what degree of shims?

[audie.a]

I have a 93 bronco with a 8'' lift..does anyone know if im suppost to add a shim to the stock one on the rear ..i have a slight vibration..it has a rancho 4'' leaf then the stock 7 degree shim and a 3 3/4 block..the vibration is between 30 and 40 mph..i have almost tried everything to get rid of it,but cant seem to do it....any suggestions..anything would help..............

 

[Justshootme84]

Simple fix is to check the angle of the driveshaft to the pinion yoke on the rear axle. IT should be zero degrees, or straight in. If this is the case and you still have the vibration, you may have enough "axle wrap" with those blocks to throw this angle off. Other causes would be an out-of-balance tire, or the rear driveshaft, either a bad u-joint, the double-cardan joint or slip joint binding on you.

 

[audie.a]

Simple fix is to check the angle of the driveshaft to the pinion yoke on the rear axle. IT should be zero degrees, or straight in. If this is the case and you still have the vibration, you may have enough "axle wrap" with those blocks to throw this angle off. Other causes would be an out-of-balance tire, or the rear driveshaft, either a bad u-joint, the double-cardan joint or slip joint binding on you.

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i have had the rear end apart trying different shims and degrees about 8 times, and as far as the axle wrap it had the same vibration when it only had the 4'' rancho lift with no blocks.i have had the tires checked and put a different driveshaft on it(from my buddies 93 bronco) and it still continues to vibrate i dont know what else to do!!!!!!!!!

 

[Justshootme84]

Sounds like the ds-pinion angle thing is O.K., then? Next thing I'd try is to lower the transfer case an inch or so. I had todo that with a Rancho kit on a truck. It had the spacers in the kit, and I needed them to reduce the ds angle to the t-case.

 

[audie.a]

I have already lowered it 1 1/2 inches so i still dont know,and i had new gears and a locker put in it about 3 years ago and i just delt with the vibration but now its just mostly ******* me off. :angry:

 

[Justshootme84]

Wow, I've come up with about evrything I could think of that might cause this problem, it must be something internal in the rear axle or drivetrain. Maybe someone else has an answer for you.

 

[audie.a]

thank you for your suggestions..i really appreciate it..if you think of anything else PLEASE let me know.....