Front end mystery noise after new front brake job w/stripped rotor bolt hole in hub

[dealmaker]

Had my independent mechanic here in the beach cities replace front AHC shocks, front pads and rotors, all OEM.
In the process he stripped out one of the holes in the left front hub, and had to remove it, heli-coil it, and added that extra work/part to my bill : (.
I'm assuming it was one of the holes where the brake rotor is attached to the hub with bolts. Is this a common fail item?

Since then, I've noticed a sound, sort of a whining, that seems to come from that left front end. Sound seems to have a "warble" that increases/decreases with speed, mostly noticeable over 35 mph, and is more apparent under acceleration/load than when coasting.

I'm trying not to be pissed about the stripped hub hole because in my mind its likely their fault for misusing air tools, but I'm OCD and that kind of crap annoys the hell out of me. To be fair, they did offer me the option of heli-coil or new hub, but as it was late in their work day (a Saturday) and they're closed the next two days and I needed the LX back for a road trip, I chose helicoil, based on their guidance that it shouldn't affect anything.

I'm going to bring it back there to have them access, but would like to have somewhat of an idea what the issue might be before then. My guess is bearings-related? Or is it possible that the helicoil would cause the hub to be out of balance enough to cause this?

'06 LX 470 with 137k miles. I'd driven it probably 750 mostly freeway miles since then and the sound hasn't changed.

TIY and yes, I was dumb to go for the $140 helicoil quick fix. In hindsight I should've used that opportunity to replace hubs and bearings/seals as they're all original.

Are there any 3rd parties selling complete OEM hub/bearing assemblies already put together that can be used, like what Blue Pit Bearings does with the 4Runners/GXs?

 

[jsloden]

Could honestly be a number of things. Were the ahc shocks leaking? not really any point in replacing them unless they are. They don't really work like normal shocks that wear out. The bolt that was stripped could be a number of different bolts. It sounds like you're probably right though. It's probably one of the rotor to hub bolts. It that's the case it shouldn't be a huge deal to use helicoil. The noise you're hearing sounds like it could possibly be the bearings. It is possible that they might be over-tightened. If it only makes the noise under braking it would be something brakes related; hub, rotor, pads, etc... If it makes it all of the time I would assume bearings or hub.

 

[dealmaker]

Could honestly be a number of things. Were the ahc shocks leaking? not really any point in replacing them unless they are. They don't really work like normal shocks that wear out. The bolt that was stripped could be a number of different bolts. It sounds like you're probably right though. It's probably one of the rotor to hub bolts. It that's the case it shouldn't be a huge deal to use helicoil. The noise you're hearing sounds like it could possibly be the bearings. It is possible that they might be over-tightened. If it only makes the noise under braking it would be something brakes related; hub, rotor, pads, etc... If it makes it all of the time I would assume bearings or hub.

Yes, the front AHC shocks were the original shocks and were weeping / leaking pretty bad, so I opted to replace.
Gonna bring it back to the mechanic Friday and see what they say about the mystery noise.

 

[ramangain]

Snatch a digital copy of the FSM and give it to them on a USB stick. Insist they must follow the FSM step by step starting with setting the 1st spindle nut torque and checking pre-load with the fish scale through the step of torquing the hub flange bolts. The fish scale should cost them $20, or buy it yourself and keep it afterwards. If they didn't regrease the bearings before reinstallation and they now grumble, that's on them.

 

[dealmaker]

Snatch a digital copy of the FSM and give it to them on a USB stick. Insist they must follow the FSM step by step starting with setting the 1st spindle nut torque and checking pre-load with the fish scale through the step of torquing the hub flange bolts. The fish scale should cost them $20, or buy it yourself and keep it afterwards. If they didn't regrease the bearings before reinstallation and they now grumble, that's on them.

Thanks so much for this. I'm at a loss when discussing with them because I know so little about this part of the front end, and I think they're getting sick of me. Their predominant customers are rich people, most of whom are on-road only, and likely not sensitive to changes in minor vibrations/sounds.

I'll look for a copy of the digital FSM but they should already have it, and the scale I would think. They are a well-established indy Lexus/Toyota shop in my area, operating out of an amazing new building.

 

[dealmaker]

UPDATE: Took it back to the shop that did the initial repairs. As I suspected, it was the front left wheel bearings.

They didn’t follow the FSM…I asked. Owner said at this point they’ve done so many (he and his #1 tech), that they go by feel and don’t follow FSM . Quoted me $350 to replace both bearings and seal on that one corner. I passed. Kind of pissed as I think this is on them since there were no issues when I dropped the LX off for the initial repair and it was there when I picked it up. They probably f’ed up the install and the bearing got damaged. They tried to put it back on me…maybe I hit something or whatever. I get it. It’s a 15 yr old ride w/137k miles. Still, considering I own 4 Toyotas and have been going there 11+ yrs I’m put off by their trying to put the blame on me.

I’ll probably tackle this myself. I watched a couple videos. Doesn’t look like rocket surgery.

 

[ramangain]

UPDATE: Took it back to the shop that did the initial repairs. As I suspected, it was the front left wheel bearings.

They didn’t follow the FSM…I asked. Owner said at this point they’ve done so many (he and his #1 tech), that they go by feel and don’t follow FSM .

What horse$hit! Just get a tub of grease, 54mm socket from Amazon, and then fish scale, snap ring tool, and wheel bearing kit from Cruiser Outfitters. A good torque wrench is needed too.

Trusting you've told the accurate, unbiased story, you may want to improve your DIY skills and work on moderate maintenance yourself. I'm sure there are locals who can help too in this community.

 

[dealmaker]

What horse$hit! Just get a tub of grease, 54mm socket from Amazon, and then fish scale, snap ring tool, and wheel bearing kit from Cruiser Outfitters. A good torque wrench is needed too.

Trusting you've told the accurate, unbiased story, you may want to improve your DIY skills and work on moderate maintenance yourself. I'm sure there are locals who can help too in this community.

Thanks, yeah, I'm a straight shooter and have no problem assigning fault to me if I see any. Only fault I can see on my side of the equation is last front bearing repack was done 57k miles previously, by same shop....almost 2X the recommended miles interval. My bad for letting that slide.

I'm for sure going to do this myself and already lining up parts and a few of the specialty tools that I don't already have or have access to. I was previously gearing up to do new LCAs, CVs, bearing/hub assemblies for my 4Runner in a couple of weeks, so the LX front bearings look fairly easy in comparison. I've been perusing MUD threads for a few hours last night and this AM. OCD can be a curse.

BTW, this guy has a recent youtube on 100 series front bearing replacement.... posting it here for future reference...looks like a solid how-to (I've since deleted the video and refer to @2001LC's videos).

 

[2001LC]

Likely someone cross threaded rotor mounting bolt in wheel hub. Helico should be fine if done properly. Balance "shouldn't" be to much of issue. As very near same weight added as was removed.

Wheel bearings & races are likely just fine.

What I see occasionally, is rear hub oil seal installed backwards (metal hump outward is wrong). This "may" be what you're hearing!

Wrong: Metal hump of seal, is wearing away.

Correct. Seal's hump in facing large bearing. Seals flat metal side seats flush with back of wheel hub.

This is very very bad, and can create unsafe driving condition. Why? Well wheel bearings well be set way to loose, as metal to metal of seal create false resistance during preloading.. As wheel hub turns, the raised (hump) metal protion of seal wears. This cause wheel bearing to loosen more and more as metal of seal wears away. The wheel hub will then start wobbling on spindle. This can set off ABS skid control in even mild turns on HWY. Can also cause brake rotor to wobble/rub in/on caliper and damage itself, pads and caliper. If wobble bad enough, it may cause rotor disk to separate form rotor (picture is from mud). I've seen these seal installed wrong, along with wheel bearings not being locked in (locking washer installed wrong). In those cases wheel hub can come off, if rotor's disk detaches.

---------------------------------
I watch a little of above video. During disassemble, it is best to NOT tap on hub flange, unless you plan on replacing it. Tapping on the side of hub flange, can warp the cone washer hole and or matting surface of flange to hub (water leak). Best to just hit studd using brass dowel or brass hammer.

Tips:
Lube axle needle bearing & brass bushing at each wheel bearing service ( each 30K miles).
Use a spring scale (fish scale) to set breakaway perload. (in video he has set wheel bearing way to loose)
Clean rotor disk surfaces, before installing hub flange. (Wheel hub spins freely.)
Replace hub flange nuts or use blue loctite on threads.
Replace snap ring using proper thickness to obtain a gap of less than 0.20mm (do not reuse snap rings, even if proper thickness), while axle pulled out and grease settled.

Here was the most difficult cone washer I had ever removed. Someone used FIPG on hub flange gasket, gluing hub flange and cone washer in

This is proper procedure for removing cone washers. Usually takes about 3 to 5 hits per stud. No heat or penetrating oil usually needed.


Here is how I do these days. So fast and easy with my brass tipped chisel. Love it!

 

[dealmaker]

Likely someone cross threaded rotor mounting bolt in wheel hub. Helico should be fine if done properly. Balance "shouldn't" be to much of issue. As very near same weight added as was removed.

Wheel bearings & races are likely just fine.

What I see occasionally, is rear hub oil seal installed backwards (metal hump outward is wrong). This "may" be what you're hearing!

Wrong: Metal hump of seal, is wearing away.View attachment 2801553
Correct. Seal's hump in facing large bearing. Seals flat metal side seats flush with back of wheel hub.
View attachment 2801552
This is very very bad, and can create unsafe driving condition. Why? Well wheel bearings well be set way to loose, as metal to metal of seal create false resistance during preloading.. As wheel hub turns, the raised (hump) metal protion of seal wears. This cause wheel bearing to loosen more and more as metal of seal wears away. The wheel hub will then start wobbling on spindle. This can set off ABS skid control in even mild turns on HWY. Can also cause brake rotor to wobble/rub in/on caliper and damage itself, pads and caliper. If wobble bad enough, it may cause rotor disk to separate form rotor (picture is from mud). I've seen these seal installed wrong, along with wheel bearings not being locked in (locking washer installed wrong). In those cases wheel hub can come off, if rotor's disk detaches.
View attachment 2801550
View attachment 2801551

---------------------------------
I watch a little of above video. During disassemble, it is best to NOT tape on hub flange, unless you plan on replacing it. Tapping on the side of hub flange, can warp the cone washer hole and or matting surface of flange to hub (water leak). Best to just hit studd using brass dowel or brass hammer.

Tips:
Lube axle needle bearing & brass bushing at each wheel bearing service ( each 30K miles).
Use a spring scale (fish scale) to set breakaway perload. (in video he has set wheel bearing way to loose)
Clean rotor disk surfaces, before installing hub flange. (Wheel hub spins freely.)
Replace hub flange nuts or use blue loctite on threads.
Replace snap ring using proper thickness to obtain a gap of less than 0.20mm (do not reuse snap rings, even if proper thickness), while axle pulled out and grease settled.
View attachment 2801576
Here was the most difficult cone washer I had ever removed. Someone used FIPG on hub flange gasket, gluing hub flange and cone washer in

This is proper procedure for removing cone washers. Usually takes about 3 to 5 hits per stud. No heat or penetrating oil usually needed.


Here is how I do these days. So fast and easy with my brass tipped chisel. Love it!

Many thanks for your insights and expertise, very much appreciated. I was about to drop close to $500 for new hub assembly w/bearings and all new cones, washers, nuts, clips, axle nuts, etc. for that one side. However, based on your opinion, I'll check the wheel for play, then start off with a removal/reinstall using same bearings and the repaired hub if the helicoil job wasn't a hatchet job. Spring gauge fish scale has been ordered.

What are the odds that the breakaway pre-load falls in spec 9.5-15 lbs at factory axle nut torque spec of 43 ft lbs.? It sounds like having breakaway preload in spec is more critical than 1st axle nut torque spec based on other threads/posts I've read? I think I saw in another thread that on one LC you' ended up going up to 78 ft lbs on 1st nut to get the breakaway preload in spec? I may be confused there,...been reading thru a lot of threads! If the goal is to establish breakaway preload in spec over 1st nut torque being in spec, should 2nd nut torque remain in spec at 47 ft lbs? Or should it match 1st nut torque spec. Last question... breakaway preload is tested simply by hooking top lug and pulling in direction of rotation to measure effort it takes to get wheel to turn? Sorry for all my wheel bearing noob questions!

 

[2001LC]

"First nut" or inner 54mm nut, is called the adjusting nut. Outer nut, is called lock nut.

Adjusting nuts torque, is incidental to breakaway preload. Which is, just pulling on spring scale hooked to a wheel stud. FSM states something like 57in-lbf (inch), which is starting point after grease settled by torquing adjusting nut to 45ft-lbf, spinning hub and back off adjusting nut.

With new bearings, with a breakaway preload at ~12lb of pull. Torque incidentally comes in at ~47ft-lbf most always for me. But that me; cleaning hub and bearing spotless, using same grease (M1) at about same temp, pulling on spring scale at same angle (parallel to vehicle). Turn wheel hub in direction of travel only.

Lock nut is always set to 47" ft-lbf. (Best to always use new lock washer)

 

[dealmaker]

Finished wheel bearing replacement on the side with the howl.

And...the mystery noise persists. Drove 50 miles on the freeway and exactly same symptoms....happens under acceleration load, etc. noticeable at 35+mph.

I feel confident I did the job right, new OEM bearings/races/parts from Cruiser Outfitters, M1 grease, breakaway preload avg 12# at 55 ft lbs torque on adjusting nut.

I attempted to grease the spindle bearings and used an older M1 grease cartridge I already had in my grease gun and I could not get it to go in and work thru to other side. The consistency of that grease was pretty thick and I used the cheapie PVC cap tool. The end of the axle pushes in, but I couldn't get the grease to flow thru to the back side., and probably not even in at all as it kept forcing its way out around the PVC cap/locking nut point-of-contact. I changed to a brand new M1 cartridge and still couldn't get it thru. I had the PVC cap held against the lock nut very tightly. So....feeling kinda defeated by that. Was hoping I could get the grease thru to the other side and know needle bearings were adequately lubed, to rule out the noise coming from there. Suggestions?

 

[peacesells63]

did you check torque on the rotor bolts when you had the hub apart?

 

[peacesells63]

That sound is typical of a bent/warped rotor. There are only 5 bolts holding the rotor on, if they are not torqued properly or if there is an imperfection in the seating surface, it causes them to wobbly and contact the pads. Do you have access to a dial indicator with a magnetic base?

 

[dealmaker]

did you check torque on the rotor bolts when you had the hub apart?

I did not. My independent Lexus/Toyota mechanic in Hermosa Beach was the one who stripped a hole in the hub while replacing the rotors, and he was the one who helicoiled that hole. I probably should've separated rotor from hub and checked the work where the surfaces mate. I guess that will be my next step. I regret not just buying a new hub. That will probably be my next step. Time to look up rotor bolt torque specs.

That sound is typical of a bent/warped rotor. There are only 5 bolts holding the rotor on, if they are not torqued properly or if there is an imperfection in the seating surface, it causes them to wobbly and contact the pads. Do you have access to a dial indicator with a magnetic base?

Interesting. I woke up at 3AM and started to wonder if the new rotor, replaced by my mechanic <1,000 miles ago, could possibly be defective.
I have a friend who works at a huge metal fab shop and will ask him if he has a way to check this out. I'm pretty sure he does.

I wish I could just find a competent mechanic who could do this, I'm short on time these days.

And I'm still flummoxed by the inability to push grease in to the spindle/needle bearings from the axle shaft, so I was concerned maybe those are dry.

 

[2001LC]

It may be worth another opinion as to where & what sound is. Take it to dealership, and just say you hear a new sound, you think is up front, happens on HWY and underload. Don't tell them it's been worked on.

"Sound seems to have a "warble" that increases/decreases with speed, mostly noticeable over 35 mph, and is more apparent under acceleration/load than when coasting"
It's been my experience, that most bearings will make oscillating (warble) sound when coasting also. But the front driveshaft CV bearings, may be pronounced underload.

Run-out dial gauge:
Definitely a good idea to check run-out of the rotors, as @peacesells63 suggested. Which book (FSM) procedure is to run-out all new rotor and mark ortenation in best position (least run-out within spec). Typically new OEM rotors are within spec. Typically if out of spec, procedure is then to machine turn rotor. Which Dealership will have and OTV lathe. But if that one found "out", I'd have concern as to helico, possibly not flush with inner hub.

You can also inspect the rotor bolts, kind of! In that when torqued in, they all protrude out the front of hud the same distance (as far as eye can judge).

Although if rotor out of spec, I'd think you'd hear sound at all times, not just higher speeds and underload. Also in typical so called "warped rotors" you'd likely have steering wheel pulsation, when braking! Pulsation is often not felt until rotors and pad overheated.

Here video of warped rotors effect on steering wheel. Notice driver is using brake to control downhill speed (which is very bad driving habit).

 

[dealmaker]

It may be worth another opinion as to where & what sound is. Take it to dealership, and just say you hear a new sound, you think is up front, happens on HWY and underload. Don't tell them it's been worked on.

"Sound seems to have a "warble" that increases/decreases with speed, mostly noticeable over 35 mph, and is more apparent under acceleration/load than when coasting"
It's been my experience, that most bearings will make oscillating (warble) sound when coasting also. But the front driveshaft CV bearings, may be pronounced underload.

Run-out dial gauge:
Definitely a good idea to check run-out of the rotors, as @peacesells63 suggested. Which book (FSM) procedure is to run-out all new rotor and mark ortenation in best position (least run-out within spec). Typically new OEM rotors are within spec. Typically if out of spec, procedure is then to machine turn rotor. Which Dealership will have and OTV lathe. But if that one found "out", I'd have concern as to helico, possibly not flush with inner hub.

You can also inspect the rotor bolts, kind of! In that when torqued in, they all protrude out the front of hud the same distance (as far as eye can judge).

Although if rotor out of spec, I'd think you'd hear sound at all times, not just higher speeds and underload. Also in typical so called "warped rotors" you'd likely have steering wheel pulsation, when braking! Pulsation is often not felt until rotors and pad overheated.

Here video of warped rotors effect on steering wheel. Notice driver is using brake to control downhill speed (which is very bad driving habit).

Thank you for this. I will follow your advice and take it to my local dealer to check it out. Myself and my neighbor did look at the rotor bolts and nothing stood out. My neighbor is mechanically inclined and supervises a huge metal fab shop and operates lots of machinery, mills, lathes, etc and has a good eye for this stuff. If dealer has no clue then I'll have my neighbor help me check run-out.

Re warped rotors, last weekend on a road trip I discovered the hard way that one of my 4Runners (the '03) that I don't usually drive, and hasn't been freeway-driven in a year, had warped rotors...very unnerving feeling when braking at 80mph! Ended up taking it to a Toyota dealer at our trip destination to do new pads/rotors...$600...ouch but didn't have the luxury of DIY as we were on the road. The LX has zero braking issues at freeway speeds...just the dang warble sound. Thanks again guys, your input means a lot to me!

 

[dealmaker]

Had a chance to clean up the parts I swapped out. This was the wear on the thrust washer.
Probably original, and flipped over a few times....the scoring lines up with outboard bearings, but you can clearly see marks from adjusting nut, too.
The snap ring has light partial scoring on it from axle shaft. Previous snap ring was E, I put in largest that would fit, which is D. I'll pull the wheel after another 50 miles and see if I can pull axle shaft out further and fit larger in there after everything settles, assuming nothing else needs to be R&R'ed in there. I'm still annoyed I couldn't work any grease in to the spindle using the PVC cap method. I guess I'll look for a needle for my grease gun and try from behind.

 

[dealmaker]

Still trying to sort it out, haven't yet checked the (new) rotors runout. Definitely no pulsating when braking so I'm feeling like the problem isn't with the rotors. Still, I may check runout this weekend if my neighbor is available to help.

Regarding the cone studs (bolts?), when replacing the cones/washers/nuts, I noticed some of the studs or bolts would rotate while others did not. Is that anything I need to be concerned with? When I torqued down the new nuts/washers/cones those "loose" ones anchored down and tightened.

I'm still slowly chasing the mystery noise. Haven't taken it to a new mechanic or dealer yet, but I did grease the spindle bearings using the LCP method. I also reviewed and spreadsheeted all my service records. It looks like when the front brake pads/rotors/wheel bearings work was done in August, that was the first time the new-in-2019 Michelin LTX tires were rotated. . So 15k miles on new tires before rotation . I own that even though my likely former mechanic told me they don't rotate by mileage, only by wear. No odd wear patterns visually noticed, but when I had the FDS corner (where the noise seems to come) from up on a jackstand last week, just barely off the ground, as I’d rotate the tire it would very lightly rub the ground in one area, as though the tire was slightly out-of-round. I took to Americas Tires last week to inspect and balance. They told me they can’t assess if a tire is out of round, all they can do is rebalance, which they did for all four. The mystery sound is still there. I would think that after driving 1,500 miles since the rotation, and when the mystery noise first started, that any tire-related noise would've been reduced to zero? I could rotate them back next weekend to see if the mystery noise goes away. Frustrating….

 

[Slickspawn]

@dealmaker did anything ever come of this? Solved?