get it to stop the black smoke is just from getting on the throttle hard?

If it is driveline it could be a carrier bearing, u-joints, driveshaft weight, etc...

Or it could be a torque converter issue. Any other shifting/slipping issues?

Just acouple of thoughts

[dazdillenger]

where are you located? Is all your suspension stock? check your carrier bearing for play-it is the hanger bearing that is at the joint the rear driveshaft splits.

[JDMSTROKER]

I was thinking drive line but i'm not really punching it to get it to stop just nice smooth acceleration and it's gone and i would think if something in driveline would prob do it all the time appreciate the info tho still might check drivetrane.

[JDMSTROKER]

other than air ride suspension is stock i'm in Gettysburg, Pa

[Southpaw]

Vibrations in the driveline will definitely come and go at different speeds and can happen at only one certain speed.

Def. worth checking out so it can be eliminated