Off Roading Forums banner

Driveshaft Spacers or Shims or Both ??

317 views 4 replies 5 participants last post by  DougO 
#1 ·
I'm SPUA,using 2 1/2" Rancho CJ's (4 leaf) in the rear. I've also moved the axle back a little less than 1/2". I'm experiencing a slight vibe, nothing horrible, but annoying to me. Should I do a Toy CV DS with Rockrat adapters, a stock DS with spacers, or use shims on the spring packs?

Or, any combination of the above...?
Any ideas??.........
 

Attachments

See less See more
1
#2 ·
From the pic. you attached, everything looks to be fine. Your pinion angle looks o.k. & you look as if you have plenty of spline left before the driveshaft seperates. Have you checked the u-joints & stub end splines? That'd be the only thing I can think of right now. Have you re-torqued the u-bolts?


Of course, you can't wrong with the toy shaft + adapters.

Brad.
 
#3 ·
Crow, Is that pinion in-line with the driveshaft? It looks to be from that picture. If it is, a double cardan (CV) driveshaft is needed for vibration cancellation.Spring shims are the cheapest way out, just be sure to get the steel ones, not aluminum.
 
#4 ·
I just replaced the U-joints in my rear driveshaft Saturday.....I didnt realize how much vibs I was having till I changed them. May want to try this first....may not fix the problem but it is something that even if it isnt a the problem it will give you piece of mind knowing you have good u-joints in.
 
#5 ·
To cure the vibes you need to find out your angles.
Start by rotating your drive shaft so the ends that attach to the flanges are flat to where you can put the protractor on.
Next put the protractor on the tcase end record the degree then the center of the driveshaft record the degree then the pinion end and record the degree.
Now subtract each flange ends from driveshaft to get each working angle, then subtract the working angles it should be 0 to 1* anything more will create vibes.

EX
[ ] = flange
x = Ujoint
--- = driveshaft

]x--------x[
8* 12* 7*

12-8=4* upper Ujoint working angle(should be between 1*&7*)
12-7=5* lower Ujoint working angle
5-4=1* Parrallel compensation angle(vibration angle)
Good angles

Bad Angles
]x--------x[
9* 13* 12*

13-9= 4*
13-12= 1*
4-1= 3* = vibes
In the case of this you would use shims to decrease the pinion angle. Now, if youuse shims to decrease the pinion by 2* that will now add 2* to the driveshaft, so as a rule if you subtract from one you add to the other, and vice-versa.

Bad angle Fixed
]x--------x[
9* 15* 10*

15-9= 6*
15-10= 5*
6-5= 1* = good enough
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top