New HD Leafs, Vibrations

[Supervillainmc]

Recently I changed the leafs in my 87 K5 Front and back. The front were 3 leafs, I put 4, the rear were 6, I put 8. I started getting heavy vibrations. I put in a Cv shaft in Rear, Front already had one, and I added 4 degree shims. For most part the vibrations are gone except at low speeds in 2 nd gear. Is there any way to get rid of these slight vibrations? The truck went up about 2-2.5 inches. Do I need to drop the T Case? Any help with be appreciated. Thx

 

[Blue85]

Start by measuring the angles of the axle pinion and the T-case output. Anything else is guessing.

 

[Supervillainmc]

Start by measuring the angles of the axle pinion and the T-case output. Anything else is guessing.

I got 10 degrees at front drive shaft and 20 at the rear. The rear T case is 12 degrees

 

[rampage]

I got 10 degrees at front drive shaft and 20 at the rear. The rear T case is 12 degrees

12* seems kinda steep. You sure you’re on level ground and your crossmember spacers are in the correct place?

 

[Supervillainmc]

12* seems kinda steep. You sure you’re on level ground and your crossmember spacers are in the correct place?

It might of been Partly on the curb . Dang.! I also think I didn’t do it right. I’m gonna check it again. Thank U

 

[ZooMad75]

With a cv shaft on the rear, the shaft angle should match the pinion angle. I had to use 8 degree shims to pull mine up to match the shaft.

 

[Blue85]

Assuming you're going down the road in 2WD and hubs unlocked, the front driveshaft angle doesn't matter. The most important numbers are t-case output angle and AXLE PINION ANGLE. Now that you have a CV shaft, the rear pinion angle should be a degree or two lower than the driveshaft angle. Measurements must be at static ride height.


So many threads here to search......

Where did you get the CV shaft from?

 

[sweetk30]

yep the guys over at offroad design helped me set up a c/v rear shaft on a lifted blazer .

the pinion on a c/v shaft needs to be pointed at the t-case or 1* - 2* max down to allow for pinion up rotation under heavy power / soft spring applications .

when i got it the blazer drove smooth with 37" mud tires at 90mph on a highway test drive .