Rhythmic hum: Bearing replacement/repack or driveline?

[Super77]

I’m troubleshooting two symptoms that I’m connecting to wheel bearings:

1. A quiet, rhythmic growl that increases with speed
2. Looseness in the front DS wheel when wiggled at 12 and 6 o’clock.

Truck has 143K, lived a sedate suburban life, gentle climate, rarely offroaded, no mods. Paperwork suggests no bearing service ever done, but the spindle caps show signs of prior removal.

Q: I’ve got the FSM and ‘Mud writeups for front bearing replacement, but I also understand that Toyota recommends a 30K interval inspection and repack? Given that a repack involves much of the replacement labor, why not just replace (other than saving the part cost)? Or is a repack/grease/re-tension really that much less work than replacement?

Q: I’m uncertain of the source of the rhythmic growl. My brains tells me DR front since I know that wheel is a little loose, but my ear tells me it’s coming from the rear. I’m thinking: fix the front wheel first (since we know it’s loose and that’s not good), then check again for the noise. What are some common rear end rhythmic growls and their troubleshooting order?

 

[nissanh]

In both cases you have to do almost equal amount of labor. The bearings needs extra time for outer race and grease seal installation. I usually inspect for any gouges on the surfaces on needle rollers and races. Since you are getting a growling sound, why not install new bearings just to make sure it is eliminated from question. Inspect wheel studs and this is a great time to replace those if needed.

I think there is a tool that can be use to force grease past the outer bearing into the hub if you want just to grease and tighten the 54 mm bolt and check for the sound.

Unless those front roller bearings are ran with some play, from my experience, the bearings really last a very long time at least to about 400K miles or more.

 

[Trunk Monkey]

Only difference in labor is hammering the races out of the hub and installing the new ones. Cost is a bigger difference, hub kit vs tub of good grease.

I just inspect what's in there and have two sets of Cruiser Outfitters hub kits on hand in case I need to replace due to scoring or discoloration, which I've never found either.

You don't say if your noise is new, but common one this time of year is the t-case as temps cool off.

 

[Nardulli]

Your question isn’t really a question. Seems like you already know what you need to do. Follow the FSM and upon disassembly you will know if replacement is needed. If not, then clean and repack and set your preload exactly as the FSM shows you. Those OEM bearings and races are top quality. With proper care they’re good for more miles than you’ll likely ever pit on it.

 

[Super77]

I think there is a tool that can be use to force grease past the outer bearing into the hub if you want just to grease and tighten the 54 mm bolt and check for the sound.

I’m aware of a tool that forces grease into new bearings. Link to the one you’re thinking of?

You don't say if your noise is new, but common one this time of year is the t-case as temps cool off.

I just recently noticed it, may have simply not been paying attention before. I’ve only had the rig for half a year. The tcase fluid was just changed.

Your question isn’t really a question. Seems like you already know what you need to do. Follow the FSM and upon disassembly you will know if replacement is needed.

Agreed, but I still like to check the ‘Mud hive mind .

What am I looking for on the bearing? Heat marks? Scored races? Deformed needles? Should I degrease the bearings and full regrease from scratch?

Also, the FSM recommends the “fish scale” method to preload tension when reassembling. Do we concur with that or is there a better method?

 

[Malleus]

The bearing cup, rollers and cone should be bright and shiny with no discoloration or surface deformation whatsoever. The cage should also be intact with no visible deformation.

Yes, you have to clean the bearings to inspect them. Use mineral spirits to remove the bearing grease and alcohol to remove the mineral spirits. There is a popular belief that you should never use compressed air to clean bearings. I do it all the time and I don't have bearings fail. I believe the reason for this bit of wisdom is that most compresed air systems is not sufficiently dried, and water on bearings is a recipe for bearing failure. Even if your compressed air isn't 100% dry, you can still use it if you rinse the bearings in alcohol immediately prior to packing them. Once packed, they're good for the life of the grease.

Bearing packing tools that are used to "pack" bearings that are installed are voodoo. Use them at you own risk.

I use the fish scale, others seem to believe it's voodoo. There is only one way to positively know that the bearings have been seated and preloaded properly, and it can't be used with wheel bearings. Therefore, the bearing preload procedure has to be "measured" indirectly. There has been proven to be a direct correlation between the rolling friction of properly packed wheel bearings and preload. Ignore it if you want, but there is no method that's any better, and quite a few that are worse.

Whichever method you use, pay very close attention to the procedural differences between measuring preload on new and used bearings. It is not the same.

 

[Nardulli]

Malleus is spot on. We have a parts washer so that makes it simpler. You want all degreaser out of the bearing - even a little ruins the viscosity of the grease. After you torque the hub and work it in both directions you back it off and follow the procedure. I can’t recall the spec - something like 12 pounds force?

 

[Super77]

One more: I was planning to have new snap rings on hand, but Uncle T sells them in 6 different thicknesses. Should I buy the same thickness I have currently, or is the correct thickness determined by the stack-up of any new parts I install?

I assume the different snap ring thicknesses are to cancel out any tolerance creep in the full hub “hamburger.”

 

[Trunk Monkey]

2001LC has a huge hub rebuild thread, I'd check that out, he explains in great detail the snap rings. Short of it is, if I'm repacking, I use the same one, not even a new one, never had an issue. If I'm replacing the bearings and races I have 2 of the 6 pack sets on hand, again from Cruiser Outfitters.

 

[Malleus]

I buy only the thick ones, and grind them down to size. I rarely use a different thickness, but you are correct, there are varying thickness to compensate for the stack up. They aren't the critical component, the nut(s) is(are). They're just there to take up slack.

 

[Trunk Monkey]

For the number of them that get posted about here that pop off the end of the CV and then causes CV and flange spline damage, I'd say having the right thickness is pretty critical. Good groove on the CV is as well.

 

[nissanh]

I follow the instructions in this video to set the hub bearing.

 

[2001LC]

Wheel bearings. Replace or not:

I start by wiping, races clean. So I can inspect them. If they fail inspection, I replace wheel bearings and races. If races pass inspection. I clean and inspect wheel bearings. Average life, for properly cared for wheel bearings. Based on calculations made by @abuck99, using Timken data. Is, 250K miles. I do find this to be average, as well! But if wheel bearings properly care for, from day one. They can go much longer, as they're very robust. They're just not going to be to Timken wear spec.

I find, that good worn-in wheel bearings. Will result in a higher torque (65 to 80ft-lbf) on adjusting nut, to achieve the 9lb to 15lb (12.5LB is my target, 15lb in built rig) of breakaway preload. Whereas trashed bearings, result in very low torque (less than 45ft-lbf) to achieve the same breakaway preload (BPL).
Note: Temperature of grease, spindle and wheel bearings. Affects breakaway preload. Below ~58f we start seeing a false high reading on fishscale as we set BPL. Below ~33F, we get a useless BPL reading.

Grease. Should stated "wheel bearing grease". They are, high speed greases.


Snap ring (hub flange):

Replacing snap ring, insure, tight grip in/around axle groove. Which is import, otherwise we risk damaging axles snap ring groove.

The factory snap ring is 2.2MM (E) thick. Less than 1% of time, do I use the E. Even when all parts that affect gap, are new/replaced.
70% of time I use 2.4mm (D) to achieve proper gap (hub flange to snap ring) of less than 0.20mm.
28% of time I use 2.6mm (C).
1% of time 2.8mm (B).

If 2.8mm doesn't bring down gap, to less than 0.20mm. I need to replace other parts, to achieve a proper snap ring gap. Even when R&R all parts that affect snap ring gap, are replaced. I still, mostly need, the 2.4MM (D) thich snap ring.

Parts that affect gap other than snap ring, in order of most common need be replaced:

1. FDS (axle snap ring groove, increased/damage)
2. Hub flange (face of hub flange where snap ring rides, wear due to excessive pounding from excessive gap and loose wheel bearings)
3. Brass bushing (wear item for snap ring). This is wears, which why we need to set gap every wheel bearing service.
4. Large wheel bearing.
5. Knuckle weare. ( Where large wheel bearings race butts up) This is result, of loose wheel bearing.

Other non-reusable parts:

• Seal in back of wheel hub.
• Hub flange gasket.
• Grease cap, is non reusable. Reuse increase chance of water entry.
• Lock washer is non reusable.
• Hub flange nuts. Are listed in FSM as non reusable. But we can reuse; Provided condition of threads is good (not worn or stretched, to point of excessive loose fit and play), and we use a threads sealer. I use Blue (medium) thread sealer. We use the factory torque spec of 24ft-lbf. We do not reduce torque, 20% as would when lubing threads. Since factory nuts, are lubed (thread sealer in them). The factory has already account for the threads being lubed.

Good time to note:

Front brake caliper bolts are not factory lubed. Torque spec is 90ft-lbf, dry threads. It's very good idea to use a medium thread sealer here. Which we then reduce torque ~ 20%., to 72ft-lbf.

 

[Nardulli]

For what it's worth, I always use this grease:

Amazon.com: Timken GR224TUB Grease : Automotive

Amazon.com: Timken GR224TUB Grease : Automotive

www.amazon.com

And this 54mm socket comes with what you need:

Amazon.com: YANGCAN Hub Socket Nut Kit 1/2" Drive 54mm Compatible with Landcruiser, Hilux 4x4, N-issan Patrol : Automotive

Buy YANGCAN Hub Socket Nut Kit 1/2" Drive 54mm Compatible with Landcruiser, Hilux 4x4, N-issan Patrol: Tire Repair Tools - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

It's a cheap socket but for the number of times you might need it, it does the job.

 

[Super77]

How do we feel about the Timken bearing sets? Toyota OEM bearings I see are marked Timken.

 

[uHu]

... Q: I’m uncertain of the source of the rhythmic growl. My brains tells me DR front since I know that wheel is a little loose, but my ear tells me it’s coming from the rear. I’m thinking: fix the front wheel first (since we know it’s loose and that’s not good), then check again for the noise. What are some common rear end rhythmic growls and their troubleshooting order?

A "growl" sounds more like a spindle bearing sound than a wheel bearing sound. Depending on the quality of the growl. One possibility is that the shaft is riding on the brass bushing inside the spindle, which gives a quite specific growl.

 

[abuck99]

Timken

How do we feel about the Timken bearing sets? Toyota OEM bearings I see are marked Timken.

Timken and Koyo are OES, can’t go wrong with either. Fwiw- Timken came from the factory on my 05.

 

[Super77]

A "growl" sounds more like a spindle bearing sound than a wheel bearing sound. Depending on the quality of the growl. One possibility is that the shaft is riding on the brass bushing inside the spindle, which gives a quite specific growl.

I’m tackling the loose wheel issue first, since I believe that’s likely a loose or worn wheel bearing - correct me if I’m wrong.

If the growl goes away: both problems solved.

If not, I’ll investigate next likely candidates. Tell me about the spindle bearing?

 

[Super77]

Wheel bearings. Replace or not:

I start by wiping, races clean. So I can inspect them. If they fail inspection, I replace wheel bearings and races. If races pass inspection. I clean and inspect wheel bearings. Average life, for properly cared for wheel bearings. Based on calculations made by @abuck99, using Timken data. Is, 250K miles. I do find this to be average, as well! But if wheel bearings properly care for, from day one. They can go much longer, as they're very robust. They're just not going to be to Timken wear spec.

I find, that good worn-in wheel bearings. Will result in a higher torque (65 to 80ft-lbf) on adjusting nut, to achieve the 9lb to 15lb (12.5LB is my target, 15lb in built rig) of breakaway preload. Whereas trashed bearings, result in very low torque (less than 45ft-lbf) to achieve the same breakaway preload (BPL).
Note: Temperature of grease, spindle and wheel bearings. Affects breakaway preload. Below ~58f we start seeing a false high reading on fishscale as we set BPL. Below ~33F, we get a useless BPL reading.

Grease. Should stated "wheel bearing grease". They are, high speed greases.


Snap ring (hub flange):

Replacing snap ring, insure, tight grip in/around axle groove. Which is import, otherwise we risk damaging axles snap ring groove.

The factory snap ring is 2.2MM (E) thick. Less than 1% of time, do I use the E. Even when all parts that affect gap, are new/replaced.
70% of time I use 2.4mm (D) to achieve proper gap (hub flange to snap ring) of less than 0.20mm.
28% of time I use 2.6mm (C).
1% of time 2.8mm (B).

If 2.8mm doesn't bring down gap, to less than 0.20mm. I need to replace other parts, to achieve a proper snap ring gap. Even when R&R all parts that affect snap ring gap, are replaced. I still, mostly need, the 2.4MM (D) thich snap ring.

Parts that affect gap other than snap ring, in order of most common need be replaced:

1. FDS (axle snap ring groove, increased/damage)
2. Hub flange (face of hub flange where snap ring rides, wear due to excessive pounding from excessive gap and loose wheel bearings)
3. Brass bushing (wear item for snap ring). This is wears, which why we need to set gap every wheel bearing service.
4. Large wheel bearing.
5. Knuckle weare. ( Where large wheel bearings race butts up) This is result, of loose wheel bearing.

Other non-reusable parts:

• Seal in back of wheel hub.
• Hub flange gasket.
• Grease cap, is non reusable. Reuse increase chance of water entry.
• Lock washer is non reusable.
• Hub flange nuts. Are listed in FSM as non reusable. But we can reuse; Provided condition of threads is good (not worn or stretched, to point of excessive loose fit and play), and we use a threads sealer. I use Blue (medium) thread sealer. We use the factory torque spec of 24ft-lbf. We do not reduce torque, 20% as would when lubing threads. Since factory nuts, are lubed (thread sealer in them). The factory has already account for the threads being lubed.

Good time to note:

Front brake caliper bolts are not factory lubed. Torque spec is 90ft-lbf, dry threads. It's very good idea to use a medium thread sealer here. Which we then reduce torque ~ 20%., to 72ft-lbf.

Awesome! I hear you have a long thread in this topic, @2001LC ?

 

[Trunk Monkey]

We feel great about Timken. Or Koyo.