axle shims needed after 2" lift using blocks and crank???

[BOTTLEDZ28]

I have a 98 2 door hoe 4x4 and I installed 2" rear lift blocks along with cranking the TB to level it. The blocks were not angled. I have been getting this "thump" feeling in the truck as soon as I take off from a stop. It almost feeling like something is moving in the driveline but I cannot see anything wrong. I was thinking that maybe I need to install some axle shims to get my pinion angle back to where it used to be. Can anyone tell me if axle shims are needed on a 2dr with 2" rear blocks? The 2doors are the worst for pinion angles due to the short wheel base.

For the record, this "thump" feeling didnt start until a few months after the "lift".

 

[slippy3002]

I have a 98 2 door hoe 4x4 and I installed 2" rear lift blocks along with cranking the TB to level it. The blocks were not angled. I have been getting this "thump" feeling in the truck as soon as I take off from a stop. It almost feeling like something is moving in the driveline but I cannot see anything wrong. I was thinking that maybe I need to install some axle shims to get my pinion angle back to where it used to be. Can anyone tell me if axle shims are needed on a 2dr with 2" rear blocks? The 2doors are the worst for pinion angles due to the short wheel base.

For the record, this "thump" feeling didnt start until a few months after the "lift".

That is called axle wrap. Yes, you are gonna need 3*-4* shims. Blocks you buy are 3* so giving the extra space for the shim I would go with 4*.

Sent from ®obland

 

[BOTTLEDZ28]

Thank you. I will look into this today. Any negative side effects to axle wrap over a long period of time?

 

[bow61509]

Another thing to take into consideration since the problem didn't surface until a couple months after the block installation. Did you make sure to re tighten everything? It's recommended after doing any install like that to retorque everything after a couple hundred miles. IMO you wouldn't feel axle wrap and probably wouldn't have much with only a two inch block, there's people running taller blocks without much issue. A bad pinion angle will cause a steady vibration as your driving. I would seriously bet your u bolts are a bit loose, and have just enough play to cause a noise when they move around a tiny bit. And you won't notice any of that with just a visual inspection with the weight of the truck on them.

Sent from the big block!

 

[slippy3002]

Thank you. I will look into this today. Any negative side effects to axle wrap over a long period of time?

Not sure, but it's literally bending the springs each time. I imagine it would just make them fatigue faster, hurry bushings, and possibly hurt the u-joint.

Sent from ®obland

 

[slippy3002]

Good point Dean! I didn't think of that.

Sent from ®obland

 

[BOTTLEDZ28]

Do you guys know if its possible to just replace the 2" rectangular blocks with 2" angled blocks? I only ask because I dont know how safe it is to add the blocks and then jam in some beveled piece of steel between the block and leaf spring.

 

[slippy3002]

Do you guys know if its possible to just replace the 2" rectangular blocks with 2" angled blocks? I only ask because I dont know how safe it is to add the blocks and then jam in some beveled piece of steel between the block and leaf spring.

Why not? You can put angle blocks in it. People have also been shimming blocks for decades.

Sent from ®obland

 

[SCOTTYINWV]

Details on these angled blocks and or shims?

 

[great white]

....Any negative side effects to axle wrap over a long period of time?

Yeah, broken spring pack leaves.