Propeller (Drive) Shaft Alignment of two pieces

[Jim]

I searched and found some propeller shaft balancing text here

http://500eboard.com/forums/showthread.php?667-For-Gerry-s-database

but I'm starting a new thread as this seems to be an issue every so often.

Question - How to put a two piece propellor shaft back together if you did not mark it before taking it off?

I attach 3 pictures of what I think could be the relevant marks.

So does my single dash point at the cast "B"?

or

does my single dash point between the two dashes.

Look at the pictures and you will see what I mean.

The B and the two dashes are 180 degrees apart.

Thanks.

Jim.

 

[gsxr]

The single dash goes between the pair of dashes. Ignore the "B" mark.

See page 26, step 13 of the FSM procedure:

http://www.w124-zone.com/downloads/MB%2 ... df#page=26

 

[Jim]

Thank-you Dave. Odd that Google did not find that resource...I probably should have used a variety of different search criteria.

Now I can check what was done on my car and re-furbish the old one sometime.



Jim.

 

[Jim]

I'm still tracking down the vibration I inherited from the diff, gearbox and prop. shaft change I had done.

I changed the gearbox mounting yesterday. It was easy even without a trolley jack. I just needed a prop the correct size for the gearbox and lowered the car using the OEM side jack. Of course the wheels etc. were all jacked up to allow safe working.

I am glad i did the job myself as the two bolts in the bottom were in poor condition. As the dealer was closed for the Public Holiday I replaced them with local hardware store 8.8 marked bolts.

The picture shows the old (on the right) and the new mounting. Part Number A 140 240 08 18.

The old one had sunk about a centimeter.

Test drive made the vibration feel different but still very much there.

Jim.

PS...I lowered the exhaust and took the heat shield off so I could see the propshaft joint. The Abu Dhabi mechanic of 15 years and/or his assistants had lined up the two pieces about 180 degrees wrong.

PPS...I put the car into the local dealer to remove and correctly re-fit the propellor shaft. The 60 to 75 km/hr vibration has gone. There still seems to be some wheel vibration, probably from the older rears I'm trying to get some wear out of...the steering wheel shakes a little...odd since the fronts are both new and balanced on a Hunter Machine with me watching.

 

[Jim]

Re: Propeller (Drive) Shaft Vibration

When I was on leave I left my car with the MB dealer; the Technical Manager was going to see if he could resolve the vibration around 60km/hour.

They actually seem to make the vibration worse. They fixed the alignment to 98% perfect, cured a leak on the steering box and adjusted the parking brake.

So when I returned and the jet lag had worn off I worked out that the engine mounts being weak/low, combined with the new gearbox mount I fitted, would have the effect of pushing the centre propellor shaft bearing up.

So today I had a local independent garage fit two new Boge engine mounts.

Driving home in the midday sun the vibration is less to the point you can mistake it for road vibration unless you are looking for it. There is still something else.

I can confirm what others have said; that is the fitting of new engine mounts has a huge impact on the smoothness of the car. I'm very pleased with that outcome. There was about 4mm height difference between the old and the new when compared unloaded. One old one had the oil leaking out. Before changing I could get a hand of fingers between the sump and the cross-member, so thats about an inch. Not sure what the clearance would be now.

What I would like to do is drop the propellor shaft and try to put a laser between the two spiders to check the concentricity alignment. Another check would be to put straight edges radially out from each spider to check if they are parallel. Being 4 leg spiders that would be easy.

 

[195910]

As I remember, this is a major accident damaged car. Try to check if the whole frame is aligned as well. The body can be twisted.

I had a vibration Issue once that turned out to be the Dunlop SP Maxx tyres. The ones we get are made in Japan (In Europe they are made in Germany).
Quality is so poor that I threw them away after a year. Traction was like driving on Ice.

 

[Jim]

The car drives beautifully straight following the MB dealer wheel alignment. It is a joy, with no pulling at all and sweet up to 175 km/hr. In fact the faster you go the sweeter it becomes. I love the 2.65 diff.

On the weekend before last I had the independent garage put my old, presumably original propeller shaft back in. The old one had a sticky UJ in one plane. This was cured by soaking for a few days in a mixture of diesel and paraffin.

I was on hand to help remove the "new" one fitted in Abu Dhabi and later re aligned by the MB dealer here in Muscat. They (MB) did the work while I was on leave. I explained to the "Best" Reception man about the alignment marks have to look like this -=

Yes you guessed it...the shaft came out 180 degrees wrongly aligned. The dealer had changed it...but despite my efforts they made it worse. It went in 120 degrees wrong...found by me underneath...and they made it 180 degrees wrong.

Anyway the Indy put the old one back in and I personally saw the alingnment marks were OK. After a week or so the vibration is as bad as ever and still at 65 km/hr to 75 km/hr.

This evening I saw on Peachparts someone swearing that the cause would be wheels. So out I go and take off the rear OEM Std wheels and fit my now matching 19 x 9.5's. Still no improvement.

It was between 40 and 45 degrees when we pulled the shaft and I forgot to check the Gearbox and Diff spider tightness...do you think this would be the next thing to check?

The flexible joints are new. The gearbox mount is new, the diff mounts are new. The sub frame bushes I think are poor. The diff whines a little.

The odd thing is that the vibration is the same with both propeller shafts. The center bearings are smooth with good mounting.

The new shaft fitted in Abu Dhabi also has a sticky UJ...so it should not have been fitted like that.

The MB Technical Manager told me the transmission alignment is with in limits. They have some special fittings that allow it to be checked. Given the rubbish work so far...do I believe the German?

It's odd that there was no vibration when I got the car originally.

I am expecting a call from the MB General Manager tomorrow to make an appointment to tell Him my tale to see if I can get some money back. Should be good for a laugh...

Constructive suggestions appreciated...

Jim

 

[195910]

have it checked by an independent shop that works a lot with the 80s 90s MB.. Dealerships in the Gulf use cheap labour, its only a month worth of training that separates them from garbage collectors! While you can find Indy's with 30 Years of fixing MB's.

I am not sure about the UAE, But it can probably be sorted Q8.

 

[500AMM]

Hi Jim.

Interesting reading and a great write up of the development. Since you are referring to a specific speed for the vibrations, not a specific RPM, I guess it is either from the driveline, suspension or brakes. I assume you have checked for any balance issues in the brake discs?

-arnt-

 

[Jim]

Arnt...The discs have not been checked but they are the same as before the Gearbox, Differential and Propeller Shaft swop and there was no vibration then. I do not think there has been any aggressive driving to warp the discs and in fact the brakes are just great at the moment...apart from being completely standard of course. To be honest I think the vibration is coming from the nose of the diff. I am still background working on some vibration monitoring equipment, should be possible and not too expensive. This vibration seems really common based on my Web reading about 1 in 10 threads end with a good cure.

The MB Dealer did make an incremental improvement. Also for some reason the vibration is less following the car just sitting while I was in UK on 5 weeks leave. When I picked up the car from the dealer I was livid to find a "push to close" dent in the bonnet. OK there were a lot of mechanical issues on the car, the major ones now having been sorted out; but the good news on the car was the engine conition and the face lifted paint job. I was really upset to find some ******** could not even close the bonnet with out doing damage.

I still have some small clonks at the back, perhaps only one but it is hard to track down I feel as if there is some rear wheel steering when applying power with right lock applied. I looked at the subframe mounts and they look ok but can you really tell?

Anyway as a daily driver through the heat it's a good car with power to keep up and get one out of trouble and the AC works well. Every few weeks I find a note under the wiper asking me to sell the car and people turn to admire it. The OEM wheels are DIY refurbished and I keep them clean which helps.

Thanks for the interest Arnt.

Jim.

 

[DerFuror]

Hi Jim.
Interesting reading and a great write up of the development. Since you are referring to a specific speed for the vibrations, not a specific RPM, I guess it is either from the driveline, suspension or brakes. I assume you have checked for any balance issues in the brake discs?
-arnt-

Warped brake discs will noticeably vibrate (shudder/pulsate) while braking & be mostly imperceptible during non-braking condition...but how about putting a set of different rear wheels/tires on & going for a test drive thru the problem speed range?

Otherwise, if in fact your driveshaft is in properly refurbished condition (correct fit, alignment, balance, good u-joints & flex-discs), mounts are new, I would surmise that the critical fasteners are not torqued correctly to spec...Also make sure the flex disc fasteners are uniform (all the same & not mismatched bolts/nuts).

Since you mention your car was driving fine earlier, I don't think your previous accident damage has any impact on the vibration issue unless the repairs are now failing.

 

[Jim]

I put the AMG 19's on to eliminate the wheels; also the wheels have been balanced, including road forces...in some cases more that once.

 

[fudgitive]

I am not sure about the UAE, But it can probably be sorted Q8.

There are a couple of independent shops in the Rashidiya area in Dubai that employ mechanics with 20+ years experience and work on older Benzes, but you have to ensure that only these guys work on your car, which is the difficult part as they tend to mainly diagnose then let the lesser experienced people do most of the work and move onto the next vehicle. I also have a worsening vibration problem at the moment but am 99.9% sure it is only engine mounts.

 

[Jim]

Fudge,

That is similar to what happened at the MB Dealership...I found the Propeller shaft 120 degrees incorrectly aligned from Abu Dhabi, I told the Best Service Reception Man at the MB Dealership here in Oman what was wrong and they still carefully put the shaft 180 degrees wrong. I found that at an Independent workshop (45 degrees and no AC). I went back to the MB Dealer GM and complained; so the next time the MB Technical Manager put it on their alignment jig (that can do propeller shaft alignment with the correct fixtures and fittings), putting me where I am today as reported earlier.

Jim.

 

[fudgitive]

Jim, hope it gets sorted out soon anyway. The best mechanics can indeed be found in the most unlikely places, personally I find that a basket of sweets and a bottle of Johnny Walker discreetly distributed to the appropriate people on the shop floor achieves much better results than a shouting match with the service manager ever will in these parts. Must do a weekend drive to Muscat one of these days too !

Mike

 

[Cavanman]

I had a similar sounding problem with a vibration in my car. In my case it was at about 100 kph and felt like an unbalanced wheel. To cut a long story short (don't worry, there are more details below...) the vibration went away almost completely when I switched from Goodyear Eagle tyres to Michelin Pilot Sport II tyres.

To give a bit more background, the car when I bought it had Goodyear Eagles fitted. It also had the vibration; noticeable but not too bad. I had all the tyres balanced, moved front to rear and when I changed tyres (two at a time) the new tyres did not make any difference.

At one time I jacked up the rear of the car with both rear wheels off the ground, bypassed the ASR and spun the wheels up to 100 kph. I identified the problem wheel as the left rear wheel as the vibration could be felt and seen when the wheel was spinning. Remove the wheel and the vibration went away so it was not some other part of the drive train. The right rear wheel was completely steady.

I checked the wheel, the hub and the disk for runout using a dial guage and all were way inside the limits, tenths on a mm even at the wheel.

I had read of similar issues with SL500s on the web and reckoned I'd have to live with it. When I changed to the Michelin tyres all round, the vibration disappeared... I don't think the Michelins are as good a tyre as the Goodyear, but that's a different story....

My own feeling is that the vibration a natural frequency of some portion of the rear suspension and that even the slightest out of balance will excite it.

 

[gsxr]

Jim, did you ever get this sorted out? I'm curious what the root cause of the vibration was.

 

[Jim]

Thanks for asking Dave...

Casting my mind back the problems with this car started when I was replacing the tyres...the gearbox had a huge loss of drive following the tyre shop lifting the front right too high...at least that is what seemed to happen.

Zayed found a 722.370 replacement box and "while his shop was in there" he replaced the propeller shaft and some other items including a 2.65 differential... I think the details are earlier in the thread. Zayed's prop. shaft was re-painted and I suspected that was causing the imbalance.

It is coming back to me as I write...I found that prop. shaft was out of alignment, meaning the casting marks on or near the spiders were not correctly aligned,

I took the car to the MB dealer in Muscat and told them to refit the original prop shaft, even telling them how to do it. The vibration was still there so I went under with a mechanic and pulled the shaft (45 deg, C that day and no air conditioning). The MB dealer had done it wrong and made a dent in the bonnet...grrr.

OK fast forward 3 years with the car in UK occasionally used. Earlier this year a friend in the Netherlands was driving the car prior to doing some work for me. The vibration was still there at about 75km/hr and he was convinced it was...wait for it...wheel balance...any way having picked up the car and driven it back to UK it does seem that the vibration has gone. Doh. Back in Oman I never had a chance to drive on the new tyres. I limped the car back from the tyre shop and it was flat bedded to Zayed's shop of choice in Abu Dhabi; It was not until I was driving back from Abu Dhabi that the vibration became apparent...and that was the first time I had driven on those new tyres...and I assumed it was the new drive line components.

So what have we learnt...

- Do not jack the car too high...not sure this was really the cause of the gearbox failure.
- Make sure the workshop (not the service reception) really do know how to fit a propeller shaft.
- Make sure the wheels are carefully balanced "using a road force machine."
- Do not leave any thing in the car when going to the workshop.
- Note the fuel level and the odometer reading
- Inspect carefully before and after for things not fitted correctly, e.g. body marks; engine and gearbox earthing strap.

 

[samiam44]

"The MB dealer had done it wrong and made a dent in the bonnet...grrr."

Wow they didn't support things when they removed the transmission mount to get at the fwd flex disc bolts. Tyres and also rim straightness. Vibration in the front wheel only can be wheel bearings. I always look and play with the spline alignement a bit. If you set the ujoint so it is on a board and look down (I use a straight edge) there will only be one right place.


Michael

 

[Jim]

The bonnet dent was Omani Trainees pushing in the wrong place to close the bonnet...