Anyone with 89 K5 and 4" Lift

[caleb22]

I have a 89 K5 with 4" TC springs, ORD shackle flip in rear, SX8000 shocks, and a 10 degree shim. When we did the lift the pinion angle difference was about 10 degrees.

I still get a bad vibration from the drive shaft in the rear above 20mph, and especially when decelerating. I wanted to know from anyone who may have done the same type of lift combo what degree shim they used and if they did anything different.

Just gathering info before we dive deeper.

 

[sandawgk5]

I have an 87 with 4" DIY flip in rear and my pinion is almost directly at my tcase. I did not shim at all but by calculations I need a 8 or 10deg shim. I do not have any vibes at all unless I coast. I am also running the stock driveshaft.

I also flipped the brackets and run 56s in the rear.

Ira

 

[tiger9297]

I have a '90 K5 w/ 4" lift and mine vibrated too. I orderd a new shaft w/ CV joint from Rye Valley Oil and Gear. They came highly recommended. Mine has no vibration now at any speed.

 

[caleb22]

I took it all apart today and tried a 6 degree shim, still has vibrations at 20mph and higher, and under deceleration. I also put in new HD ujoints today as well.

 

[88Silverado]

If you havent already you can try dropping the rear of the transfer case down. Pretty easy just to try to see if the vibe goes away. It worked for my 88

 

[NEK5]

i have 4 inch too and no vibrations