Rhythmic hum: Bearing replacement/repack or driveline? (2 Viewers)

[2001LC]

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

I've post on wheel bearing service, in many threads. Some can be found in my master thread link, found in signature line below. I've also short videos on key points. I don't have and end to end video, which would be very long.

Following every step in FSM, cleaning and restoring as needed. Takes time! It's very rare any shop can afford to take the time. Fewer, even know how or open the FSM to learn. Like taking the time or even know axle needle bearing & brass bushing need lubing. It is, very rarely ever done. Which is also required every 30K miles. Even when FDS (AKA: CV) replaced, most do not lube this area.

One thing I look at, once axle exposed. Is where needle bearing (AKA spindle bearing) rides on axle. The condition of axle, is a key clue, to health of needle bearing. Looking at needle bearing itself, is very difficult to make the call if good or bad. As @uHu mentioned above, "spindle bearing". Could well be your sounds. I've seen 100 series with ~350K miles, with supper service history at Dealership. With dozen of wheel bearing service in its history. But find the axle bearing and bushing, has never been lube. Most I find, still the factory grease. Needless to say, those needle bearings are shot.

Skipping needle bearing and bushing, while doing wheel bearing service. Will likely mean remove wheel hub again. Since the axle can only be seen, when either knuckle is pulled off or FDS is removed. When doing a wheel bearing service. It is the best use of time, to remove the steering knuckle while in there. Coming back to do later, is doubling labor time.

This was a new FDS with ~about 2K miles. That mild scoring on axle, was the clue, axle needle bearing shot/bad.

It made a sound, heard at low speed. Sounds at higher speeds, where masked by tire, road and wind sounds.



These days with the age and condition, I find wheel bearings, wheel hub, FDS, ball joints and seals. I\Where I'll, very often recommend a knuckle restore service. I'm the only one, I know that offers it. This is where I remove wheel hub, steering knuckle and restore them both. At same time. I replace FDS, diff side seals, ball joints or ball joints boots if needed.

Points requiring restoring.

Wheel hub:

1. Hub flange studs. Mostly due to improper procedure. But thread do stretch and wear, with service. So some age related.
2. Hub flange. Mostly due to improper procedure. Also, I replace old, when installing new FDS.
3. Hub flange mounting seat. Always due to, improper procedure.
4. Wheel hub face (wheel mounting surface). Always due to, improper procedure.
5. Rotor. Age related and or improper procedure.
6. Wheel bearing & races. Age related and or improper procedure.

Knuckles:

1. Rust behind brake dust shield and wheel speed sensor port. All will rust. Some get very bad.
2. Curled ball joint boot seat(s). Always due to, improper procedure. From beating off ball joints. Proper is using a puller.
3. Busted bolts. Rust or cross threading.
4. Needle bearing & bushing. Mostly improper service, of not lubing. But they are wear items, that need replace on average 250K.
5. Seal in back of knuckle. Removed during restore, so must be replaced. Also a very good practice, to replace with FDS R&R.
6. Ball joints or just boots, if needed. With age, it is very good idea to reboot these days. OEM boots come with grease. packing grease into ball at joint, is key. Don't just smer on visible area of ball.

FDS: I don't restore. I remove & replace (R&R), if needed. key points to inspect:

1. Snap ring groove. Damage due to Improper procedure.
2. Splines of outer axle of FDS. Damage mostly, due to Improper procedure.
3. Remarkable play in CV,s. Age related. Also related to lift, without R&R of older well broke-in FDS.
4. Boots.
5. I replace Diff side tube seal, with all new FDS.

TRE:
If boot bad or play in ball, R&R with new OEM.

Any front brake pad or caliper work, as finnel touch.

 

[Super77]

Going back to the ‘Mud well for more wisdom. I’ve renamed the thread appropriately.

I think I have 2 unrelated issues:

1) loose DSF wheel (wiggles a little when pushed at 12 and 6 o’clock). That’s very likely a bad or badly tensioned bearing, and the posts so far are exactly what I needed.

2) what I described earlier as a “growl” is more of a rhythmic hum that seems to originate from the rear. It’s like the sound that new off-road tires make on pavement, except it’s rhythmic with speed, not constant. Incidentally, I do have new A/T tires.

My 62 had a similar noise develop and the shop advised it was likely the pinion bearing, but not urgent. That truck had 100K more miles than this one, though.

Thoughts on troubleshooting sequence?

 

[2001LC]

First time I heard my LC have rhythmic sound. Iit was a WA WA WA, rolling 60 MPH in N down hill. It's, when I learned we need to lube FWT & AFT propeller shafts, spiders (AKA drive shaft and U-joints) and slide yokes.

 

[Super77]

First time I heard my LC have rhythmic sound. Iit was a WA WA WA, rolling 60 MPH in N down hill. It's, when I learned we need to lube FWT & AFT propeller shafts, spiders (AKA drive shaft and U-joints) and slide yokes.

I recently lubed the u-joints and driveshaft splines (all grease points in the F & R shaft assemblies). Pumped in grease until it started to ooze from the spider ends and the driveshaft joints. I may add a little more to the driveshaft since I was super cautious not to “hydrolock” it with grease and cause damage.

 

[2001LC]

I recently lubed the u-joints and driveshaft splines (all grease points in the F & R shaft assemblies). Pumped in grease until it started to ooze from the spider ends and the driveshaft joints. I may add a little more to the driveshaft since I was super cautious not to “hydrolock” it with grease and cause damage.

Spiders will make that bad bearing sound WA WA WA. Slide yoke do not.

BTW:
Toyota changed recommendation on slide yoke lubing. To: Stop adding grease as soon as slide yoke moves. Do not try to get grease to pass seals. Although I've found in older under lubed slide yokes. Grease easily pass worn out seals. In these, we do need to lube more often. To stop the "clunk thunk"