Drive Shaft Vibrations Solved Step-by-Step

Good to know.
I've only been up to 50 with it and has smoothed out what I was feeling.
Perhaps it'll show at higher speeds.

 

So I downloaded an inclinometer app and used this video for reference.
1.5" rear lift without cb spacer. With that wedge that's been under the leaf pack. My numbers come out pretty flippin good. The addition of a cb spacer was no bueno.

https://youtu.be/f1m-Fh5kiRU

1st underline number s/b within 0.5- 0.8deg
2nd and 3rd underlined s/b equal.
(working angles) and between 1-3deg.

 

How are folks getting accurate measurements on the two flanges? The video above shows a phone up against the edge. I've tried that, as well as a small digital angle finder/level, but I can't seem to get it flush against the edge, to where I can get an accurate/repeatable number. Does the driveshaft have to be in any particular orientation (ie: do the yokes need to be centered/pointing straight down to the ground)?

 

I happened to be using a flat carpenters pencil to write so I was able to slide that against it and hold the phone against the pencil.
If that aluminum block was my phone/level.....

 

I'm half-joking, half-serious here: I can tell that this is the correct way to approach this problem just from the clarity & orderliness of your penmanship. Will be using this method to track down a very quiet slow-periodic (peaking every 2 seconds or so) driveline vibe I can only hear on completely smooth pavement, coasting in 2nd/3rd gear, under 30 mph. This vibe began after lifting ~1.5" front w/ FOX 2.5's, and 2.5" to 3" rear w/ FOX 2.5's and Deaver stage III's.

 

Thanks for the pictures, @bkhlrTaco's - much appreciated.

 

His truck probably still vibes a little too. lol. It's a truck and there's probably always going to be a little if you feel hard enough for it.
As long as Front ujoint is around .5deg and center to rear are equal, and between 1-3deg, you're O.K.
I drive mine to work. lol

 

Not on my watch! There were no noticeable vibrations for the 12K miles I owned & drove the truck on stock suspension & ride height.

 

Some guys in this thread have had mixed results using my method, so don't take my word as gospel. I taught myself all of this stuff just like (almost) everyone else here.

Mine has zero detectable vibes*, regardless of speed or how hard I mash the skinny pedal. I'm paranoid about any feedback from my vehicle, so I'm sure I would notice if something was off.

*I'm gonna go knock on wood, like right now.

 

Mine had zero detectable vibes too until I started using T.W. heh
Now I notice every little noise.

 

I used a 90 degree T angle. The magnetic edge of the angle finder sticks to it, then you can put the other end of the t flush against the flange.

 

My Ujoints squeak in reverse (but they already did b4 the 2.5” lift). After the lift it had a tiny vibration but I think going from 30.5” tires to 32s totally fixed the vibration. Still need to replace the ujoints because they squeak though. I did put in the 8mm spaced that came with the kit just because it said to

 

Got a question for y’all.

I’ve been trying to chase down some high speed vibrations, at about 65-85mph.

I took measurements of my driveline based on this post:

Truck: 2012 DCLB prerunner, 2wd
Pretty new carrier bearing with less than 10000 miles on it. Fresh rebuild driveline with a slip yolk added in the rear section by a competent driveline shop in Southern California at that time too.

• The difference in degrees from the output flange on my 2wd prerunner DCLB to the rear axle third member is -0.90°.
So my axle input is pointed upwards at a steeper angle by almost a degree relative to the trans output.

• The difference in angle between the front and rear driveshaft is exactly 0.0°. They are dead even.

I am still a Little confused on where everything should sit.. do these numbers seem ok? Or would the -0.90° difference cause pretty harsh vibes at freeways speeds?

If so, not sure how I would go about correcting a negative 1 degree. Install an axle shim backwards ?! That does not seem like a good idea lol.

TY in advance tacomaworld.

 

My post above #1142 is what I went by. Shouldn't be at 0 anywhere, from my understanding.

 

So I'm currently dealing with a vibration at around 60-65 mph and a grinding noise when I coast between 70-60 mph. Many have said that carrier bearings and the such need to be adjusted but I don't have that as I got a single cab. Really am wanting to fix this this coming week as its been like this for a while and I have some down time. I took pictures of my angles, not sure if they are correct but I can always crawl back down there and redo it if I need to.

I ended up zeroing out the angle app at the Transfer Case on a flat surface then got the angles on the image below. I got a shot of my driveline and my suspension also in case that adds some context. Truck has a 3 leaf wheelers add a leaf kit and Bilstein 5100s in the rear. All the U joints were replaced with Spicer units and are greased every oil change.

Are shims needed to get within spec for the vibrations to go away or is something else needed such as removing the overload leaf? Thanks for all your help guys!

 

Doing some searching it seems that a 3 degree shim should be used. I'm wondering though if to correct that I could remove the overload leaf. Are there many that are running that overload leaf and that causing minor vibrations to go away?

 

You will still have the vibrations, even with the overload leaf removed.
If you measure after taking it out, you will might end up needing 2.5 degree shims.

 

So I'm guessing that the idea would be to zero out at the TC and the diff?

 

Any answers? Most the comments here I find are for 2 piece shafts....truck is going in the shop here soon and I'd like to get the right shims. Sorry if being a bit demanding...

 

i really don’t know enough to give good advise, but if you’ve taken measurements and see that the working angle of the x-fer case is 9°, and that the working angle of the rear diff is 6° (9°-3°) — sounds like a 3° shim should work.

only thing I’m a little gray on and have trouble picturing if I’m not literally looking at my own truck with an angle finder,is that I would ensure a 3° shim would actually get you angles to match, and not put it further out of spec. Ie. 9° & 9° Not 9° & 3°.