Drive Shaft Vibrations Solved Step-by-Step

Without seeming like a lazy ass, can you link that spicer diagram? I found this pic on their site and a driveline calculator but no pdfs.



It seems like my angles are pretty close to OPs, but you're saying that isn't ideal? On a side note, I had zero vibes with a 2.5" lift, jumped another inch with the OME kit I currently use created all these vibes. Pretty wild that an inch can cause so much headache (that's what she said)

 

This page jumped out at me:



They recommend at least one degree at each end of driveshaft. Since I'm currently at 0.4 with a 2.5 degree shims it seems I might need to decrease to a 2 degree, since I think that's the lowest they go.

 

Here ya go, the complete document. Go to the document's page 14 and reference Fig. 9 and Fig. 10. You will see that Spicer is trying to achieve the slope through the rear diff and the first shaft (the jack shaft) to be the same. They are parallel. My vibes finally went away when I did this. I also believe that is what Toy is trying to do with the big 2014 TSB. So my advise is to not stray too far from the Spicer recommendations. Your 0.4 degree at the rear diff is a long way from what you show as the slope of the first shaft. MAKE SURE YOUR TRUCK IS ON A PERFECTLY LEVEL SURFACE. And make sure you read the angle finder always on the same plane from the same side.
https://www.waterousco.com/media/wysiwyg/pdfs/content/J3311-1-DSSP.pdf

 

Sounds like I need to crawl back under and take measurements without zeroing the gauge. So if I understand correctly, the angle from transfer case to first shaft (3.8-0=3.8) should be <1.5º difference from the second shaft to rear pumpkin (4.6-0.4=4.2)? I'm probably missing a lot because that seems in spec to me.

Math r hard. I might play with it on paper tomorrow, I suck at visualizing these angles in my head

 

First get your truck absolutely level with the suspension relaxed. (Edit: this means the surface on which the tires sit on and not to anything on the truck itself. I have to shim under the tires). I am not a big fan on zeroing on anything and then making measurements because of the wildly different readings I would get that are traced back to the specs of the angle gauges.

If you dig into the specs of these gauges many have claimed accuracies that differ if at one angle and then at another. I collect these things and many claim +/- 0.2 degrees. That can be huge variance. For starters try to simplify this a bit. Try measuring absolute angles of just the first shaft and the diff and see what you get. On mine I also unbolt the shafts at the TC case and the rear diff to measure the big flanges of both as they are the only large flat machined surfaces and I had trouble getting measurements that would repeat due to with casting imperfections on both.

 

Good info, thanks. I'll try and get it leveled this weekend and take those measurements. I had some variance in my gauge but would let it settle and move it back and forth on the surface to get the most consistent measurement. Concerning the specs, would +/- 0.2 degrees be enough to throw off the driveline? Shim increments for the rear axle come in 0.5 degree variants, and I can't picture Toyota having a specific measurement for each angle in this driveline or we wouldn't have so many different configurations between trucks. If you have them handy, what did your numbers end up at?

Edit: Also, do you recommend to take the measurements off the transfer case and differential housing or shaft flanges?

 

Starting with your last question first, I could never get decent readings on the housings so I unbolted the drive shafts (block the tires!!!) and measured the flanges attached to the diff and Tcase not the flanges of the shafts. The flanges of the diff and Tcase are true machined surfaces large enough to get reliable and repeatable readings. But the slopes of the drive shafts were measured while bolted to those flanges.

I agree with you about the variance comments and in reality its probably not that critical. But you have to understand where I was coming from. I had a terrible time trying to get the vibes/shudder out of my truck. My comments are based on my experience because I grew to believe a large part of the problem I was experiencing was a result of measuring issues. I ended up walking away a couple of times but always still had the vibes but in some other mph range.

I kept notebooks full of trial-and-error attempts that were made. After a month or so the vibes were driving me nuts and decided to try it yet again. Once I replaced the rear transmission/transfer mount with the TSB one and did methodical measuring with a decent gauge (I use two now to verify readings) and measured with the truck sitting on a truly level surface I started getting different numbers so it appears that I was also doing something(s) wrong. In the end, the values I got looked very much like the Fig. 9/Fig. 10 of the Spicer document. Its what worked for me.

 

I really appreciate all the help. If it isn't unbearably hot I might pop my shafts off so I can get a true measurement and start with a fresh baseline. My vibrations seems only to be an issue at low speed but I'd still like to fix the problem now to avoid any additional strain to ujoints and other components.

 

Came across this site that apparently makes custom axle shims:

http://www.4crawler.com/4x4/ForSale/Shims.shtml#CustomWidthShim

Before I removed my CB drop kit, my numbers yielded a need for .5 degree shims. Since I thought nothing was available from any of the more common manufacturers, I removed the drop kit, remeasured and the second time, it yielded that I needed a 2 degree shim. I ordered the 2 degree shim kit from Headstrong and will just use that with no CB drop kit. But this seems like a nice alternative if you do not wish to remove the CB drop kit.

*I have no experience with them. A saw a video on Youtube of someone ordering seat spacers from this site and they had no complaints or issues with receiving their order in a timely fashion.*

Hope this helps some people out!

 

I'm not understanding the real world angles conpaired to what the speicer diagrams show. Speicer says first operating U-joint angle (x-fer case to 1st shaft) to be 1-1.5 degrees but most real work measurements appear to be 3-6 degrees? And finally all speicer says is to match first shaft angle to diff/pinion angle ( carrier u-joint & pinion u-joint will automatically be cancelling. Seems contradictory to what has been posted here ?

'with 3* shim'
Xfer case-0
First shaft -4.1 down
Second shaft-6.2 down
Pinion-3.1 up

Pinion is only 1* below first shaft no-load. When underload this should be much less. I still have takeoff vibes and vibes around 60-70 mph.

 

Bump

 

Will ome cb drop cause more wear on bearing? I have 2 inch front and 1.5 aal on 2015 Tacoma dcsb 4x4

 

I know thread is old but worth a shot . Low speed shudder on take off and around 60mph. These are with 3* shims installed already!

Tc=0*
1 shaft = 4.1*
2 shaft =6.3*(zeroed on 2nd shaft for pinion angle)
Pinion =3*

1-2 shaft angle is 2.2*
Pinion is 3.1*
Working angle of 1.1*

Thing I find odd is I already have a 3* shim installed [properly] and rear was only lifted 2.25" . Seems excessive to need a 4* shim ? Any input or expertise would be appreciated.

 

I had the same issues and added shims at the pinion and spacers at the cb for about a month every night. Finally got rid of them. I had a vibration at 20-30, take off shutter, vibrations at 50-65 etc. Every time I adjusted things the vibrations changed at different speeds. I would get rid of one to gain it worse on the other. Finally I added a helper spring in front of the axle and used a 3* shim on the pinion and flipped my cb. All is well now. My angles are. 6.5 pinion- 9.0 rear shaft 5.7 front shaft and 2.5 tc. Working angles are 2.5 pinion-rearshft, 3.3 rear shaft to front shaft and 3.2 tc to front shaft. The shudder was from axle wrap putting my rear working angle to high and the vibration at low speeds was the pinion angle being to low and the angle at the tc being to high.....too much cb drop. The vibration during applying the breaks coming to a stop was do to the pinion tilting down while breaking. So the what worked for me was getting the front two working angles as close to equal and having the pinion working angle set .7 lower working angle to allow for axle wrap and weight in the bed or towing. Note without the helper spring I would still have tale off shudder so it took care of most axle wrap by stiffening the leaf springs in front of the axle. And I have a 3inch spacer lift up front and a 2.5 inch block in the rear and the helpers added 3/4 more to that height, so 3-1/4 Lift in the rear. One last thing don't go by the angles of the times or shafts. Go by the working angles. I say that because my driveway is pretty level but when I measure angles when I'm backed in the driveway vs parked forward my angles are different but either way you'll have the same working angles regardless. I think if I measure my angles backed in the driveway they are 3.5 tc 6.7 front shaft 10 rear shaft and 7.5 pinion vs parked forward 2.5 tc 5.7 fro t shaft 9 rear shaft and 6.5 pinion. But the worki g angles will read the same on both. Doesn't matter how I'm level the ground. 3.2 front joint 3.3 middle joint and 2.5 rear joint.
I feel your pain. I racked my brain for about a month hours at a time. I thought i tried everything and though I would never get it right but finally got it and you will to. Good luck.

 

For what it's worth, 4crawler is who I ordered my driveshaft spacer from and the quality of parts and customer service is on point. Shipping was fast too.

 

Alright. Doing my best to make this right, but seeing that my efforts are going nowhere. Maybe my issue might help others. I have read through the very thorough solution and problem-solving of the OP. I really appreciate the depth of knowledge from the community. I feel I'm close to fixing this, but want to verify.

Here's what I have:
- 2017 DCSB TRDOR
- OME BP-51 w/ medium leaf pack. No relevant weight in the bed.
- ~150 lbs in the front
- ~150 lbs from sliders
- 285/70/17 Duramax
- OME CB shim installed (came with the kit)

I did the install of everything

What happened:
I got vibes after driving around the block once the rear kit was installed, which makes me think this is a driveline issue.

The Vibes
I get vibes between 20-30 mph
I get vibes at deceleration and braking

My elimination process:
- Originally thought the vibes were from the needle bearing, but they started the instant I put the back lift on. Dismissing that theory for now. I have the spacer but have not installed yet.
- Dealership thought that the CB needed to come down further, so added an additional CB shim from OME. That made things worse.
- Took the truck to 4wheel parts to inspect my work on the overall lift (always good to have a 2nd set of eyes) and they said everything looked great. Not super impressed with their expertise.

Here are my measurements from the OP's worksheet


My fix hypothesis:
- My pinion is pointing up, so I need to get a 2 degree shim to point it down
- That will make my angle greater between the first and second shaft, so I might need to add an addition CB shim.
- My driveline is unbalanced. Hard to think this is the problem given the immediate vibes from rear install
- My driveline is not aligned at the CB. Also hard to believe given how many times it's been adjusted and the vibes are exactly the same. Although if anyone has a step by step to align the DL, please shoot me a link.

Any thoughts? And thank you in advance.

 

To align your driveline I used a string and tied it to the zerk fittings to get it straight. I gave up on trying to fix my vibes for a while now once I got them to just the takeoff shudder, but I'm gonna give it another crack. I was thinking, I had zero issues with my 2.5" spacer front and 1.5" AAL rear. The vibes showed up when I went to the OME kit with Dakar HDs rear, not sure how much lift I received total but probably an additional inch. I've been fooling with washers to try different CB spacing, but what if I need to go much larger? The body of the truck increased in height from the axle, so theoretically if I space the CB to compensate for that lift (0.5-1"), it should be back to where it was pre-OME lift. Right? Bueller?

 

Did you end up installing the 2 degree shims?

 

Reading through this, some seem to say to install shims fat side forward. Toytec and other companies advise me to install skinny side forward and most seem to do this. For the people installing backwards (fat side forwards) did you not have a lift and were stock? Doesn’t make sense that someone with a 2” lift would need to install them backwards, yet another person with a 2” lift installs them the regular way.

 

I've wondered about this too. Looking at the angle of the rear axle from the side it looks like it's angled down after lifting, but when installing the shims we orient the shims skinny side forward, tilting it further down. I'm sure the angles change once the rear axle is under load from the drive shaft, so maybe I have no idea what I'm talking about.