Vibration After Installing 1 Inch Rear Block

[pcemsmedic]

I recently installed a cheap 1 inch block in the rear of my 2010 chevrolet 4x4. I stacked this block on top of the factory block. I have a vibration now. Also the u-bolts are round instead of square. Everything is tight. I know it is best not to stack blocks. My question is this: Is my pinion angle off causing the vibration? Would there be a big difference in buying the ready lift tapered block and installing it? Mine is still tapered because of the factory block left in. Any suggestions?

Thanks

[MS3DALE]

I did the same exact thing as you,installed 1" lift blocks on top of the factory ones,and no issues with mine,I also installed new longer U-bolts.

[oldschool327]

How in the world did you get round U-bolts to work? Should be square....That might be where your vib issue is coming from. I too installed 1 inch blocks on top of factory with no issues ever. Did switch them out eventually though to 2".

[kdixer]

Can you tell where the vibration is coming from? Where do you feel it the most, steering wheel, floorboard, etc?

 

If you suspect the block you could load something to sag the suspension by 1" and drive around. Are you absolutely sure everything is installed correctly? Are the factory blocks angled correctly with yoke pointed slightly upward?

[pcemsmedic]

I did not move the factory blocks so they are correct. Only thing I did was jack up truck enough to put 1 inch aluminum block in on top of factory block. Would that mess with the pinion angle since factory block is tapered? Vibration is almost constant, especially at low speeds. Feels like a driveline vibration. Real fine vibration, can feel in steering wheel and seats and all over. Do you think the round u bolts are the problem? They fit in that little sqare holder. I can change that though.

[Metro12]

Put it back like it was, and see if it goes away.

 

All these problems with people lifting their trucks, I really don't know why people risk it.

[08SierraCC]

WOW... STOP!!!!!!!! Dont even drive it... You have the WRONG U-bolts. Our trucks use square bolts . You need that full contact area of that plate and the flat part of the square bolt to torque it down correctly. Running those Ubolt can be dangerous, and is more then likely the source of your problem. The flat part runs along a channel on the flat plate on the top of the leaf springs to help align the rearend. Replace them with the correct square bolts and torque them down to about 80 ft/lbs (don't quote me on the torque spec). I was running a 3inch square aluminum lift block with no vibration. I now run 2.5 tapered cast iron blocks. I thought the rear was to high and plus I didnt trust 3 inch aluminum blocks(they were'nt soild) so i bought heavy duty 2.5 inch cast iron blocks