Tire like noise - but not the tires!

[gtc]

Hi there,

'06 SEV8 here with some unusual noise, and hoping for a few thoughts before dragging the beast in to the stealership! Started hearing some flap from the tires a few thousand miles ago (!), and figured it was just the winters wearing out - we'd been running Pirelli Scorpions winter tires through the summers for the last ~30k miles as I had read that many were successful this way - and they were so much quieter then the GYs! I checked for cupping when the noise started and noticed it some pretty significant cupping, so ignored the issue knowing that some new ATs were coming in the spring and I'd get an alignment after install. Had some Yoko Geolanders put on two days ago (installer said the Pirellis still had 8/32 in the good spots!) and the noise didn't much change! My wife seems to think it's a bit quieter, but I know think I here a bit of a "grind" in the noise (switching the tires removed a bit of the treble from the noise, which may have been masking the grind). Here's a list of symptoms:

1) regular low frequency noise - (similar to tire slapping, or running over rumble strips)
2) noise matches tire rotation and is probably worst around 50mph
3) noise louder when turning left, very slightly quieter turning right
4) almost disappears around 75mph (could be masked by wind/road noise)
5) brand new tires, but no alignment yet (previous were well cupped)
6) occurs both in 4hi/4lo - no change in frequency of hum - matches tire rotation speed
7) no change /w DSC on/off
8) all brakes same temp after playing (ie, don't think it's EPB drum - which has bound in the past, but was pretty obvious)
9) acceleration strong & smooth from all speeds - hasn't changed at all.
10) brakes replaced 5k miles ago (DIY - may have screwed something up? was pretty easy other then the stupid rear sensor location!)

Any thoughts are greatly appreciated!

Just took it for a drive - additional notes:
1) No change if I switch to neutral while driving - same frequency
2) Locked up the brakes at 40mph, and also did some gradual braking - no shimmy/shake from the steering wheel (ie, I'm doubting rotors)
3) Tire installer (from 2 days ago) was surprised at how little balancing was required on the rims when the new tires where put on - 2 rims required no weights at all - the other two where .5 ounces.
4) haven't yet had bushings done - no "clunking", but am likely overdue at 68k miles...
5) really sounds to me like running over very closely spaced rumble strips!
Is it possible I'm far enough out of alignment to cause the tires to rumble?

 

[tlt]

Hi

It sounds similar situation to mine. The issue is your differential bearings I am guessing. The single biggest clue is;
3) noise louder when turning left, very slightly quieter turning right

The only other things to check are front wheel hubs, bearings. A reputable shop should be able to lift the wheels off the ground and put a stethoscope on it and confirm the noise at the bearings, etc.

Should this be confirmed to be the issue PM me, and I can get you a rebuild kit. The parts are not available from the dealer individually. The only thing you can buy are the diff seals.

 

[gtc]

Hi

It sounds similar situation to mine. The issue is your differential bearings I am guessing. The single biggest clue is;
3) noise louder when turning left, very slightly quieter turning right

The only other things to check are front wheel hubs, bearings. A reputable shop should be able to lift the wheels off the ground and put a stethoscope on it and confirm the noise at the bearings, etc.

Should this be confirmed to be the issue PM me, and I can get you a rebuild kit. The parts are not available from the dealer individually. The only thing you can buy are the diff seals.

Hi tlt - I looked at Houm's thread that you posted to just now; I'm not seeing any similarities in his descriptions to mine, though I'm certainly not ruling out the diff(s)! The sound is what I find so different - it's a repetitive thrumming (when I refer to "frequency", I'm not referring to pitch, merely the speed at which the thrumming occurs matching the revolutions of the tires). Again, like running over rumble strips on the road that are spaced just a few feet apart...

In any event, I'll likely be swinging by a mechanic in the next few days - if it does happen to be the diff, what's the price like on the rebuild kit?

 

[gtc]

UPDATE: turns out to be 2 different bearing issues (both fronts). One dried out, the other side loose. I suspect I'll let the stealership deal with it as parts are on back order, and they'll provide me with a free loaner until the parts become available. It's probably worthwhile to note that the SA indicated that a free loaner when parts are on back order is a LRNA sponsored plan for all vehicles regardless of warranty status if the vehicle is deemed hazardous to drive. While LR indicated that I could likely continue to drive on bad bearings, the SA was comfortable putting through the loaner request... granted, I am paying stealership prices, but they didn't seem to far out of line with a couple of posts I had seen here about indies!

I wanted to put a quick shout out to tlt - he went out of his way to PM with a nicely detailed note about the diffs and rebuild kits - should I have need for them.

 

[Dave Legacy]

Sucks about the bearings! May I ask what you've roughly been quoted for repairs?

 

[e24kgold]

Sucks about the bearings! May I ask what you've roughly been quoted for repairs?

+100

 

[gtc]

Pricing:

NB - I'm in Canada, so we get lousy rates on everything - should be cheaper in the US.

Parts:
Bearings - $285 x2
Tie rod end - $39 x1 (might as well, since I knew about it, and it was cheap)

Scheduled labor on the bearings is 1.5 hours per, they didn't mention a charge for the tie rod end, but likely there's a minimal amount of labor involved.

Also having a 4 wheel alignment done, which I was planning on anyway, as I just installed new tires - $149.

The killer at the local stealership is labor which I believe is now up to $145 / hour. I suspect I'll be in for 3-4 hours labor.