Mystery Noise - Right Rear

[bpossel]

UPDATE...
  Finished replacing the right axle bearing (with correct spherical roller bearing).  It was a tough job, but with Joe's excellent instructions and the help from many folks on this site, got it done!
I would say that the key is to ensure you do buy the kit, which includes all of the correct seals, lock nut, plate, etc).  Also, borrow a slide hammer from Autozone.  It helps, but only use it until the bearing is out.  Then tug buy hand as per instructions.  It was hard to get the spherical bearing to go in straight, but it did with some patience and some prayers...

  The only sad part is that with all the work....  my intermittant noise is still there...  So was'nt the bearing after all.  But I know that I would have had to do this job sooner or later.  When I loosened the brake backing plate, prior to pulling the axle (bearing) out, a small amount of differential fluid came out.  I shouldnt have seen any trace of differential fluid until I pulled out the bearing and back seal.  So had a leaky back seal....

If this was a couple of years ago, I'd be crying right now.  But, hey, these cars are fun to drive and fun to work on...  I just enjoy being outside...

Now what?  Maybe its the left side bearing echoing through the axle tube over to the right side?  Maybe its lack of hearing in my left ear?  I am now pulling at straws...

====================================================================
Hi All,

I have been struggling with a noise coming from my right rear wheel area…  it started last Fall after I put my 113 through a grueling defensive driving course, sponsored by my local Memphis MBCA group (great event and lots of fun!)

The noise is rotational in nature, in that you can hear it as I back up and go forwards (as the wheels move).  The noise is not heard for the entire wheel rotation, rather only heard for about 1/3 of each full rotation.  The odd thing is that the noise is not present all of the time.  It is most noticable when letting off the accelerator and coasting down an incline (30-40 mph).

[!]The noise sounds like a metal to metal scraping noise.  Last week had a local MB mechanic check the car over (not an experienced 113’r…).  He had the car on a lift and checked the drive shaft, wheel play for bearings, and all other stuff under the car.  I was with him in the shop, under the car, and know he did a thorough check.  In the end, he couldn’t find anything wrong, although he did hear the noise…  Note: no noise is heard while car on the lift and spinning the wheels.  Noise only present under load conditions).  His only suggestion was to replace the lower axle hanger mount (as per my previous posting on this) and this was a suggestion only because we saw a bit of loose rubber at each open end of the carrier pin mounting bracket.  Rubber inside the carrier pin is most likely ok…

Here is what I have done so far to the car since the noise developed and the noise is still there:
1. swapped wheels (front to rear)
2. replaced rotors (all 4)
3. replaced brake pads (all wheels)
4. new rubber brake hoses
5. replaced all 4 brake calipers
6. replaced brake master cylinder and brake reservoir
7. power bleed brake system several times
8. MB dealer alignment
9. replaced upper rubber axle carrier mount in trunk
10. new rubber rings for muffler
11. tightened muffler heat shield
12. changed diff fluid (85w 90)
13. replaced right park brake cable
14. replaced parking brake pads, springs)
15. Ensured brake dust cover not touching anywhere

While waiting for the parking brake pads and cable to arrive, I re-installed the brake rotor and did a test drive to see if the noise was related to the park brake, no luck, same scrapping noise.

Also when I had the brake rotor out several times, I checked and looked for any shinny spots to see if it was rubbing anywhere.  No luck, no shinny spots.

Drove the car down several streets swerving side to side to test for possible bearing issue.  Neighbors think I’m a drunk (I will be soon if I cant solve this one…).  While swerving and turning, the noise is no different.  The metal to metal scrapping noise is there turning the wheels or going straight.

 :?: Can anyone think of what this noise could be?  Any other ideas for testing?  If I only had a local MB mechanic that really knew these 113’s I would take it there…

Sorry for the long post!
  Help appreciated!
Bob

bpossel
Memphis, TN.
1971 280SL
1997 E320

[Vince Canepa]

Bob - I had a similar noise.  It started as a scraping noise when turning, later it developed into a rumble. The scraping sounded like sheet metal scraping.  It was the wheel bearing.  When I took everything apart there was no damage other than the bad bearing.  From listening to it I thought I would find scrape marks somewhere.

Also, a few months back one of the boarders had an issue with the parking brake that caused some noises.

Vince Canepa
1967 250SL
113.043-10-001543
568H Signal Red
116 Caviar MB-Tex

[jeffc280sl]

Hi Bob,

Vince has already given you my first idea.  You may also want to check the drive shaft u joints.  When the needle bearings get dry and worn they can sometimes make strange noises.

Jeff C.
1970 280SL 4-speed

[rwmastel]

quote:Originally posted by bpossel

If I only had a local MB mechanic that really knew these 113’s I would take it there…

Bob,
It sounds like you are that mechanic!  I'll be other Pagoda owners will start knocking on your door not too long from now.  You've done more to your car in 1 year than most of us have done in 5.  Keep up the good work, you'll find the cause of this noise.

Rodd
Powell, Ohio, USA
1966 230SL, Euro, Auto, Leather, both  tops
1994 E420

[bpossel]

Thanks Vince, Jeff, Rodd (& Joe),

What is baffling are the symptoms...  I suspected the bearing, but with the metal to metal scraping noise... not what is typical with a bearing going bad...  

With what Vince described...  started with similar scraping noise then went to the typical groaning noise...  I will now focus on the bearings...

Vince, others...  did you pull your own right axle and replace the bearings?  Did you pull the left axle out to get the right axle out?  What parts should I order besides the bearings?

Maybe I should go ahead and drop the entire rear axle and do it all?  I wish I had the alignment tool to reinstall the rubber donuts on front of the rear swing arms.  I always have trouble aligning these up again and reinstalling the nut.  Does anyone know where I can find one of these alignment tools?  Looks like a metal cone shaped thingie in the BBB... that screws on the large bolt that holds the front of the arm and rubber.

Thanks again! ...  off the church.  Wife wont let me skip today...
Bob

bpossel
Memphis, TN.
1971 280SL
1997 E320

[JimVillers]

Bob ... Axle bearings are not hard to replace and do not requiring pulling the rear end.  My 230SL has drum brakes so may be a little different.  Pull the brakes off, unbolt the four retainer bolts and pull the axle out with a slide hammer (the slide hammer is easy, everything else is hard).  The hard part is removing the bearing retainer (I used a 36 inch pipe wrench) and removing the bearing.  Joe A bounced the axle on an aluminum block to remove the bearing; I used a large press at a local shop.  If everything works, it should take about two hours; if not, a lot longer.

Jim Villers
190SL, 230SL 5-Speed, 190E 2.3-16 Kompressor

[Benz Dr.]

I got lucky enough to find an original wrench used to remove the axel nut. Sure makes this job easy.

 I use a shop press to push the bearing off. Anything else can damage the end of the shaft. NEVER hit on the splined end or it won't fit back into the diff. probably due to being peened.

Dan Caron's
 SL Barn
benzbarn@ebtech.net
 slbarn.mbz.org
  1 877 661 6061

[bpossel]

Thanks Dan, Jim for your responses.

To remove the right axle, do I need to remove the left one first?

Also, to remove the axle, doesnt it have to be at some sort of angle, hanging down?

Isnt there a "trick" to removing the right axle, then reinstalling it?

Also, what parts do I need?  New bearings?  Seals?

Thanks again for your help and advice...

Bob

bpossel
Memphis, TN.
1971 280SL
1997 E320

[Vince Canepa]

1) You do not need to pull the left or right side to do the other.  They can be treated independently.
2) The angle is not a factor pulling the axle.  Your right axle should have a circlip on the  inboard end, at the sliding joint.  The "trick" is to start pulling the axle until you feel the clip resist, then turn the axle through a rotation to center the circlip, then jerk firmly straight out.
3) Going back in the right and left axle tubes must be at an included angle of 22 degrees.  According to the BBB the rubber bump stops must be removed to get this angle.

Do you have a BBB or one of the CD's?  The procedure is described in Section 35.



Vince Canepa
1967 250SL
113.043-10-001543
568H Signal Red
116 Caviar MB-Tex

[bpossel]

Hi Vince,

Thanks!!!
Bob

bpossel
Memphis, TN.
1971 280SL
1997 E320

[Ben]

I may be totally out here but suspecting all of the things you have looked at, I found that the rubbing/squeaking/vibration on my car was caused by one of the wheel weights on the alloy wheel rubbing off the inner wheel arch !

I had some shot bushings and an issue with axle centralisation too but you should just take a quick look at the inside of your wheels and the area inside the wheel well !

It could be that simple !

Regards,
Ben in Ireland.
'64 230SL 4sp.

[bpossel]

Just doing some more reading and planning ahead while waiting for all the bearing parts to arrive....

Question...  when reinstalling the axles (after replacing the bearings) the BBB states that the axle tube needs to be at 22 degrees.

Besides removing the rubber stop, does the rear spring have to be removed to get the axle tube to move up to a 22 degree range?

Thanks!
Bob

bpossel
Memphis, TN.
1971 280SL
1997 E320

[Vince Canepa]

Yes, the rear springs must be removed.  The springs will be at their rated load and start supporting the car as the axle tubes are approximately level.  I'm not sure about the compensating spring.

Vince Canepa
1967 250SL
113.043-10-001543
568H Signal Red
116 Caviar MB-Tex