Rear Wheel Bearing Vibration?

[OregonLC]

Somewhere above should be a post with my angles and numerically they're fine. I've swapped the rear shaft with our other 100 and it neither cures the vibration on mine nor induces the vibration on the other so I don't think it's the shaft. Thanks for the diagnostic stuff.

I guess I should also add that I've not only physically swapped out different wheels and tires but I also just had them balanced and none needed over 1 oz. I've checked wheel runout and they're straight. Roundness is within 0.21" per the balance guy. So I don't think it's wheel/tire.

I'm going to play more with the pinion angle. It is torque sensitive and it is reduced when either foot or handbrake is applied so axel wrap is a likely candidate.

 

[abuck99]

Not sure if I asked before, do you have wheel spacers or aftermarket wheels? Are the lower control arms stock? You might have some wrap if your LCA's are original, but it wouldn't be significant.

And you ruled out rear wheel bearings?

 

[OregonLC]

So in the front I have TC uppers with stock lowers. The uppers have fresh bushings, the lowers are due, but there shouldn't be any wrap in the front.

If you mean links rather than LCAs, the lower links in the rear are also MetalTech and are solid.

Back in March I took it to Toyota thinking it was wheel bearing but they refused the work saying they were fine.

 

[abuck99]

So in the front I have TC uppers with stock lowers. The uppers have fresh bushings, the lowers are due, but there shouldn't be any wrap in the front.

If you mean links rather than LCAs, the lower links in the rear are also MetalTech and are solid.

Back in March I took it to Toyota thinking it was wheel bearing but they refused the work saying they were fine.

Yeah sorry to confuse- I was talking about links not front control arms.

I found your diagram of your operating angles. If I am interpreting your notes correctly, your pinion is pointing down 2.3 degrees and your output flange is pointing down 2.5 degrees- right?. You want your pinion to point UP +2.0 to 2.5 degrees to be parallel with the output flange. That would require almost 5 degrees of upward adjustment from where you are right now.

 

[OregonLC]

No it's a sloppy drawing, they're within 0.2 degrees of each other (almost parallel). My next step would be to lower the rear pinion angle under the theory that I'm picking up a degree or two under axle wrap.

 

[abuck99]

Regarding axle wrap theory: I dialoged to Tom Woods and also our local cruiser repair shop( well respected) regarding axle wrap a few months back when I was chasing my vibe. They both concluded there would be minimal axle wrap on 4 link suspension especially with fresh bushings. Since you have upper & lower links with poly bushes, I do not think axle wrap is the issue. If anything I would point the pinion up a tad more and see how it feels.

 

[OregonLC]

I used a go-pro to make a video under load and there is a bit of wrap, but it's not excessive. Maybe a degree. I'm going to pull the rear again and re-measure. Fortunately the MT links give me a good deal of adjustment.

What was the solution to your vibration?

 

[abuck99]

I still have a slight vibe but it's significantly better. Mitigated by re-balancing the driveshaft (high speed 3000+rpm), my pinion was pointed down too much and I raised it about 2 degrees which reduced 80% of the vibe.

What are you using to take your angles with? Digital or analog tool? If you have an lateral alignment issues that would cause vibes as well.

 

[OregonLC]

I've had the drive shaft balanced by two different shops, albeit neither specified 'high speed'. The only reason it was balanced a second time was because it was lengthened by the axle shop I used because they said that there was insufficient spline engagement. Regardless, it doesn't vibrate when I move it over to our LX so I'm doubtful it is drive shaft related, other than potentially angles. Nor does the LX shaft stop the vibration when put on the LC. (As a point of interest, they're two different diameters, the larger being from the 04 LX presumably because of the increased torque of a lower 1st gear in the A750 trans).

So wheels/tires are ruled out. Wheel bearings have been checked and are ruled out. Front shaft is ruled out. I've had both differentials checked (by both myself and two different shops) and they check OK. And if it's a gear issue, it should present itself at all speeds, not just highway. Could be in the t-case but I think that's OK (feels fine, drains clean). There is substantial 'clunk' when shifting between D and R, but I'm not sure that correlates.

I do have what I thought was excessive play at the big end of the CVs (next to the front diff, both sides, play is lateral not in-out). However, checking the LX it has the same play and no vibrations. So I don't think this is the issue.

I'm going to revisit rear pinion angles (again). It was done with a digital gauge (iPhone on a straight edge). Seems more sensitive than any of the dial gauges that the shops use. While the truck is lifted (progressive rate OMEs in the rear), it's also heavy (7,500 lbs total, 4,300 lbs on the rear axle) so it doesn't really sit up all that high making the angles relatively flat.

 

[spressomon]

I have experienced various driveline vibes since having 4.88's swapped in 11-years ago. After protractors on TC & rear pinion flanges and commensurate pinion angle changes to match what the "experts" say, along with too many different settings & tweaks to fully count, I finally gave up and fabbed my own adjustable rear upper control arms and went about playing with different pinion angles.

I was, after much trial and error, able to tune most of the driveline vibes out.

Some driveline vibes were/are difficult to impossible to discern unless I was running a AT tread.

 

[OregonLC]

Do you recall what you ended up with for angles?

 

[Julian Stead]

I haven't read all the posts, but the rear gearbox mount is what reduced my vibrations the most. I think when bushings, mounts, well anything rubber deteriorates it transfers vibrations to the cabin. The 100 cabin resonates like a tuning fork from any small imperfection which is why every thing seems magnified. So body mounts, shock cushions, engine mounts
All rubber really need to be checked or Ideally changed if in doubt. I changed all mine other than shock cushions and I find it has become acceptable at highway speeds, not perfect but ok. Wet weather is when mine is still more noticable, I think small vibrations come from the tires when dispersing water so shock(ahc) bushings and cushions are next on the list,as they look very worn. It used to be hot weather that improved things slighty, that is why I went down the rubber route adding to the issue first. You can end up chasing your tail if it is a rubber issue as your remedial work can alter the symptoms but the issues still exists in some form, if that makes sense. Mine wasn't a vibration as in shaking, just a hum through the body from the rear end.

 

[spressomon]

Do you recall what you ended up with for angles?

No clue. My LC is in storage; unfortunately I can't measure it for you. But not sure it would really do much good based upon all my trial and error. Its a little bit of a sucky job (not difficult per se, just time consuming) but probably something you might want to try. Before I got around to experimenting with different pinion angles I even, after the recommendation from a local driveline speciality shop, lowered the t-case ... to no avail.

 

[abuck99]

Angles will be fairly unique to each truck. The fact that your TC output flange is 2.5 Degrees down, and mine is less than 1 degree down makes it hard to utilize others settings. The goal is to get them parallel, / --- / then add .05 to 1.0 UP or slightly more to the pinion in order to load the needle bearings inside the spider/cups.

Some good info supplied here, especially what Julian mentioned. I would say his explanation best describes what I have going on. And Spresso is right on, its a sucky job to adjust out the vibes from the drive line.

Hope you get it sorted (sooner than later),

 

[OregonLC]

Yes, it's a PITA of trial and error. Fortunately the MT adjustable links make it possible.

 

[OregonLC]

Angles will be fairly unique to each truck. The fact that your TC output flange is 2.5 Degrees down, and mine is less than 1 degree down makes it hard to utilize others settings. The goal is to get them parallel, / --- / then add .05 to 1.0 UP or slightly more to the pinion in order to load the needle bearings inside the spider/cups.

Some good info supplied here, especially what Julian mentioned. I would say his explanation best describes what I have going on. And Spresso is right on, its a sucky job to adjust out the vibes from the drive line.

Hope you get it sorted (sooner than later),

The 2.5 was relative to earth, not the vehicle. Sloped garage floor.

 

[abuck99]

Got it

Helps to zero out the gauge on the garage floor prior taking driveline measurements. I tried using the iPhone but it's not easy to take consistent readings, or to stick it to the drive line part.

Fwiw the HF digital angle finder is a good tool for this job. Compact- you can stick it on the flange with out removing the DS, it's magnetic, it zeros, calibrates, and holds so you can remove and read the measurement. Worth the $30

Magnetic Digital Angle Gauge

 

[OregonLC]

Good tool reference. Thanks!

 

[natehack]

Well, just found this thread after thinking; "I want to eliminate the vibes/hum/throbbing from our family hauler". I just replaced ALL (except the lateral link) the rear suspension components and the vibe/throb is still there. Only have a slight lift with the 2865's I put on.

Maybe I should start playing around with the pinion angle a bit, see if that solves some noise. I have adjustable rear lower links.

Maybe I'll just continue to be the slooooooow guy in the Toyota... Good luck in yalls search for a solution. Thanks for the great ideas and advice.

 

[guerasfj60]

Here's my experience; installed MT up and low links, greased DS to alleviate the thunk. It did. I figured I'd change the 210K mi. spider joints.
Big mistake. As soon as I hit 50mph the infamous 50-60mph vibe was felt! I wasn't happy that the grease only exited two of the four caps. I also feel they are "tight". Tomorrow I will remove the DS, clean out splines and find a way to get grease in all four caps (I have an idea on how).

Either way, for me, the Ujoints are the reason for the 50-60 vibe. Reason I post here is because it also started a drone as if the rear wheel bearings are shot. His only started when I fubarred the ujoints.

Also contemplating the purchase of the entire rear DS assembly for 599+tax as I don't believe my chances of a proper ujoint install to have much chance of success.