Driveline Vibration. Need HELP!

Is anyone using a 3 leaf icon AAL with a 4 leaf TSB ?

 

Sub'd

 

Did you happen to check your ujoints? I would only be focused on the angle between the rear diff and the center bearing, the angle between the tcase and that center bearing would not have changed lifitng the truck, and dropping that carrier bearing will only screw up the angle worse. I just installed an fj80 axle and we pointed the pinion a few degrees down from pointing right at that center bearing and i am vibe free, and we didnt touch anything else. The interesting part about the 80 axle is its offset to the right by 3inchs so pinion angles critical.

 

Everything is so conflicting that I read. I guess it's just going to be a trail and error situation right now. I was curious if anyone out there has the same rear setup as me and to see if they got any vibrations.. And what fixed it.

Wouldn't a faulty u joint cause a vibration at any speed? I'm also thinking it's not because I have good movement when I disconnect the driveshaft.

 

Sub'd for possible future diagnosis...

 

A bad u joint will cause vibration when you are on the gas and if its really bad when you are off. Lowering the carrier bearing is a band aid that moves the angle further towards the tcase. What you need is some degree shims and leave the pinion 3 or 4 degrees down to account for axle wrap.

If you have a welder, you can cut the perches off and weld some new perches on with the axle at the correct angle.

 

sub'd....some good info here

 

I have 3 degree shims pointing pinion up, thicker end of the shim towards the rear. I do admit my vibration decreaed after installing them. Vibration before shims were from take off till about 30 mph. After installation vibration only at take off till about 10 mph.

 

How bad are they? If they are just shaking the rear view mirror a bit up to 10mph i would call that mitigated! You wont get much less vibes than that unless you install a traction bar which may be a little overkill depending on how you use your truck.

 

Lol no it's not shaking my mirror. It's a shudder, it's felt throughout the truck. Can I live with it? Sure if I had to I would. But I do think it can be eliminated. Yes it's very annoying to keep going under there and change shims and adjust the cb. I want to go to a lower shim or take it out completely but would like some advice with my angles that I posted where to go next.
If it really is axle wrap, why would it start happening after I lifted the truck and not stock?

 

If it's axle wrap, it was happening before the lift too but you just didn't notice it because the pinion angle was OK. If you are getting vibes at low speeds w/out being on the gas too much, I wouldn't attribute it to axle wrap, since that's only going to affect upon heavy torque. By the way, I removed my carrier bearing drop and now vibes are pretty much gone. Again, I have the stock 3 leaf with an AAL. My angles are 3 degrees from output to first shaft, 0.2 degrees from first to second shaft, and 2.2 degrees from second shaft to pinion. I'd say that's pretty good because my pinion U-joint phasing is cancelling out my output U-joint phasing, where the middle joint is essentially acting as a straight shaft. I think my problem is solved now.

 

After driving around some more, I found that the vibes are still there, but just not as bad as they were before. It was never that bad, just a little shuttering as I approach a stop.

 

Where is everyone purchasing the Axle Shims?

 

I bought mine from headstrong but wheelers has steel shims if that's what your looking for.

 

To be honest, I'm not too sure what it is I'm looking for...except for eliminating the nasty vibration I'm getting. I just had my driveshaft serviced(all 3 unjointed replaced, new carrier bearing, etc) and now my vibrations are happening around 20mph and increase a bit the faster I go. I'm not too sure what I need to do.

 

Good info on here!

 

What tool did you all use to determine the angles & where can I buy it?

 

I used this , I already had it though

http://www.leevalley.com/US/wood/page.aspx?p=67350&cat=1,43513

 

I tried out the clinometer app today, but it seemed kind of tricky, getting a consistent reading.

 

Pick up a tom woods one piece drive shaft with a double cv at the output shaft. No more vibration issues. Not sure why toyota keeps using a carrier bearing other than clearance. Just more parts to have problems with.