Fellow LR2 devotees, I have one that's got me stumped and would be most grateful for your help. Our little LR2 has 252K on the clock now, and over the last few weeks it's developed an intermittent growl. At first it was barely perceptible, but over a few hundred miles has gotten loud enough for everyone in the vehicle to hear it a little bit. At first it sounded like driving over patches of rougher pavement, but now it's like driving over subtle rumble strips every so often for 1-5 seconds in duration. It's most noticeable at around 55 mph, but it's audible at slower and faster speeds as well. The frequency of the sound feels like driveshaft rotation speed when it happens, and it's sometimes accompanied by a slight deceleration - almost like a when a shopping cart wheel shimmies.

It's not the rear diff pinion bearing - I know what that sounds like and rebuilt mine on the bench about 30K ago. I also replaced the Haldex filter and fluid while I was in there. The frequency of this new sound is somewhat lower than the usual rear diff whine as well. It's also intermittent and doesn't vary whether coasting or accelerating, whereas the rear diff while was constant. There seems to be a slight bit of play in the PTU output shaft bearing but I can't tell if it's coming from the pinion bearing or the splines until I get it up on jack stands this week. The front CV half shafts both have a very slight bit of up and down play, and they're both original. No evidence of grease seepage anywhere though.

I have a set of 4 chassis ears so I placed them at various places on the underside today and took several drives. Both front wheel hubs are quiet, and the left rear hub is also quiet, but the right rear is getting a bit loud. That said, it's still tight when I raise that wheel and give it a shake, and it turns freely and quietly in the air. Also, the sound from the chassis ear attached to it didn't match the growl. Both driveshaft support bearings are quiet. Both front and rear diffs are loud in the chassis ears, but that's not uncommon and the sounds didn't match the growl. Also, no leaks anywhere. So, I'm stumped. Anyone ever experience anything like this?

Next steps:
1/ Pull all four wheels and check for evidence of a stuck caliper, and will also get a better feel for each wheel bearing
2/ Check the driveshaft flange bolts for torque
3/ Check all 4 half shafts for noise and play
4/ Change the PTU fluid

Anything else you can think of?

 

Off the wall, but did you lose a balancing weight on one of the tires?

 

Throwing spaghetti at the wall, but here goes:
- Check tires for uneven wear patterns.
- Any difference in sound when driving straight vs turning?
- Any difference in sound while driving and then shifting to neutral?
- Do you have a sleeping pet snoring in the rear cargo area?

 

That's lotsa pasta!

 

Change oil in rear diff and look for metal shavings?

 

Thanks for your thoughts, but no nothing like that. Definitely not a wheel shake.

 

Thanks for the ideas! All tires are Michelin LTX and are wearing evenly.

No difference between straight and turning that I can tell.

Shifting to neutral is a great thought. I’ll try that next.

On the pet in the cargo area, you might be on to something!

 

Another good thought - thank you. I have a magnetic fill plug in it which would be an easy check as well.

I ordered a right rear wheel bearing and hub assembly, and will start the parts cannon there. It's getting noisy so it's only a matter of time anyway. And it might just be the problem. The thing about chassis ears is that they're good with medium and higher frequency sounds, but not so much on the really low frequency sounds. But all 3 of the other wheel bearings were silent and the right rear was pretty loud in the middle frequencies. I'll report back what I find.

 

Nice pooch!

 

Yeah I'd do the wheel bearing for sure, those can behave quite differently when jacked up with the load off vs. loaded at speed.

Next take a close look at the various drive shafts, did one get damaged or even dented? That could throw it out of balance. I can't recall if there are any rubber dampers installed on the LR2 shafts, but if those come off it can make low-freq vibration.