OME Light/Medium 2.5" Lift and driveline vibrations (1 Viewer)

[AutaviaFJ40]

I am far from an expert and may have missed this in your thread but here is my 2cents
If the shims are facing toward the back it would rotate the axle down, as such the pinion angle may be at the wrong angle to the TC. Again I may be way off but my understanding is shims face forward, rotating axle/ pinion upward. With your lift and shackles it would be 4 degrees.
If you do the search thing you May see more on shims

Which is the correct direction of the shim? I installed the 4* like this- with the wedge facing rear:
https://forum.ih8mud.com/attachments/shim-jpg.2534628/

The only thing I didn't try was the 4* the opposite direction. I tried 2* both directions, and no difference

 

[Crush 4]

Which is the correct direction of the shim? I installed the 4* like this- with the wedge facing rear:
https://forum.ih8mud.com/attachments/shim-jpg.2534628/

The only thing I didn't try was the 4* the opposite direction. I tried 2* both directions, and no difference

For the front axle, I faced the fat part forward

 

[AutaviaFJ40]

thanks, and what about rear?

 

[Crush 4]

thanks, and what about rear?

So I had a slight vibration before winter set in and I haven’t done the rear yet. I’ve done a lot of small things though, in terms of adjusting steering arm, steering box and got a whole new set of wheels and tires. I’m gonna run with those when spring rolls around and then see if there’s something else I need to do.
What tires and wheels you running?

 

[AutaviaFJ40]

Nitto Terra Grappler LT295/75R16...im considering going back too stock wheels once these tires need to be replaced. They were installed by po

would the front wedge have any effect on vibrations though? I do plan on addressing front, I wanted to tackle the vibration first

 

[Crush 4]

Nitto Terra Grappler LT295/75R16...im considering going back too stock wheels once these tires need to be replaced. They were installed by po

would the front wedge have any effect on vibrations though? I do plan on addressing front, I wanted to tackle the vibration first

Like you, I have been chasing vibration and rode manners. My wheels were 15” steelies w BF’s 32 or 33’s. I’m going with 255/85/16 on a 7” cast aluminum steelies . This along with other steering updates/adjustments will help road manners. The front shims were to help caster.
In terms of vibrations, I hadn’t pinpointed it prior to winter. I had been reading a lot about rear shims and pinion angle as I have a 2-3” lift and extended shackles . Once new tires are on I’m going to re measure the angles and see.
I’m hoping that I’m getting close!

 

[-MaTTi-]

Merry Christmas All

If I measure flange to flange the top is 22 3/4" and the bottom is 22 1/2"
measuring with a tape measure so not precise.

based on what I read here, the top should be about 1/8" shorter...so how do I accomplish this?
As I read this, I'm 4 degrees off, but I failed geometry ...did my shim over correct?

View attachment 2534664

View attachment 2534666

Which is the correct direction of the shim? I installed the 4* like this- with the wedge facing rear:
https://forum.ih8mud.com/attachments/shim-jpg.2534628/

The only thing I didn't try was the 4* the opposite direction. I tried 2* both directions, and no difference

Like you have installed and how that picture shows

you should get the same distance.

 

[1911]

You want to shim it so that the working angles on both u-joints are equal but opposite.

Here is a photo of my rear, after a 3" lift, longer shackles, and shims (I don't remember what degree of shims now). I was able to get the working angles withing 1 degree of each other which is acceptable, but there is still a slight vibration in 3rd gear at about 2500 rpm.

rear drive shaft geometry

• 1911
• Dec 19, 2017