Ok so I ordered belltech 2" drop schackles, they didn't come with shims. I have seen some kits with shims some without. Do I need them?

 

Always. You need to keep the pinion at the same angle. That is why I went with the Ground Force kit. Some say that if it does not vibrate, you can go without them. I think it still puts pressure on the seal and yolk that will eventually cause a problem.

 

Wonder why the belltech one doesn't? I know groundforce does......

Contact>>> https://www.f150online.com/forums/me...547-t_s_s.html

Here's where you can get them>>> http://thesuspensionsource.mybigcomm.../Pinion-Shims/

 

Which degree do I need?

 

2 degree as I recall

 

2°………

 

thanks guys, I guess I wont be doing this afternoon since I have to order the shims now.

 

Be sure and follow the directions. Some people install the shims backwards. The fat side of the shim should point to the rear of the truck.

 

Thank you Sir..

 

Well according to Belltech I need 2.5° shims, no one around town sold them lose so I had to order a set. Guess I'll be waiting a few more days to install. Seems nothing ever goes like planned.

 

Who did you get your drop shackles from?

 

I bought the schackles from ebay, they are belltech 6406, but they don't come with the shims. So I had to buy those also. According to the dude at belltech, some kits come with them and some don't due to the fact some people don't install or want the shims

 

At least you're getting everything together before you start.....good luck!

 

Actually, it's because universal joints are not "constant velocity joints" in operation except when and only when operating in a straight line. At any angle other than straight (180 degrees), assuming the drive side is at constant steady speed, the driven side oscillates meaning it speeds up and slows down twice every revolution. It makes the same toatal number of revolutions as the drive side, it just doesn't do it smoothly. This effect starts as soon as there is any angle other than straight intrioduced in the joint, but it's not noticeable until grater angles as it does increase with the angle.

You want the angle at the rear universal very nearly the same as the front universal joint so the effect is the same at both ends, and it's why you want the rear and front universals in proper phase with each other. Proper phase is when you consider just the shaft itself, the yokes at each end are in the same plane. This way the oscillations are both "the same" and when one is in it's speed up cycle, the other is in it's slow down part of rotation, net effect is they cancell each other out and the drive line operates smoother.

Get them out of proper phase and the effect is amplified, get's worse, vibration is felt.

No shims, the leaf springs rotate up through an arc with longer rear shackles, the pinion is both raised (in relation to front universal joint / trans output) and pointed downwards more, the rear angle is thus increased while the front universal joint's angle is decreased, thus the front unioversal joint is brought nearer to straight since the truck is lowered, while the rear experiences greater oscilations in speed ..... result is drive line vibration that get's worse at faster speeds.