300D Belt Damper

[penderb]

Hello

Car is 1986 W124 300D Auto with 340,000 miles.
Can anyone give me or tell me where to find a detailed guide on how to remove the belt damper. Cannot find one on this site. But from reading up on the bits I did find, I discovered & tracked down a really loud tickover noise to be the damper, specifically a lot of free play on the bottom connection. As instructed by another post, I got a stick & pushed it against this damper while engine ticking over, low & behold,I could see damper moving in on the bottom & noise totally disappearing. So now I know the problem is a worn damper bottom connection, how do I remove same? Can I remove damper without removing anything else??
If I can turn bottom nut, and I believe from this forum, this nut is very very tight,can anyone tell me is this a threaded bolt going from front to back? is there some type of nut on the back?? Does this back nut come off if bolt removed or permanently stay there & just the bolt screws out??
Alternatively, I'm now thinking is there anyway of possibly shimming up the gap with some sort of U shaped type circlip?? and now for some off the wall thinking, how about liquid rubber, silicone??? mad I know.

Any info greatly appreciated.

Billy

p.s. tickover really sweet when stick firmly pressed against damper!

 

[Bolide]

Serpentine belt damper

There's no point in bodging the repair of this. Parts are too cheap to justify it and the bodge will fail, requiring you to do the work twice

Use Mercedes parts - order with your chassis/VIN number and the parts will fit. Every individual nut & bolt is available from Mercedes so replace anything that's worn

You may need to remove the radiator fan cowling to do this job. Early W124s had a one-piece cowling that is a swine to remove. You have to unclip the cowling, spin it through 90 degrees then feed it upward through the fan blades rotating them as you go

The damper bolts in top & bottom and, as I recall, the bottom mount is into a Y-shaped yoke on the end of the damper pivot arm. The bolt has a plain shank and tightens into the tapped portion of the back of the yoke

Above the belt tensioner spring there's a black plastic mount. Remove the bolt that passes through the mount and through the ally casting, the tensioner will swivel round & the belt tension will disappear. Remove the belt. Note the path. If you forget it there's a diagram in the user manual. Replace the belt and don't reuse it unless it's very new

Unbolt the damper & remove, noting the orientation. Check the damper arm, damper spring, idlers, alternator and steering pump pulleys for eccentricity and worn bearings. Check the water pump for leaks and make sure there's no movement in the bearings. Make sure the tensioner spring is still springy. Replace any suspect parts

Install the new damper. Fit the new belt. Put the locating bolt back in for the black plastic tensioner mount. It won't go through because the holes aren't aligned properly but have it ready. In the black plastic mount there's a vertical hole about 9 mm diameter. Put a long bar into this hole and use it to lever the mount back into alignment with the locating bolt. Push bolt through & replace nut

Check everything. Fire up engine & check belt path, tension & damper movement. Replace fan shroud. Check engine bay for loose tools. Drive away


Nick Froome
www.w124.co.uk

 

[penderb]

Hi Nick

Wow. Excellent detail there. My main concerns we're how tight the damper bolts are. I tried the lower one with nothing else removed, with a C spanner and thought, ouch, that's very tight, don't force it!! You did not make any reference to torqueing, so I assume, not necessary. I will buy the Mercedes parts/bolts. As luck would have it, I actually have a full spare Merc of same vintage and colour albeit the manual, it's damper has some play in it too, so will go route of new one, false economy to fit poor second hand one , plus I'm saving monies by fitting myself, it's not driving any more as I've "robbed" an odd part here & there for the auto model. Manual Merc was to become donor car for spares anyway. But now I'm armed with this info, will use non driving merc as a test to see if I can successfully remove damper as per your instructions. As you suggested checking some of the peripherals when belt off, have been thinking of getting alternator checked or probably replaced by alternator from manual Merc as I bought it fully reconditioned about 2 to 3 years ago, so ideally should do all together when belt off.

Many many thanks

Billy

 

[Bolide]

Bolts

Billy

Use a ring spanner or a socket - less chance of it coming off

IMHO diesel W124s are always worth repairing. What else could you replace one with? Might as well keep it going till 320 CDis are affordable - about 5 years, I reckon!


Nick Froome
www.w124.co.uk

 

[Parrot of Doom]

Be warned - it might not just be the damper. Mine went, 2 replacements later I had to take it to an indie who promptly replaced the shocker, arm, pulley, belt and various washers and things.

The shockers are quite cheap at £25 ish, but they fail quite easily (pee oil from the seal).

 

[penderb]

Nick

If i change, the next car I'm after will be the last of the 124's,, I want a 94/95 300D "multi-valve". From what I read on 320CDI's on this forum,, and I assume your talking the W210(Frog Eye Model), that cars from 2000 to 2004, have some potential problems, specifically paint finishing, etc, etc, I'm almost frightened off buying any W210, but heart says wow to a 320CDI full avanygarde spec,big alloys, but the head says, hhhmmmm, now wait just a minute. The heart would love that 320 cdi engine, auto tiptronic box, awesome power combined with diesel economy. But all that electronic technology in the 320 CDi, I'm wary of too. My job entails 108 miles round trip a day , 35 - 40, 000 miles a year, mostly motorway miles, so 320 CDi would eat that up!! 124 loves this journey too.
I remember when I got my autobox refurbished in Jan '05, I'm based in Ireland, so had a Dublin autobox specialist do the job, flyin still, but from conversations with him about costs to rebuild W210 boxes, ouch! And they we're in just as often if not more for overhaul. Autobox guy loved the 124 boxes. Incidentally nothing in my box was re usuable, everything had to be replaced. Dipped regularily, only dipped it again on Sat, lovely clear reddish colour & level still perfect. Gonna change it soon!

My 124 box cost €1200 Euros, he mentioned 210's could cost at least €2500 Euros

Thanks for tips Nick,

Also Mr. Parrot of Doom, thanks also for unput, all experiences are invaluable.

Billy

 

[Bolide]

W124 Multivalves

Billy

I swopped my 87 250TD for a 93 300 Diesel multivalve earlier in the year. It came to me with 198k and FMBSH. The car's not perfect, and will need a box rebuild in the next 2 years, but it drives as well as my 250TD did 10 years ago

The multivalve is "the one" as far as I'm concerned. I'm just hoping someone will phone me one day and say they've discovered a stash of 20 low-mileage examples they want to get rid of...


Nick Froome
www.w124.co.uk

 

[penderb]

Nick

Couldn't agree more on 300 multi valve, funny, no interest in the 250. I have this thing where the 6 cyclinder is the better balanced engine for some reason, think I read it somewhere. Even allowing for doing the box in your multi valve, it's not a huge fortune, as the driving pleasure combined with how long the car\engine will last(bullet proof in my opinion!). Even when I get around to buying a multi valve, am quiet happy in the knowledge that I'll have to do the box at some stage, Ive been through it with current car, have a box specialist I'm very happy with. Incidentally, read your website, I see where the last of the multi-valves had the 5 speed auto & are rare, mentioned this before on forum, to who I don't know,and they wouldn't believe me that a 5 speed box existed. I check the autotrader online regularily to see what multi valves are for sale. From what I see, some good value cars there. Is there anyway to improve performance, tuning etc, for multi valves, I know there lively enough, but because no turbo due to steering box position/location, would a K & N air filter help much?, just a thought, can't think of any other tuning mod, very limited I suppose.

Billy