Rear Wheel Bearing Vibration?

[OregonLC]

Thanks Dan. The guy I used is a local 'expert'. Gears has been his only trade for the last 20 years. He has work subbed to him from the dealers around town. Doesn't mean he didn't set them up incorrectly by any means. Plan this week is to go to a different shop as a second opinion. FWIW they were flawless for the first two seasons.

It will be going to either Land Cruisers NW (downtown Portland) or Land Cruiser Specialties (Oregon City). If anyone has experience with one or both I'm all ears.

 

[spressomon]

Well, maybe you need to pull the rear 3rd and have a looksie. If no other changes then it seems plausible its a wearing part/parts; just a guess. Fortunately the rear 3rd is a relatively easy thing to remove (2-guys and/or lift & cradle make it easier).

 

[AKLX470]

I have been having the same issie with the vibration and all the techs I have used maintain that everything is fine. Uh no. New, balanced driveline, front WBs, CVs and still vibration at 60-70. Havent had the front driveline looked at but i dont feel any vib in the steering wheel, mainly in my seat. However, looking at the front Diff, there appears to be oil remnants but no pronounced leaks. I have an LX converted to LC suspension with a 2.5" HD lift from OME. Any ideas or suggestions aside from what i just read would be appreciated!

 

[spressomon]

AKLX470, did your problem develop similar to Dennis' (OregonLC) or has the vibe always been present (probably after a lift including a diff drop). Also what is your front suspension height measured vertically (level surface) from the center of the hub straight up to the lower lip of the front fender? If this is too high you could be getting a CV induced vibration due to the steeper CV angles associated with too much suspension height.

Its been tossed around in different circles but a diff drop can put the front driveshaft on a flat plane which is not typically the orientation u-joints need to be positioned. I've long suspected the diff drop being a contributor to drive line vibes, as minor as they are, on mine as before the lift and diff drop it was butter smooth (4.88's were added at the same time ...).

I fabbed adjustable rear upper control arms and played around with pinion angles and was able to tune most of my vibe out. But, by removing the front drive shaft the driveline is factory smooth. Of course drive-shafts are notorious vibe/noise magnifiers and just because the vibes went completely away by removing the front drive shaft it doesn't necessarily point at a front drive shaft problem.

Lastly, driveline experts operate as much from the "art" world as they do the "science" world. And good ones are as scarce as hens teeth. But that doesn't stop most if not all driveline shops from loud casting they know more than anyone else ...

 

[AKLX470]

AKLX470, did your problem develop similar to Dennis' (OregonLC) or has the vibe always been present (probably after a lift including a diff drop). Also what is your front suspension height measured vertically (level surface) from the center of the hub straight up to the lower lip of the front fender? If this is too high you could be getting a CV induced vibration due to the steeper CV angles associated with too much suspension height.

Its been tossed around in different circles but a diff drop can put the front driveshaft on a flat plane which is not typically the orientation u-joints need to be positioned. I've long suspected the diff drop being a contributor to drive line vibes, as minor as they are, on mine as before the lift and diff drop it was butter smooth (4.88's were added at the same time ...).

I fabbed adjustable rear upper control arms and played around with pinion angles and was able to tune most of my vibe out. But, by removing the front drive shaft the driveline is factory smooth. Of course drive-shafts are notorious vibe/noise magnifiers and just because the vibes went completely away by removing the front drive shaft it doesn't necessarily point at a front drive shaft problem.

Lastly, driveline experts operate as much from the "art" world as they do the "science" world. And good ones are as scarce as hens teeth. But that doesn't stop most if not all driveline shops from loud casting they know more than anyone else ...

Very interesting! Yes, this mainly started with the suspension swap and Diff Drop. I will measure that distance youre referring to when i get in my garage this evening. That info is much appreciated considering no one knows what the heck it could be here in Anchorage. The CVs is what im thinking but i didnt think about the diff drop. It's been said it's necessary with the OME lift, can anyone confirm or deny this? Thanks again, i will be in touch with more info shortly

 

[SanDiegoCruiser]

Very interesting! Yes, this mainly started with the suspension swap and Diff Drop. I will measure that distance youre referring to when i get in my garage this evening. That info is much appreciated considering no one knows what the heck it could be here in Anchorage. The CVs is what im thinking but i didnt think about the diff drop. It's been said it's necessary with the OME lift, can anyone confirm or deny this? Thanks again, i will be in touch with more info shortly

I've been chasing a de-acceleration vibe for over a year which occurred after regearing to 4.88's and installing a front locker. I've Replaced both front & rear drive shafts and rear upper/lower control arms.

The new metal tech control arms helped a little but I still feel it when letting off the gas > 75 mph. I did try messing with the pinion angle when installing the new rear suspension parts but that didn't seem to make a difference.

Unlike Dennis, I can't reduce it by removing front or rear Drive shafts. I do have a diff drop that's been installed for years...

I just have decided to stop throwing $$ at it since it has not gotten worse over the past 5K plus miles.

 

[abuck99]

Looking at the video (very cool btw) of your driveshaft- Im seeing something at the pinion flange where it meets the 3rd maybe one side of the dust seal and flange is clean/shiny, making it look like it's wobbling ever so slightly. It's prob an optical illusion but it looks odd.

Another thing you might consider changing around is the driveshaft orientation- put the slip yoke end at the tcase. Change in rotating direction might make a small difference. I know the FSM for the 100 shows it pointing at the 3rd, but the 80s are opposite of that- the benefit: keeps slip yoke out of the mud, sand etc.

 

[OregonLC]

I could try that, however I've already swapped in a known good DS from our 04 (at least it doesn't vibe on that truck) with no change. On that vehicle, the rear DS is actually mounted reverse direct (slip yoke forward). This was a Lexus serviced vehicle for most of it's life prior to me so I'm not sure when it would have been turned around. Not a typical service item to remove. While it does keep it up a bit, it also allows gravity to work against the seal. Have no idea if this would be better or worse design.

The dust cover was me making room to get to the flange nuts. Had to persuade it a bit to get the box end of the wrench on. It's so light that it doesn't concern me. Sidebar question: what do folks use to get those nuts loose? FSM shows 78 lb-ft which is a lot for a little 14mm box/open. Throw air to the bolt head and hold the nut with the wrench? Seems backwards.

What does concern me a bit is the wobble in the main shaft just forward of the slip yoke. Watch the runout when starting from a complete stop.

 

[spressomon]

Dennis, this is the SnapOn tool I carry & use. Makes loosening driveshaft nuts/bolts a non-affair.

 

[AKLX470]

AKLX470, did your problem develop similar to Dennis' (OregonLC) or has the vibe always been present (probably after a lift including a diff drop). Also what is your front suspension height measured vertically (level surface) from the center of the hub straight up to the lower lip of the front fender? If this is too high you could be getting a CV induced vibration due to the steeper CV angles associated with too much suspension height.

Its been tossed around in different circles but a diff drop can put the front driveshaft on a flat plane which is not typically the orientation u-joints need to be positioned. I've long suspected the diff drop being a contributor to drive line vibes, as minor as they are, on mine as before the lift and diff drop it was butter smooth (4.88's were added at the same time ...).

I fabbed adjustable rear upper control arms and played around with pinion angles and was able to tune most of my vibe out. But, by removing the front drive shaft the driveline is factory smooth. Of course drive-shafts are notorious vibe/noise magnifiers and just because the vibes went completely away by removing the front drive shaft it doesn't necessarily point at a front drive shaft problem.

Lastly, driveline experts operate as much from the "art" world as they do the "science" world. And good ones are as scarce as hens teeth. But that doesn't stop most if not all driveline shops from loud casting they know more than anyone else ...

Sorry it took so long but measurements are 22.5 in the front and 23.25 in the rear. The fender to the hub that is

 

[spressomon]

^ I've had better overall success (steering, CV angles & subsequent durability/lifespan, torque steer, etc.) with 20-20.5". Since its so easy to adjust our t-bars you might try lowering the front and testing driving to feel the effect. Also, say you were to lower your static front suspension height, you would increase your relative caster #.

I can assure you, if you lower the front to 20.5-ish you will feel a difference. Now, whether that solves your vibe problem is open for debate . But other than an hour or so of your time what do you have to lose?!

 

[AKLX470]

^ I've had better overall success (steering, CV angles & subsequent durability/lifespan, torque steer, etc.) with 20-20.5". Since its so easy to adjust our t-bars you might try lowering the front and testing driving to feel the effect. Also, say you were to lower your static front suspension height, you would increase your relative caster #.

I can assure you, if you lower the front to 20.5-ish you will feel a difference. Now, whether that solves your vibe problem is open for debate . But other than an hour or so of your time what do you have to lose?!

Im open for anything, that i appreciate. I will try that for sure

 

[OregonLC]

So on referral I was directed to a driveline shop closer to home. Guy checked from the ground and says it's the slip yoke. Too little insertion and loose splines. Seem plausible?

The thing he can't explain (nor can I) is why the vibration goes away when I apply the handbrake when still under throttle. To the drive shaft this should just be like going up a hill. His explanation is that the added load is causing the splines to lock up. But the force on the splines is a factor of throttle (which is steady) not drum brakes. Nor does it explain why there is still vibration when the 04 shaft is swapped onto the 2000. No vibration when driving the 04.

As for the insertion depth, it's 20.5" at the rear. Hardly a major lift.

In the video, though, you can see a bit of wobble near the slip yoke when starting.

I feel like I have a bucket of questions with no clear answer right now. Vibe is getting worse, can now feel around 50. Almost hoping something will blow up. Before I set fire to it that is...

 

[abuck99]

The shops asesment seems as good a guess as anyone who's posted in this thread(fwtw).

To confirm plausibility, if you swapped the drive shaft around the drive direction would be rotating opposite and the splines would be mating on fairly fresh surfaces (unless you spent a lot of time driving in reverse)

Your rear height is nearly stock- and you have aftermarket springs if I recall. You must have a lot of extra weight on that rear axle.

 

[OregonLC]

I'm light right now with no tent, no water, and minimal gear. Deployed I'm 4K on the rear and 3.4K on the front. I'd guess probably 3.7K on it right now. I believe it's on 864s (?) or whatever the progressive rate OME springs are. And yes, it's fairly flat for a modified LC. The 35s are where I get my height.

 

[spressomon]

Progressive rate springs are OME 866. OME 864 is the next to the heaviest rate OME offers for 80/100; I have 864s on mine. When you're loaded for camping Dennis don't you find the softer section of the 866 coils completely collapsed? If OME hasn't reconfigured that spring that was my experience a decade ago with them.

 

[spressomon]

I can buy the loose splines but not insufficient overlap ... granted the 100-Series doesn't have a lot of spline overlap but I'm certainly higher rear lift than you are D and no overlap issue. Are your aftermarket rear control arms the same length as OEM/stock?

 

[OregonLC]

Haven't had any complaints with them. Ride quality is good. Honestly, haven't ever looked to see what the coils are doing. I looked into going to the heavier springs, however I'm quite happy with the ride height; I rub the garage door gasket as it is. Any additional height and I'd need to air down to come into the garage. Dang architectural door openings.

 

[OregonLC]

I can buy the loose splines but not insufficient overlap ... granted the 100-Series doesn't have a lot of spline overlap but I'm certainly higher rear lift than you are D and no overlap issue. Are your aftermarket rear control arms the same length as OEM/stock?

Should be very similar. Mine was the prototype vehicle for the MT 100 series links and I'm fairly certain that LT set them up to match factory length. The below is the exposed length of the slip yoke. Seem long to you?

Owner of the shop I took it to called me back later this afternoon and we talked at length. Very well versed gentlemen. I have confidence (or at least high hopes) that he will help to drive to resolution. It goes in on Monday and we have a specific plan to examine everything and dial out all flanges and hubs before we start spending money.

The thing that has me stumped is how the brake application is able to quell the vibration. His theory is that while it doesn't change load on the input side of the diff at all (constant throttle) but could possibly change the pinion angle as the brakes load up and wrap the axle forward. Lends credence to perhaps it being a shaft problem.

Slim chance it could be a bent axle (last year did see some heavy use of the truck) but that wouldn't likely disappear when the rear shaft was removed.

 

[OregonLC]

Progressive rate springs are OME 866. OME 864 is the next to the heaviest rate OME offers for 80/100; I have 864s on mine. When you're loaded for camping Dennis don't you find the softer section of the 866 coils completely collapsed? If OME hasn't reconfigured that spring that was my experience a decade ago with them.

BTW, I measured earlier today and I'm 20.5" in the rear and 20.25" in the front. What do you show for rear height? When you roll across scales what do you show for rear axle weight?