Greetings everyone!

I've utilized the helpful threads on this message board more than once when fixing my 300D since purchasing it earlier this year.

I did a couple quick searches for my current issue but I wanted to go ahead and post my own thread with some specifics (if there is a thread detailing exactly what I'm asking that I may have missed, please feel free to point me to it).

Today I was driving home on the highway and everything was running smooth and fine with my car. Suddenly I couldn't steer, noticed my battery light was on, and saw the engine temperature spike sharply (and max out shortly after).

I made it to a gas station and saw a belt hanging down below the car. I thought maybe I just needed to replace the belt and be on my way, until I saw a pulley wheel completely severed from the engine.

Needless to say, I had the car towed, and now I'm at home trying to determine if I can get everything replaced and working on my own.

I've attached a couple pictures showing the severed wheel, as well as what remains attached. You can see in the second picture that a couple bolts actually came loose in the tear (or perhaps caused it).

My hope is that I can just purchase a new pulley wheel, attach it, and be good to go after replacing belts. I'm concerned one (or more) of the bolts may be bent or that the threads where they attach may be stripped or otherwise ruined. I guess I won't know til I take them off, but I'm just looking for a little pre-emptive advice should that be the case.

Assuming everything is okay and I can get a new wheel attached, what kind of workload am I looking at for getting the bets replaced and working properly? Any advice on any of this entire process will be very much appreciated.

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Welcome to the forum mig50.

Impressive pictures there. That's rusted right through.

I had to drill out those bolts on the crankshaft pulley on my OM617 with the pulley in place. You've got a slight advantage there that the pulley isn't there any more.

To be able to reach on in there I removed the radiator so I could sit down in front of the car and drill away.

I guess the best place to get a replacement pulley would be a scrap yard or to post a WTB (want to buy) ad here on the forum.

Oh and you won't know about the threads until the bolts are out...

__________________
1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

Unusual failure I think. Should be able to bolt on a new pulley.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

Just got what was left of the pulley off the engine. A couple things to note:

1. One of the bolt heads was at an angle and felt kind of loose. I feared something behind the pulley had broken / bent / de-threaded and that I would be in for quite an ordeal. Turns out the bolt itself was bent but the internal threading (and most of the bolt) is still straight and fine. Phew!

2. There is a missing bolt. How this didn't fail sooner is beyond me.

I know of at least one Mercedes place in this town, so I'm going to call tomorrow to see if maybe they have a used pulley wheel. If not, I should be able to find one online somewhere.

Getting that cleared and finding no damage is a pretty big relief. This should be a relatively simple fix, so long as everything goes smoothly with getting belts replaced and re-alligned.

Sidenote discovery: as I was under the engine I found a cable that looks more or less like a standard house electrical plug-in type wire. I followed it, and it turns out I have a block heater! I didn't think I had one, but man it would have been so useful a few times over the past couple months. Of course I discovered it a couple weeks before I will be moving to Phoenix where I will never need a block heater. Ha!

Try to purchase a new pulley from this site. Also, pick up some new fasteners for the application. Be glad you did not do anymore damage than you experienced. Go to startekinfo.com to get the info in regards to torque, etc... when you put everything back together. Use blue Locktite on the fasteners when you bolt it up.

__________________
Jim

There's now a stirring in the back of my head about the grade of the bolts on the pulley - check out what they are meant to be - they may not be standard 8.8s...

...if you need help with this post back and I'll look it up.

__________________
1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

Thanks for the help, everyone!

I ordered bolts and belts, so I'm good on that.

I checked around some salvage yards and benz repair shoppes today, but no luck on finding a pulley. No luck finding a new one online either.

Went ahead and bought one on eBay as that was my only option so far (plus I'm in a bit of a hurry to get this done).

Really hoping I can get everything by this weekend. I need my car up and running by Christmas, but its not seeming very likely at this point. Bad timing on this breakdown, but isn't that how it always goes?

hrmmm...actually the ebay one may not work out as the guy may not be able to ship it very quickly.

i may be getting too specific with my searching as well - can anyone tell me what crank pulley may or may not be compatible with my car?

EDIT: found what i needed. i need to relax about all of this, ha!

FYI, call Roy up top and he will hook you up on weird parts

__________________
$60 OM617 Blank Exhaust Flanges
$110 OM606 Blank Exhaust Flanges
No merc at the moment

I don't think the failure was from rust. I suspect the bolts backed out, which cocked the pulley and caused failure from "metal fatigue" (bending back & forth enough times). Good your threads are fine because pulling off the big damper wheel behind it is not easy. Lucky it didn't take out anything on the front of the engine. Last summer, on my son's 84 300D the AC belt broke (maybe from a bad RV-2 compressor), which flipped the pwr steering belt over and its rubber teeth ate thru an oil cooler hose. Must have happened close to home since still ~3 qts in the pan and the rest all over the front of the engine and hood.

Ordinarily, removing the vibration damper is very easy once the pulley is removed. It is simply sandwiched between the pulley and the balancing disc. I have never had one cause the slightest bit of difficulty.

My replacement pulley arrived today! Unfortunately I found one of the bolts sheared off and its remainder is still there in the balancer. Looks like I'm going to have to drill it out, but then I should be able to get to work with attaching the new pulley and placing the belts. Cross your fingers and don't be surprised if I'm back here looking for help later today.

Often broken bolts are loose once the head is gone. Use a left-handed drill bit and it might screw it right out.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

Have you removed the vibration damper? If not, doing so might give better access to the broken screw.

i went to home depot to pick up a drill, but unfortunately they didn't have any left-handed bits. i picked up a screw / bolt extractor, but i would prefer to try a left-handed bit first (if it doesn't bite and pull the bolt out, i'll have my pilot hole for the extractor), so i'm going to continue my search by heading to harbor freight.

qwerty - i did remove the vibration dampener, but unfortunately the bolt sheared off past it.

i'm a little concerned about getting the belts placed properly. the alternator belts are gone, so i'm a bit worried about following the proper path with them since i don't have anything to follow. not worried about the other two as they're still hanging out under the hood.