help please with loose part on front of my 300SD's engine
 

There is a circular disk shaped object right behind the pulleys on the very front of my 1983 300SD's engine. It makes quite a racket, and i have parked the car untill i can figure out if it's ok to drive it or not. The part can be moved around by hand, and it almost looks like a pulley shield or something to that effect. How critical is this part? can the car be driven with it loose? Taking off all the belts/pulleys etc does not sound fun especially in a dorm parking lot, so if it's ok to drive for a little while i'd much prefer that. Thanks in advance,
Ryan

I agree with TXBill. Sounds like vibration dampener or pulley problem. I've seen an SD throw these off before (bolt shear). Can toss the fan into the radiator.

man, i'm in one big dilemma now. Spring break is in a week, i have no clue which shops are reputable up here, and i have no money to pay anyone to fix it. Yet, i have to get the car home, which is 300 miles away for spring break, or else i dont get home for spring break. Time to call me padre and see if he has any fatherly words of wisdom for me. This sounds like it's gonna be expensive........... thanks for all the help guys,
Ryan

just talked with my dad, he thinks it's best for me to just completely park it and then run it home. He said and i quote "say a couple prayers before you leave and go". Lets hope the old girl has the same homing instinct as it's shown in the past......
Ryan

Sorry I appeared to be out of the loop. Had to make my 2 hr commute home. Ryan: I sent that information to you via e-mail as discussed. Good luck.

My friends car was missing a few of the bolts that hold the pulley on. By the time he could hear it, more had been sheared. Ended up towing to my favorite Indie who had to pull the balance ring to get the broken bolts out.

Ryan:

If you have a chance, see if to can check the tightness on the 6 bolts that hold the pulley on. If any are missing, try to replace them prior to attempting to make that trip home. If loose, I do not believe you will get too far.

If you are not comfortable with doing it yourself, take it to a full service gas station or something. I believe Lowe's Home Improvement carries automotive grade metric bolts in the "hardware" isle. The bolt size is on that R&R sheet I sent you. Wish I could help you more.

-Scott

Ryan,

You are taking a chance on causing more damage to the car than the car may be worth if you run the engine with a loose harmonic balancer. If it doesn't sound right, don't drive it.

EWS

I agree with EWS. Things are going to get much more expensive in a hurry if you drive that car. I think there is a VERY high probabililty it will not last until you get home and when it does fail, you'll be digging deep into someone's bank account to get it fixed. Better to take a bus home if you can't afford to fix it right now.

I had an issue once on my 300D (same engine), where the large bold broke several times.
What I don't understand, is, if the harmonic balancer is freewheeling, what is making the pulleys turn?
Isn't the pulley bolted into the balancer? (six bolts)
If indeed the balancer is loose, then its probably one of two things. Either the bolt broke (with luck you can get the rest of the old one out), or, the two shear pins broke. If the shear pins broke, that can be fixed with new ones (might as well get the new large bolt that goes in there too). However, if the little slots for the pins are all slopped out (for lack of a better term) then the pins won't sit tight, and could possibly break out of there way too soon.

my input...for what its worth at 2 am. :D

-Larry

if this does fail, other than the fan flying into the radiator(which i will obviously hear and feel) what damage will be done. If it goes into the radiator i will just shut it down and coast off to the side, and have it towed from there. I presume the belts etc will be pretty trashed as well right? So basically, i'm asking for what would probably happen if this thing lets go with me going 85 down the interstate, thanks once again for everyone's help and insight, it's greatly appreciated.
Ryan

From what I gather reading other posts about the harmonic balancer, the most expensive damage will not be the radiator. It will be the two grooves in the crankshaft that hold the pins which secure the balancer. If you damage these slots there is a good chance you may need a new crankshaft or at least significant work to resurrect the slots. So if you don't mind pulling the engine to replace the crankshaft, drive it home. If you have any hesitation about pulling the engine, jump on a bus.

DON'T drive it. You can do an lot more damage. If you can afford to have it towed if it breaks down, you can afford to have it towed before it breaks down.

Have it towed to a local repair shop and fixed before you have a candidate for a junkyard.

P E H

This thread reminds me of my very religious former brother-in-law. He was moving his family a long distance in an old Chevy schoolbus. The engine started to knock about halfway through the journey. (As it turned out, the oil line running to the rocker shaft had broken). My brother-in-law could not diagnose the problem so he decided to pray for God to heal the engine. After the prayer, he continued down the highway. A few miles later, the engine threw a rod. That he could diagnose, so now he was in good shape!
If God couldn't fix a simple broken oil line, he sure can't get the harmonic balancer reconnected. TAKE THE BUS.

alright, it's time to have another talk with the "father". I didn't realize that if this thing gets thrown it could cause me to need a new crankshaft...that is not something i want to even think about. Thanks for all your help,
Ryan

Kerry,

Shows the power of prayer. If it isn't something altering a person's mind that can be made to appear that something is fixed, prayer won't work.

If it did, we wouldn't need mechanics or MBs. Volkswagens and Cavaliers would last for ever. Just pray and your car will be new again.

P E H

Continental Imports
 

Your in Gainesville right? Try Continental Imports. I had my car towed to them when it flat out died at the rest stop on 75 just south of Gainesville. Starter just died out of the blue and nothing would bring it back to life. Charged me $140.00 for the starter, $55.00 labor. Clean shop, honest people. Was towed in at around 4pm in the pouring rain, had me back on the road by 5:30.
So here is at least one honest shop around your area.

RG5384,

Doesn't one of your friends have a car and a chain or a rope? It would save you a few bucks if you could get your MB to a garage that way. If you can find a pipe to put the chain thru it will prevent you from running into the tow car. Remember the brakes don't work very well without vacuun assist. You should keep your left foot on the parking brake.

P E H

none of my friends have a car capeable of towing my car, and unfortunately i'm in jacksonville, not gainsville. there is a shop about ten minutes away that i'll probably have the car towed to. Dont think i'm risking driving it home anymore, thanks for everyones help, and if anyone has any more advice i'd love to hear it. Thanks,
Ryan

I think that is a wise decision Ryan. Hopefully the repair will not be too expensive. Post a follow up after the shop has had a chance to look at it. We'll all be interested in more information on the failure mode, especially those of us with 617.951's.

-Scott

well, unfortunately my wise decision has been veto'd and once again i'm driving the old girl home. I'm really nervous about making the trip especially after reading everything on here, but we do not have the money to pay someone to repair the car, and i have the knowledge to repair it myself(with the exception of statically ballancing the new dampner), so IF it does make it home that will be the only labor charge. I'm going to check the six bolts on the fan before i leave, and hopefully have one of my friends who is in training to be an ASE mechanic give it a once over, then just make very minor throttle changes and drive it really easy and hope she gets me home. If it does fly off during the trip, i guess we lost this gamble(i'm well aware the odds are not on my side as it is). Would there be any better chance of making the trip if i were to drive say 60-65 instead of 80-85 on the trip home? Thanks again for all your help, and i do realize i'm taking a big gamble right now, but unfortunately it seems my only solution. If i dont drive it home the car will be parked for a few months up here, and school gets out at the end of April, so any way i look at it the car has to get home. Towing it from here to tampa doesn't seem like a financially sound idea either, so this is what i'm left with. I am kind of frusterated at the car because of this though, this is the type of problem i would expect from my old buick, and my switch to a mercedes diesel was to avoid problems like this, guess it's all in the luck of the draw. Thanks once again, the car is now officially parked untill friday where i hope to get her home.
sincerely,
Ryan

one more real quick question: is there any way that the driveshaft i hit in the road a month or two ago has anything to do with this being loose/broken?

Ryan:
I don't get it. If you have the ability to fix the car, why don't you do it before you leave? If you do a search on harmonic balancer on this site you will find a number of posts, some of which describe the difficulties involved if the notches for the pins get damaged.
Pulling the radiator to get access to the area should only take a half hour or so.

Kerry

the reason i can't fix it here is i am in a dorm parking lot, without proper jacks, and i also dont have all my tools with me. i have no way to drain the fluids so that a racoon etc will not die from the radiator fluid etc etc. Basically, this is not a job i'm legally allowed or willing to do in a dorm parking lot. Any ideas on ways around this i'm all ears. I'm talking over AIM with a friend who's dad is a service tech at a mercedes dealer, so hopefully i'll get some more insight there. Thanks again for everyone's help
RYan

And what when your MB breaks down after 50 miles? All of a sudden you have the money to tow it 250 miles? The towing will cost more than the repair if you do it before it gets worse.

If you don't have the money for a tow home, what will you do with the car? Leave it along the road until April? It would probably be scrapped by then. It would be better to leave it in the dorm parking lot now.

That's not a big repair to do outside in FL where its warm. You are going to be sorry if you lose the car when you wouldn't have to.

As for driving it home, slower would be better. It will be much easier to find the parts when they fly out.

P E H

Ryan:

Your long message raises an important question. You make reference to tightening the 6 bolts that hold the fan on.

The Main pulley with the vibration damper, harmonic balancing ring, and crank shaft is not the same pulley as the pulley the fan is on. The fan pulley is directly connected to a viscous coupling mounted off the water pump shaft.

I'll send you some more info. This distinction will be critical for your dad and the MB Technician.

-Scott

I read something on this site that led me to beleive that the dampner was two peices of metal held together by a rubber compound. If that is true, only the front half of the dampener is loose, as there is an almost identical circular ring sitting right behind the loose part, that is still held on tight. My friend that i was talking to also made the distinction between the bolts that hold the fan on and the bolts that hold the pully and damnper on. I'm going to look tomarrow to see if the bolts are still there, or if they have fallen out or sheared off. The pulley itself is not loose, which is what is confusing me, i would think that if the dampener were held on with the same bolts that held the pulley on, if the dampener were loose wouldn't the pulley also be loose?. I might be able to fix this at a friends apartment that friday evening or saturday, so i wouldn't have to drive a broken car home. Thats my best looking alternative at the moment.
Ryan

Ryan:
I looked at the pictures in my Mercedes shop manual. There are two parts in addition to the pulleys. There is a balancer and a vibration damper. The balancer is attached to the crankshaft as I described in the prior post and then the vibration damper goes on before the pulleys. The six bolts go thru the pulleys, and the vibration damper, screwing in to the balancer.
I still cannot picture these three parts separating from each other unless all six bolts came out. If that was the case, the belts would not turn.

thats the thing that is confusing me the most right now as well, from everythign i've read my pulley should be about to fall off. The only indication i've had that the pulley might be loose is a very very slight wobbling of the belt that runs to the power steering pump. I'll know more tomarrow when i look at it, and my friends dad is sending me the shop diagrams for the entire system tomarrow when he's at his work. I'm also going to call a mercedes specialist up here and try to talk to them about it, and my dad is going to look through some maintenance books(For a W123, but same engine) tonight and then go talk to a mercedes specialist accross the street from his work. I'm gonna try to find a girl with an old compac and take out the mirror and put it on a pencil so i can look around down there also. I can't tell you how much all of the time and effort everyone has put into this means to me, i can't thank you all enough.
Ryan

Ryan:
I don't think you should need a jack for this job. Everything shcould be accessible from above or easily from below without lifting the car.
I can't see any indications of there being two parts to the balancer in my Haynes manual. The balancer is slid over the end of the crankshaft, held in position by two dowels which fit into mating half slots in the balancer and shaft. A large bolt which goes directly into the end of the crankshaft secures it in position. The pulleys are then bolted into the balancer with six allen head bolts.
So, to figure out what it going on you are probably going to have to remove the radiator, loosen the belts, remove the six allen head bolts and then the pulleys should come off. You should have a clear view of the balancer at that point.
Something seems a bit odd to me about your description of the problem. You describe the situation as if the pulleys are still fixed in place but the balancer is loose. From what I can gather from looking at the pictures in Haynes and reading the assembly/disassembly process if the balancer is loose, the pulleys should be loose also because they are bolted to the balancer. Are you sure it is not the pulleys that are loose? If it is the pulleys, the repair could be as simple as tightening those allen head bolts.

You might have to only tighten the large bolt with the 27mm head. A 1 1/16 inch socket will also fit. You can do this without taking out the radiator or anything else. It would certainly be a good place to start. Turn clockwise to tighten.

The engine might turn so if you have a manual shift, put it in high gear with parking brake engaged. If automatic, you will have to hold the balancer, possibly using a vise grip plier clamped on it.

P E H

I want to point out that the two metal dowels are not exactly 180 degrees apart. One is just a smidgeon closer to the other. Depending on which side is up, its more like either 182 or 178 degrees. Along with the compact, you will want to have a flashlight, so you can see something.

I am trying my darndest to remember if it is one solid disc, or if it has an inner and outer ring, held together by some sort of "stuff".

IF...it does end up breaking, and you shear the big 27mm bolt, you will loose your alternator, your a/c, and your waterpump. Then, your only choice would be to remove everything that is loose and dangling around, and turn on the heat (aux. waterpump will circulate coolant through the heater) and idle along for a few hundred yards (or when ever it gets too hot - but you cant be sure, because the thermostat isnt getting its usual amount of fluid passing by, so you won't have an accurate reading) and then wait till it cools down, and drive a little bit more - repeat this until you get to Tampa. You should be here before summer is over.

I am sorry to hear that this is happening to you and your Benz. Especially since you are stuck somewhere else but home. I do wish you luck, and a safe passage home.

btw...might want to call around for a used balancer/dampener.

-Larry

more info
 

well my curiousity wouldn't have let me sleep tonight if i didn't pop open the hood and play with things a little bit. The pulley IS NOT loose, it seems very tight, as do all the belts. The part behind the metal ring in question is tight, i cannot move it with my hand. i tried to move the pulley any way that i could, and it would not budge. I was wrong in that i thought the viscous fan was attached to the crank, obviously(as many of you already know) it is not. The part in question is the metal disc shaped object DIRECTLY behind the various pulleys. I can turn it, move it up and down, wiggle it back and forth, i can move it every which way. It appears as if the object behind the loose disc had some sort of a rubber sealant on it that connected it to the loose disc. Once again, nothing off the crank is loose other than this one disc. I'm more confused than ever now......:confused: :confused:
Thanks for all your help once again, and i'm going to go look in the daytime tomarrow and see if i can determine anything else.
thanks again for all your help,
Ryan

after looking at a blown up image of the entire pully system on the crankshaft, it LOOKS to be as if there are two separate peices to the vibration dampner. According to the CD manual diagram, the part that i am visibly seeing as being loose is not attached with any bolts, but rather some sort of black substance(per diagram). Can anyone confirm that the dampener is in fact two peices held together by a rubber type substance?
thanks again
Ryan

The vibration absorber (official name ;) ) , a "rubbery stuff",and the counterweight, a metal "plate, are aligned with two dowels and then attached to the end of the crankshaft by the 27 mm. (1 1/16") bolt. Torqued to a gazillion newton-meters. The rubber deteriorates sometimes and this sounds like your problem. Do not drive without checking out the bolt. See why here:http://www.peachparts.com/shopforum/tech-help/58187-crank-pulley-balancer-how-did-come-apart.html?highlight=vibration+crankshaft

if this bolt checks out is it safe to say the car is driveable?

If it is loose (ie that's the only problem) and everything lines up (dowels) and you can tighten it (lock the flywheel) to 200 ft-lbs.; then it might do the trick. I'd check out this thread:http://www.peachparts.com/shopforum/diesel-discussion/29387-haromonic-balancer-note-caution.html?highlight=vibration+crankshaft+harmonic and this one:http://www.peachparts.com/shopforum/diesel-discussion/22647-failed-123-diesel-harmonic-balancers.html?highlight=crankshaft+harmonic

thanks for all your help. My looking at this picture(if it works, sorry about the poor quality, i had to get it within the size specs), it appears as if the part that is loose on my car is not bolted down at all, but rather simply held on by the rubber "stuff". It looks by the diagram as if the other part of the dampner is held on by the six bolts, and that the metal part that is loose on my car is simply glued to the other part. The part in question is number 20

The picture is fine. Appears the vibration absorber has separated AFAIK, unfortunately. Iwould assume replacement is the only option, but must admit I haven't ever dealt with a failed one, only ones intact. Larry Bible would have insight on this, hopefully.

Should I stay or should I go?
 

Since that thing is seperating, and the outer ring has come loose.
It is just a matter of time until the balancing ring starts walking off
and does a really cool "hole-saw" demonstration on your timing case cover and oil pan. The last one of those I fixed ran about
$2000. You may want to re-think going for broke.
Broke is how most people end up after driving damaged cars.
Good Luck.
-DR.D

P.S. - MB Roadside Assistance. 1-800-FOR-MERCEDES

Randy:
In looking at the Mercedes shop manual for the 617 engine, I think your analysis may be correct. In one of the pictures it shows 'shading' between the damper and the piece through which the bolts attach the damper to the balancer. That 'shading' could be a glue or 'rubbery' substance of some kind. If that is where the problem lies, and the center bolt and allen bolts are tight, I don't think there is any damage to the crank yet.
I would say you have two choices at this point: Remove the pulley and vibration damper (I'm pretty sure this only requires the removal of the six allen bolts and not the more difficult central bolt) and replacing the damper with a new one or a used one from a junkyard. The other option, which may be possible if you can align the vibration damper up with its original position is to get a lot of 5 minute epoxy and glue it back on if you can clean it up enough. I don't think I'd recommend this second alternative unless the first was simply impossible.
I would still be reluctant to drive it in its current condition because the vibration caused by the loose damper may loosen the balancer and screw up the balancer in its attachment to the crank.

is buying a used vibrationd dampener a good idea? i can get a new one for 250 and a used one for 150. I'm getting so frusterated at this seemingly POS car. I just spent over 700 dollars on new shocks, front tires and alignment. I can't even count the number of repairs before that. I knew that some things would nickel and dime me with this car, but i really didn't expect 500 dollar repair bills. I may sell the car after i fix this and buy like an acura integra or something. I'm done with this mercedes BS. Sorry for the rant, thank you all very much for all your help, it is greatly greatly appreciated. once again sorry for ranting but i feel better now:D
thanks again,
Ryan

I can't answer your question authoritatively. I am under the impression that the balancer is tuned to the engine and the damper isn't. I may be totally wrong on that. If I am right, a used damper would be fine.
But, $150!!--no way. A Pick and Pull here in Denver would let one go for a lot cheaper. Look around, you might be able to find one cheaper. Maybe even someone on the list has an old engine sitting around and would be willing to donate it.
Shocks, tires, and alignment seem like general maintenance items to me, so I wouldn't complain about those. But a damper, that's another question. I'd blame it on the driveshaft you hit.

you really think that driveshaft could have caused this? i had a claim in, so i dont know if i'd be able to claim that as damaged caused or not anymore

Since I've never seen a post on this list before describing this separation I'd assume something must have happened to cause it. It seems possible that the driveshaft hit the outer edge of the damper, breaking it's bond to the rubbery stuff. What other damage did the driveshaft do? Any evidence it hit anything else on the front bottom of the engine compartment?

help please with loose part on front of my 300SD's engine
 

Ryan,

I tried to send an e-mail to you earlier, but not sure if it went out. If bolts are not seized, this is not a big job. If you’re worried about fluids in the dorm parking lot, you don't have to pull the radiator unless you have to get in there with a drill for broken/stripped bolts. I did this the other night on my 300SD to replace the front oil seal. Simple tools, simple job, it could be done in the breakdown lane of the interstate if you had all the stuff with you and a little good luck. E-mail me direct at zypher@aol.com and we can trade phone numbers if you want to discuss some of the details. I may be a little hard to catch today. If you plan to drive it three hundred miles just to fix it yourself there, you are making no sense.

Charley Huff

i'm heading downstairs to triple check that all the bolts are still there and tight, and to see how hard a job it appears to be. Charles, i would love to exchange phone numbers and talk about how to do this, ill reply to your email once i get back from pokin around with my car. thanks!
Ryan

Simple procedure, except for the torque requirements to tighten the large bolt on the end of the crank. For that one you will need a torque wrench that will go over 200 ft lbs.
I doubt you can get to that bolt without removing the radiator. However, it may be the 6 smaller allen headed bolts inside the pulley. Those can be tough to see, even with the radiator out. You will need the right tools to check them for tightness.
I used a mirror to make sure they were all tighened and I used a torque wrench to get them right. Don't have a manuel here right now, but they can be easy to overtighten.

i just ordered a pulley, vibration dampener, and balancer ring from a gentleman named pat(phil from partsshop referred me-really great people) for a measly ninety dollars!! So i'm planning on doing this at a friends apt complex friday afternoon and possibly saturday, hoping to be home by saturday night. I'm going to try to rent a pulley puller and torque wrench from an auto store or something, and hopefully this will not be too hard. If i get out of this mess for under 150 bucks i'll be incredibly happy :D Thanks again for everyone's help.
Ryan

Ryan:

If there is nothing wrong with the balancing ring, use the one you have. I believe those are dynamically balanced specific to your engine.

Exchanging the vibration damper does not require re-balancing. I do not believe you will need the puller either if you just remove the pulley and vibration damper. I think these are both held on with the 6 allen head bolts.

You will probably want to remove the fan to open up the space between the pulley and radiator for tools.

Keep us posted.

help please with loose part on front of my 300SD's engine
 

Ryan,

I bought the harmonic balancer puller at Pep Boys for $9.99. Doubt you can rent much cheaper. Get one set up to place three puller bolts, and check to see which puller bolts are supplied with the kit. Mine had the right ones; I think they were 8mm.

You don't need the hub puller unless you are taking the inner most part off. The pulley and big flat disc are not pressed on, just bolted with the 6 hollow head cap screws.

If you don't have to remove the inner most part, you don't have to remove the big center bolt anyway, but if you do and do it wrong, you can break the hub.

Auto Zone will let you rent a torque wrench for free with a deposit, or at least they do here. Call me sloppy if you like, I didn't use a torque wrench. You had better know the technique for dealing with stubborn hollow hex head cap screws or you will strip the heads and make big trouble. Also, I pulled the big center bolt, the inner most hub, the seal, and wear ring with the radiator in place.

Charley Huff