[4.0Rubi]

I've recently replaced my stock drive shafts with Adams Driveshaft a 1310 rock crawler HD shaft in the front and 1350 rock crawler HD shaft in the rear. My TJ Rubicon is stock ( No Lift).
There's now a steady vibration over speeds of 50 mph.
It doesn't affect steering at all.
There was no vibration from the tires or anywhere else prior to the new shafts.
Any ideas of how to fix this would be greatly appreciated..

 

[Water Dog]

Is the rear drive shaft a stock (two u-joint) shaft, or is it a double cardan (three u-joint) shaft? If it is a double cardan shaft, you will need adjustable upper rear control arms to adjust your pinion angle.

What was the purpose of changing drive shafts on a stock height Jeep?

 

[4.0Rubi]

Thanks. The U joints were going bad. Rather than replace them, I just thought I would replace the whole assembly.

 

[Water Dog]

Thanks. The U joints were going bad. Rather than replace them, I just thought I would replace the whole assembly.

Uh, Okay, so is the rear a stock type drive shaft or double cardan? Also what year is your Jeep?

 

[4.0Rubi]

The Rear is a double cardan CV Drive Shaft.
2006 TJ

 

[Jerry Bransford]

The Rear is a double cardan CV Drive Shaft

I think I know the problem. If you didn't raise your pinion angle to match the requirements of the new CV driveshaft, you'll end up with vibrations.

Your rear pinion angle MUST look like the below top illustration for a CV driveshaft. The first drawing below shows what you need now, the second bottom drawing shows how it was set up for the OE factory driveshaft.

 

[4.0Rubi]

Awesome. Thanks Jerry.

 

[Water Dog]

Your rear pinion angle MUST look like the below top illustration for a CV driveshaft. The first drawing below shows what you need now, the second bottom drawing shows how it was set up for the OE factory driveshaft.

X2...Yep, better order up some rear upper adjustable control arms.

 

[4.0Rubi]

New Rubicon Express Rear Upper Control Arms installed, Pinion angle adjusted and I still have a vibration starting at 45 and getting worse.
What's the next step in solving this?
Thanks

 

[Water Dog]

Take a picture of your rear pinion angle (showing the drive shaft also) from the side and as much perpendicular as you can, and post it up.

You can unbolt the front drive shaft at the differential, tape the u-joint caps on and securely tie it up out of the way, then take it for a drive. If the vibe remains, it's in the rear shaft/pinion angle, if it is absent, there is an issue with he front shaft.

 

[C.L.]

Was the Jeep supported by the axle or frame when you set the pinion angle? That angle (and most suspension work) should be done at resting ride height. If you were supporting it from the frame, the axle was at full droop, and likely changed when you lowered it.

2nd step (which i would have done first) is to test each shaft independently. Pull the front shaft and drive around to see if the vibration disappears. Then put the front shaft in and pull the rear shaft out to repeat the test. Put the transfer case in 4wd and you can drive around on just the front shaft. Take it easy accelerating and cornering though, Wranglers are kind of squirrely in front wheel drive mode.

 

[4.0Rubi]

Thanks for the advice.

 

[4.0Rubi]

Rear driveshaft was removed today. The Jeep drive without vibration. The stock driveshaft was put back in but there's still a shudder whenever the trans goes into overdrive. Adams is sending a new rear driveshaft. I guess the best step is to put the new shaft in and see how it goes.