Pinion angle

So, im pretty sure my leafs are warped rotating the pinion up too far. I have an SYE with a CV shaft installed. Already shimmed it with 8* shims. The angle on my driveshaft measures 12* while my pinion is at 22*. If I remove my current shim in there and add a 4* shim to bring the pinion down, that should get me by untill I get some new springs right?

So your saying you pinion is pointed 10* up over DS? Thats a lot! How much lift you running? 8* shims seem like a lot too.. Step it down to 4* shims and re check is about all you can do

Im running about 6 inches of lift. When I origionally put in the SYE the 8 degrees was right. Now that the bastard pack has sagged/warped I need to bring it down 12 degrees. For now im just going to take out the 8 degree shim to get me by until I get a new pair of leafs. Going through a ujoint a week is going to get old real quick. So with the 8 degree shim, im still 2 degrees up from my driveshaft. Is this acceptable? I know the range is within 2-3 degrees, and I also know that ideally you want it to be lower than the driveshaft. But for now i think its alot less.

Yay. No more vibes!

I have a 6.5 Rusty's spring pack in my 93, I used a 4* steel shim and it went perfect. No vib!!

Should be 1-2 degrees down from DS. Your axle rotates up on acceleration.

Locked98GC said:

Should be 1-2 degrees down from DS. Your axle rotates up on acceleration.

Click to expand...

I know ideally. But 2 degrees up is way better than 10. And almost no vibes. It will get me by until I can find the money for new leafs

EDIT: i rear wrong.

So back on to this. Ive changed out my springs. Specs are Clayton 4.5 springs, and RE 6 inch long boomerangs, TNT flat belly skid. Ive measured again, and it I measured the pinion being 3 degrees to high. So i installed a 4 degree shim to bring the angle back down. I think it actually got worse. I get a oscillating vibration/hum at about 70. Ill have to re measure my angles tomorrow. Ill try swapping shafts if the angles are good and see where that gets me. Im stumped. Ive never had a problem with driveshaft vibes.

I just went out and re meassured. Looks like 5 degrees measured from the machined surface on the back of the diff, and 15 on the driveshaft. Looks like I should have gone the other way the shim. And I should have measured today before putting the shim in.

Stop measuring off surfaces with have no relationship to the parts you are working with.

If you have a SYE with a Double Cardan as the joint on the Transfercase, the only angle you need to be concerned with is the relationship between the driveshaft and the axle pinion.

That angle should be 180deg (Straight) under power.

To accomplish this under power, you make that angle a bit more like 182 degrees to put the pinion below the drive shaft.

So if your DS/Pinion looks like \_ it's right (just not so extreme )

If like this: --\ it's not right and you need to fix it.

There is no set value of shim unless you have two lifts with the same exact hardware, same brand, same axle... then you can use the same value. Otherwise, you need to measure it.

So I removed my shims, measured angles. I came up with 12 degrees for he pinion and 16 on the driveshaft. A 2.5 degree shim would be perfect I think if I can find a steel one. Would a 2 degree be sufficient?