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  #31  
Old 01-27-2008, 03:58 PM
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Quote:
Originally Posted by babymog View Post
No dream Kerry, it happened to my Father's Lexus, the rubber failed and it lost drvie to the serpentine belt, ... clever design that Toyota stuff.
Plenty of cars have have a one piece pulley/damper/balancer arrangement where the pulley is bonded along its inner circumference. With that design, it is indeed possible for the pulley portion to "disconnect" and spin independently of the crankshaft. But the engine in question is of a significantly different design. A failure comparable to that of your father's Lexus is not possible.

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  #32  
Old 01-27-2008, 04:32 PM
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So I got a little fresh with the cap screws and they all came out. None were broken. The belts are all off and at this point, the balancer has a lot of play in it. It spins and wobbles.
I'm having some trouble getting the 27mm headed bolt off. I tried the method suggested above (shoring up the breaker bar and hitting the starter) but I need to get a helper to hit the starter so I can see what's going on. The nut seems to be moving when the starter turns the motor so that's encouraging in so much as the crank doesn't seem to be broken. The slots for the pins may be another story.
Ok, breaks over.
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  #33  
Old 01-27-2008, 05:26 PM
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I want to be sure that future readers of this thread understand that there is a rubber part that can fail on the vibration damper. If it fails, a metal portion of the vibration damper can disconnect and can flail around outside the pulley's.
This does not mean that the pulley's are loose or that the harmonic balancer is loose on the crankshaft. In the thread that I linked, such a failure occurred and the original poster was mislead by advice indicating it was a failure of the pulley or balancer that needed immediate repair. He drove it quite a ways with a separated vibration damper and did no further damage.
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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
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1993 GMC Sierra 6.5 TD 4x4
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  #34  
Old 01-27-2008, 06:02 PM
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Update...
Got the "vibration damper" and "balancing disc" off. The two steel pins were sheered lengthwise. The pieces remaining in the balancer were intact and I used a center punch to drive them out. The other half of the pin was broken into small pieces.
The groves in the crankshaft look good. I used the piece from the balancer to check the fit on the crank and it looks good. I think I got really luck here.
While I've got everything apart, I'm planning to do the following preventive maintenance:
new cap screws
new main bolt and cup springs
All new belts (hoses are in good shape)
replace water pump
thermostat
front main seal and spacer
AC compressor (has a leak)
I was thinking about the alternator but I'm going to wait on that for now
Any other things I should take care while I'm in this deep?
By the way, I didn't find a rubber spacer when I took things apart. I've got the parts soaking now and I plan to have a closer look later.
Thanks for all the help.
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  #35  
Old 01-27-2008, 06:14 PM
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James, you need to buy a lottery ticket today. Do you have any idea what caused the dowel pins to shear? Seems like it would require a lot of force.
If you click on the thread I linked earlier, it shows the vibration damper which has a rubber component.
Were you able to get the 27 mm bolt out using the starter?
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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
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  #36  
Old 01-27-2008, 06:18 PM
t walgamuth's Avatar
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Reinstalling the pins will only work if the keyways are not wallowed out. If they look good the installation of the dowell pins is a tricky process. If it is not done exactly correctly the keyways will be damaged and a new crank is the only true and permanent fix.

Tom W
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  #37  
Old 01-27-2008, 06:34 PM
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I removed a "balancer" you talk about, held by the two pins on the snout, from an OM617 engine I was dismantling yesterday. I'm surprised those pins can shear like that. It took quite a bit of force to remove it from the crank with a puller.
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  #38  
Old 01-27-2008, 06:38 PM
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Yes, I am thinking it was probably not installed correctly allowing it to wiggle enough to destroy them. In which case the keyways are probably wallowed out.

Oh, BTW wallow is a term referencing hogs wallowing in the mud, for any city folks not getting the meaning.

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.
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  #39  
Old 01-27-2008, 07:02 PM
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Quote:
Originally Posted by t walgamuth View Post
Oh, BTW wallow is a term referencing hogs wallowing in the mud, for any city folks not getting the meaning.
Thanks, but us city folks have been watching the presidential primaries, so we understand.
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  #40  
Old 01-27-2008, 07:39 PM
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Pictures?

Pictures, pictures, we all need pictures.
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  #41  
Old 01-27-2008, 08:23 PM
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Quote:
Originally Posted by jamesNB View Post
Update...
Got the "vibration damper" and "balancing disc" off.
Did the balancing disc slide off easily?
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  #42  
Old 01-27-2008, 10:44 PM
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The balancer came off pretty easily. I didn't need to use a puller. There was a lot of front to rear movement and I just gave it a nudge with a socket extension to get it the rest of the way off.
As for a reason for the failure, I'm thinking the big bolt wasn't tightened to proper torque or the cup spring flattened out and the bolt loosened up. The cup springs look more like flat washers.
I've got some pics but I need to resize them to post them.
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  #43  
Old 01-27-2008, 11:03 PM
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Originally Posted by jamesNB View Post
The balancer came off pretty easily. I didn't need to use a puller.
Then you probably need a new balancer. Hopefully, the balancer took the hit and not the crankshaft.
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  #44  
Old 01-27-2008, 11:28 PM
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Vibration Damper. No Rubber part between damper and balancer unless the black gunk is all that's left of it.


Sheered Pin. The halves that were still in the balancer.


CrankShaft Snout. The edges of the groove look sharp but you can see some wear from the broken parts. I have no idea what the goo is on the upper left of the housing. Maybe gasket silicone from a previous repair? Any ideas?


Balancer. The grooves look sharp.


Cup Springs, cap screws and the big bold (18mm dia, 27mm head). I haven't cleaned them. Note, no washers on the cap screw. Manual states they stopped putting washers on them Jan 1979.

Let me know your opinions on the grooves in the crank and balancer. Do they look ok? Or should I start looking for a rebuild engine?
If the crank needs to be replaced, I would lean toward doing a rebuild.
Attached Thumbnails
Engine running; no belts turning, no pulleys turning-balancingdisc-2_uhyfty_1.jpg   Engine running; no belts turning, no pulleys turning-capscrewsbigboltcupsprings.jpg   Engine running; no belts turning, no pulleys turning-cranksnout.jpg   Engine running; no belts turning, no pulleys turning-sheeredpin.jpg   Engine running; no belts turning, no pulleys turning-vibrationdamper.jpg  


Last edited by whunter; 01-28-2008 at 12:02 PM. Reason: attached pictures
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  #45  
Old 01-27-2008, 11:38 PM
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All grooves look ok to me. I'll be curious to know what other people who have worked on these components have to to say.
Can't figure out if your balancer is the same as the one pictured in the thread I linked on which the rubber separated.

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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
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