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Well its time to take out the old blocks and put in some straight springs. I need to verify i am comprehending this correctly for shim placement. I believe i am running a double cardan and should be having the rear axle angle match that of the drive shaft as seen here
But i am currently running the angles (both transfer and differential flanges are 3 degrees) like a two joint shaft as seen here
This is what is confusion, the rig runs fine and has been this way since i bought it. There is no shims under blocks and the block measure the same front to back.
Now if i had to assume, my current setup is wrong but thats why i am posting this so i dont have to assume. The new springs comes with a built in shim that i think will fix this or maybe i am looking at this wrong...
This is front of drive shaft which i believe makes it a double cardan
This is the block, no shim
Finally this is the rear axle which you can see is not pointed up towards the driveshaft
To make a long story short, with my setup, the rear axle should be following the angle of the driveshaft or follow the angle of the transfer case? Thanks!
Well the built in wedges didn't do so well, getting vibration about 70mph (wasn't any before the spring swap).
Running the procomp 23311 rear springs with the fat side of wedge towards the back since I was trying to angle the diff the same as the driveshaft.
This puts the transfer case at 3 degrees downward, driveshaft 8 degrees down and axle 10 degrees pointed up to transfer case. The wedge measures 3.75 degree.
I have to tear into her again and am thinking to just go back to how it was since there was no issue. The easiest thing is to turn the wedge around which if I am thinking will give me a total of 7.5 degrees of angle change bringing the axle to 2.5 degrees (.5) off of the before. I will try this first since it doesn't require removing the springs, wedge removal or change will require at least spring to be unbolted to access the stack pin..
With a CV you typically want the pinion angle down roughly 2 degrees because it torques up under load. With a heavy duty pack this may be less true, but would likely still be fine.
Go ahead and try no shim but just get the u-bolts tight but not torqued. They should technically be replaced if they've been torqued but this gets spendy if playing with multiple setups
U bolts are designed so that when you torque them down, the threads deform and effectively lock together. If you've ever really looked at the threads of a used U bolt the threads where the nut was are usually rounded over versus being the correct "V" shape they should be. If a U bolt has been brought to torque, even once, they should be replaced.
I know, I know........ people have reused them forever...doesn't mean it's the correct way of doing it. U bolts are cheap..even if you end up buying 3 sets..which would be alot...it's only gonna be like $175 at the most....just replace them.
Yeah I got a new set of u bolts that I will put on when I get my final angles squared away.. I did reverse the shim which helped, but am thinking it will be better if I ran no shim or a 2 degree shim, going to try to zero the pinion angle with drive shaft. I was pointed 2 degrees higher then the drive shaft. So zero or a little lower of an angle is what I aiming for.
To close this out i went with no shim and got a 2 degree downward pinion angle vs driveshaft as recommended above. The reverse wedge helped the vibration but had a 6 degree working angle at the driveshaft/pinion angle which i didnt like. It has a set of new ubolts.
A few things that i could not find any info about. The procomp 23311 uses a 4 degree wedge (the 3.75 degree above was from eyeballing with the tape measure but once out am able to get an accurate measurement). The wedge is aluminum. Well thats my story.
04-17-2022, 02:42 PM
