i recently put on some shackles my friend made for me. fronts are about 5 inches longer than stock, and rear is about 3 inches longer. after putting them on, i went for a test drive. when i put the truck in 4 wheel drive, and started to move, the engine (or something under the truck) started to grind. i immediately took it out of 4 wheel drive, and stopped driving it. my friend had a driveline spacer that he said might help, so i put that on. the grinding stopped, but now the truck vibrates like crazy from 10 MPH and up. ive been too scared of damaging anything to go faster than 20, so i dont know if the vibe stops. please help! i didnt think that a small lift like that could mess up the angle so much. what can i do to fix this?

 

u need to see what angle the drive shafts are at and if they might be binding when spinning, jack up rear on to jack stands and put it in gear, and let the tire spin for a min and look to see what the axles are doing. of course have someone in the driver seat just in case its too much bouncing and it comes off the stands, but ur angle might be too much.

 

What can I do to fix it if the angle is wrong?

 

5" longer than stock up front sounds too long IMO. 5" would have given you 2.5" lift..
Post pics.
Way to get it to stop vibrating= put the stock ones back on for now.