driving home hear a weird pop noise have trouble turning but a few blocks from home so kept going as I was parking started over heating. Pop the hood notice a thrown belt. Upon closer inspection relize that the bottom pulley where all the belts come together is loose. Not just loose but broken off held on by the belts. The bolt heads are sheared off. This is the crankshaft pulley right? What do I do now

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"the old-fashioned German automobile design culture, which proclaims that the engineer knows best, and considers studies of real people driving their vehicles irrelevant."
Donald Norman, in his new book Emotional Design,

Arguing on the internet is like competing in the Special Olympics. Even if you win your still retarded.

let me guess..you own a 240d W123?

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Jennifer
90 350sdl

Replace the engine if it damaged the crank nose.

Go around to the back of the vehicle. Write down any numbers and letters that you see on the trunk lid.. Then let us know what they are, along with the year model.

Sheesh, you guys are harsh….

But yeah I don’t get why ppl have 3 paragraphs in their sig and none of them relate to what the hell kind of car they drive…

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Paul
Benz-less
I need an SDL !

Check his profile... Its a 1984 300D

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1985 500SL Euro w/ AMG bits 130k
1984 300SD Turbodiesel 192k
1980 240D Stick China 188k
2001 CLK55 AMG 101k
2007 S600 Biturbo 149k Overheated Project, IT'S ALIVE!!!

Look up TWeatherford's recent thread. It's probably on page 2. This is a relatively common problem with a fair number of threads on the topic. Search on crank pulley replacement or harmonic balancer replacement.

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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

In that case, go to a hardware store and puchase six (6) M8 x 30 socket head cap screws with a strength rating of 8.8 or better. (Most sold at hardware stores are 12.9 in black oxide.)

You will be very very lucky if there is not damage to the crank nose. If this is damaged its a very expensive problem to fix.

See, those bolts normally don't just break. Its a good chance that the big pulley and harmonic balancer have worked the keys around and wallowed them out and thats why the bolts sheared off.

But you might be lucky and get away with just replacing the six bolts. Its worth a try.

Tom W

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

There have been plenty of reports on the forum of the pulley bolts shearing absent any apparent problem with the balancer/crankshaft. However, it would be logical that some secondary event, like the sudden stoppage of a belt-driven accessory, could cause either problem: sheared dowel pins or sheared pulley bolts.

That brings up an interesting point. Should the pulley bolts be torqued down periodically to prevent the pulley from loosening up and messing up the key way?

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1979 240D- 316K miles - VGT Turbo, Intercooler, Stick Shift, Many Other Mods - Daily Driver

1982 300SD - 232K miles - Wife's Daily Driver

1986 560SL - Wife's red speed machine

Checking the bolt torque periodically could only be a good idea. I can't see that there is any "keyway" involved, however. The pulley simply bolts onto the balancer, with the vibration damper sandwiched between the two.

I thought there was a woodruff key in there somewhere.

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1979 240D- 316K miles - VGT Turbo, Intercooler, Stick Shift, Many Other Mods - Daily Driver

1982 300SD - 232K miles - Wife's Daily Driver

1986 560SL - Wife's red speed machine

I find it difficult to believe the bolts would just shear for no reason. An alternator freezing up would seem like a long shot to shear the bolts.

I have had ac compressors sieze before with the worst thing happening being a belt burned up.

Tom W

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

The woodruff key is between the crank snout and the balancer mating surfaces. This is locked down by the 27mm bolt. The Pulley and dampener is then bolted the the balancer.

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1983 123.133 California
- GreaseCar Veg System