Drive Shaft Vibrations Solved Step-by-Step

I measured a bit earlier today and measuring everything again I hovered around 2 and 3 degrees for the rear. If I pushed my phone against the diff I'd get 3 degrees if I relaxed it just a tad the diff turned to 2 degrees. I bought 2.5 degree shims. We will see how it works. It's gotta be better than what I have now.

 

Unlike others with the impeller shaft, your 1 piece driveshaft should be pretty easy. For you it's all about rear axle shims and which degree shim works. I'd say 2 1/2° shims will be pretty close.

 

I gotta say though, 60-65mph vibe might not be caused by your driveshaft angles. And anything grinding surly wouldn't be on a one piece shaft. You might have something else going on but the 2.5° shims probably aren't going to hurt, even if that's not the problem. Good luck.

 

How are you liking option 3 after more seat time?

 

I love it. Definitely need the weight to wheel it. I’m around the 200 lb mark and would like a little more to make it feel better. Iv had a few issues tho. With them being stiff the front wants to flex more so the sway bar makes amazing noises. I have taken it apart and greased it. That worked for a couple weeks maybe a month or two but it’s back now. I would like to remove but I need to go to a full 3 inch in the front and 650 or 700lb springs to do so with the amount I drive on the highway. I have done 500 plus miles off road so far and I would say unless your really wanting that smooth ride most dream about the third option is a go to. The amount of flex I gained over stock is insane.

 

this may be a dumb question, but how important is it that these measurements are taken on flat ground?

 

I’m going to say it depends and the reason why is if your truck is at an angle and the rear axle is torqued to keeping the truck from rolling it’s going to change your rear pinion angle. It could be pointing up or down depending upon what direction the force is applied. If you are on relatively flat ground then I wouldn’t be concerned.

 

latest update

 

Vibe free?

 

I can’t say vibe free, but significantly better. Prior, it would shake considerably at 70ish MPH while holding or slightly increasing speed. Passenger backrest shaking all over the place. That is now fixed. The vibe/shake felt between 30-35 is also fixed. It rides sooo much smoother.

Now, I say fixed, but not gone. You can still feel both places that it would vibe before, you just really got to try to feel it, but it is there. It is definitely acceptable, but not gone. I’m going to experiment with a 3 degree spacer to see if I can get rid of that last .4 degrees of difference. Maybe it will make a difference, maybe not, but I’m fixing to find out.

I think most people would call it fixed at this point and call it a day. I’m very OCD about this though.

I can definitely say that the CB Drop did nothing to fix the vibe and actually made it worse at higher speeds. I have read where some people flip the CB upside down to decrease the space instead of increasing it. I might try that as well, but would then, most likely, need a 3.5 shim or greater to offset that. I’m not sure if I am going to go down that road yet though. I think the 3 degree shims might be the final fix for me.
We’ll see. Once done, I will update the graphic with the results of the 3 degree shims.

I hope this helps others.

 

Anyone get 6* up from TC (0*) to rear pinion flange? I have 3* shims and they look to be oriented the right way. Am I going crazy here?

 

any thoughts

5 to 10 shudder. 40 to 60 slight vibes. Anyone know how i could tweak this to smooth it out?
Prerunner 6 inch lift.

 

What app is that?

 

Spicer driveline calculator

 

I was going to do option 1 also to try and get rid of the vibes but it would put my first angle at roughly 5.5degrees. Do you remember what it put yours at? Also mine is vibing at 35 to 60 right now. Did you have any at those speeds before you lined up the shafts and pinion ?

 

My 2010 Sport 4x4 is not lifted. I disconnected the rear drive shaft to remove the 3rd member and have bearings replaced and when I reconnected the drive shaft I immediately got vibration starting at 35mph and at various intensity up through 80mph. Replaced ujoints, CB, then replaced unjoints with Spicers and had the drive shaft balanced. Next I replaced the Dorman CB with Spicer CB. NO CHANGE! I started measuring angles: Zeroed gauge on front flange. Front DS 4.1 degrees, rear driveshaft 1.0 degrees, Pinion flange: +2.5 degrees.
My current theory is that the ubolts on the rear end were only torqued to 37 foot pounds when the PO had the springs replaced (I put a torque wrench on them and it took many turns to get to 90) and when I supported the truck with jack stands under the bottom mounting plates of the rear axle, the axle rotated just a little up changing the pinion angle. Maybe the jack under the 3rd member supplied the moving force to rotate the axle. I've driven this thing over 10K with the vibration and it's annoying and frustrating that nothing I've done so far changes it. Open to suggestions.

 

You can try unbolting the impeller shaft at the axle, rotating it 90° or 180° and bolting it back up.

 

I forgot to mentioned that I rotated the driveshaft through every mounting position at some point---no change to the vibration.

 

Is the front shaft 4.1° + or - off the trans?

 

- 4.1 off the TC flange