Drivetrain Noise, possibly driveshaft? 2005 S60R

Post by **bmdubya1198** » 11 Nov 2020, 19:43

I'm trying to figure out this knocking/grinding noise on my friend's 2005 S60R, and initially I was pretty certain it was the angle gear, but the more I look into it the less I think that's the problem. You can clearly hear the noise in the video, so I won't go through describing it too much. It's a clunking/knocking noise.

Anyway, it's only noticeable at lower speeds. No difference whether the clutch is engaged or disengaged. When backing out of the driveway, I can hear it, then once I start driving, it starts making noise over about 5 mph. Then I can hear it clearly in 1st through 3rd gear while driving around the neighborhood between 20-30 mph. Coasting to a stop, I can hear it as well, so there's no difference with the drivetrain loaded or not.

When checking everything out underneath, I couldn't find anything obviously wrong. Axles are in place (not an axle ping issue) with no movement. The angle gear is wet, probably leaking from an axle seal. I pulled the fill plug and can feel that the fluid is full. It almost looks like it has a metallic sparkle, but I'm not totally sure. Spinning the wheels, I didn't hear anything too abnormal until I was able to spin them a little faster, when I could hear a little it of noise. It's hard to tell though since I can only spin the wheel so fast while listening under the car.

Moving around the driveshaft, it DOES make some noise, but its hard to tell if it's the source of the noise I'm hearing while driving. I don't know if it could be the center support bearing or maybe the u-joint just aft of that.

Anybody have any ideas?

Post by **darrylrobert** » 12 Nov 2020, 04:20

if you put in in 5th gear the wheels will spin much faster, i would remove the drive shaft you may even find the bolts are loose.

Post by **RickHaleParker** » 12 Nov 2020, 04:53

Use a Ear Trumpet to isolate where the sound is coming from. A clean Transmission funnel or a large hose can be used as a Trumpet. The idea is to make your hearing directional instead of the natural omnidirectional. Cupping your ears might do the trick.

This is where a Mechanics Stethoscope with a Trumpet attachment comes in handy.
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Post by **bmdubya1198** » 12 Nov 2020, 07:42

Good call on the transmission funnel, I’m going to give that a try. I’ll try putting it in a higher gear as well.

Post by **jonesg** » 12 Nov 2020, 09:28

I say prop shaft center bearing support.

Post by **abscate** » 12 Nov 2020, 12:26

CBS is my horse too...

A piece of hose pipe will work to isolate , too

Post by **bmdubya1198** » 12 Nov 2020, 20:12

Yup, managed to listen under it with a pipe earlier and it turns out it's the angle gear. I'm surprised, it really sounded like the CSB as far as the location! I ended up pulling the driveshaft as well, and while the CV joints are really dry and rough, they don't seem to be the source of the noise. That's just a separate issue.
I'll update this thread with my findings. While the collar is the common failure, based on the fact that the rear wheels are turning normally and the sound, it could be the angle gear itself.

Post by **Blacklab467** » 12 Nov 2020, 20:51

It sounds like something inside the Bevel Gear like a bearing that came apart. I don't think it's the Collar as they usually make a buzzing noise as they spin over worn splines. Regardless you'll find out soon enough. I was able to drive mine in FWD with the BG removed and the collar in place while I sourced out parts to repair. I'm not sure if you can do that with the M56?

Post by **bmdubya1198** » 13 Nov 2020, 09:02

Blacklab467 wrote: 12 Nov 2020, 20:51 It sounds like something inside the Bevel Gear like a bearing that came apart. I don't think it's the Collar as they usually make a buzzing noise as they spin over worn splines. Regardless you'll find out soon enough. I was able to drive mine in FWD with the BG removed and the collar in place while I sourced out parts to repair. I'm not sure if you can do that with the M56?

Oh, this is an M66 S60R, not my V70R. I think you may be right though, I'm not sure that it's the collar. It still transmits power to the rear wheels just fine, no excessive slop in the driveshaft or anything either. I'm going to pull the angle gear today and see what's up.

Post by **Blacklab467** » 13 Nov 2020, 10:31

I wonder if it might be the CV shaft support bearing? You might get lucky on this one. If the flange isn't sloppy and there's no leakage on the Bevel Gear it might be ok.