Drive shaft / Hub Bearing issue

[lithiumus]

I believe I have an issue with either my Drive Shaft or my hub bearings where I am getting a rather loud helicopter / grinding noise in the rear. I've had my car up on jacks and there is no side movement at all from the rear wheels (yes I released the parking brake) so I suspect it may be a drive shaft.

The noise is independant of transmission and directly related to the speed of the car.

Is there any danger in continuing to drive or taking a long trip? I'm planning a 10 hour drive and I'd like to take the NSX but will leave it in the garage if there is any potential of failure.

 

[ATERPAK]

Are your brake pads in good shape and not near their wear limit scrapers?

 

[titaniumdave]

I would look at the CV joints. With the car on jack stands, put the car in neutral and rotate one wheel, see how much play there is from where the wheel starts to rotate and you can feel the differential start to move. Compare the 2 sides and see if there is a significant difference. If there is, that might be the problem, one of the joints is worn.

Also check and see if there is a tear in one of the boots which cover the CV joint. Even a slight crack in the rubber can all the grease out of the joint and ruin the joint in no time. There will be a tell tale sign of a line of grease spun off the offending boot. If one boot is bad, replace both of them on the drive shaft while it is apart. It might help to have the car up on a lift, have the car running and in gear with someone at the back end, listening for the sound.

I have not seen the wheel bearings go bad, they are pretty tough, but I am replacing the half shaft bearing on my car right now. It only has about 60K miles on it, thought lots of track miles, all with a supercharger. It might be another place to look, hard to get at with out pulling the right drive shaft. I could not tell mine was going till I had the half shaft out...

After all the hard to do things, first make sure it is not something very simple, bad tire with a bulge, fender liner dropped down and hitting the tire, loose e-brake cable, etc. I once had a car that made the worst noise at hi way speeds, took me the longest time to figure out there was a slight bulge on the inside of one tire that would rub something under the fender when I hit just the right speed...

 

[lithiumus]

Thanks again Dave. Great suggestions and you are right, I'll definitely check the quick and easy things first!

I'm suspecting driveshafts. Any harm in continuing to drive this or better be safe than sorry? Planning a 10 hour drive (just highway). What do think? Park it?

 

[titaniumdave]

Park it, no question!

If you have a boot that is leaking, it can be a couple hundred $ fix now. If you seize a CV joint, costs are going to go up exponentially, plus you are looking at a tow:redface: Don't temp fate...

 

[lithiumus]

Good call. don't want to ruin a nice weekend trip! Thanks again. I'll post results as soon as I locate the root cause.

 

[lithiumus]

So I finally had a chance to get the car up on jacks to test...

I manually turned both wheels and the amount of play on both wheels were equal. The CV boots all look good and no leaking was found. I rechecked the rear wheels for camber play to see if the hubs had gotten any worse but the wheels are rock solid.

I ran the car and spun up the wheels to about 40mph and disengaged the tranny into neutral. My brother and I both listened for the grinding noise but there was none. I spun it up to about 60mph and again, compared to what it sounds like in the car on the highway, this was whisper quiet.

I think my driveshafts are fine. The noise only appears under load which points to possible wheel bearing issue but I can't be certain.

To eliminate the wheels, I'm going to pop on my OEM set of wheels and see if the noise goes away...

I noticed that all of my wheels have a very slight brake grab when they were in the air. I would turn the wheel and there was a very slight scraping noise from the brakes. I hear this on each corner. I can't imagine that's normal...

 

[Synthesis]

i posted on here before about a similar noise my car was making, but i never got an answer.

my car was making an intermittent droning noise, similar to the sound you hear sitting in an airplane. same thing - mine would increase in speed with increased vehicle speed. also, when i would turn right, it would increase speed even more, and when i'd turn left it would lessen.

it ended up being the rear hub bearings. after i got those replaced, no noise :smile: