LutzTD thats pretty much what I did. I cleaned everything up really well and headed off to the auto parts store. I got the harmonic balancer installer and a BF Torque wrench from O'Reily's, you just put down a deposit for what the tools are worth and then you get the full refund when you bring them back, pretty awesome if you ask me. I also got some JB weld, red max strength loctite and blue medium strength loctite. I lined the HB with the crank as best I could and then went a little bit back(counter clockwise) so that when things get tight it would drag the slots into place. I had to use a block of wood and a 2lb maul to tap in on just enough to start using the HB install tool. Come to find out though the install tool didn't have the right adaptor so I had to use the 27 crankshaft bolt to pull it on. I really didn't want to do it that way but I felt pretty confident because it screwed in aways before it started to pull the HB in. I tightend it aways and took the bolt out to check the pin/dowel holes, they were a little off already so I used a block of wood and the 2lb maul on the edge of the HB and tapped it back a little more counter clockwise from the holes. What worked best for me then once I had it in enough was to take the bearing from the HB install tool set and sandwich it on the 27 mm crankshaft bolt between two of the cup spring washers. That way the bearing would turn with the bolt head but wouldn't put much drag on the HB itself. Once it was all the way home I filled the holes with JB weld and hammered the pins in. It took some doing and I used a punch at the very end to get them under the lip of the HB but all and all I feel pretty good about the connection. I backed the 27mm bolt out put the red loctite half way up the threads on one side and tightened it to 250 lbs. I know the FSM says to use motor oil but because of the loctite I used brake cleaner on the bolt and the crankshaft and made sure they were both clean and dry. I figured the torque should be the same if not just a little more while using loctite instead of motor oil. Then I put the pulleys back on after cleaning up the 6mm hex bolts and putting the blue loctite on that. I am going to let everything sit, take my kid to the zoo tomorrow, then put it all back together either tomorrow afternoon or Saturday. Wow that got long. Thanks for all the replies and advice I sure learned a lot from this one and I guess if it happens again LutzTD will have to borrow his drillbits and bracket!

you put red loctite on the crank bolt... it's not going to come out again EVER! that stuff requires 700°F to loosen. IF it anaerobically sealed.

I think BLUE would have been sufficient! oh well. I DO not envy the next guy to work on that balancer!

__________________
John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 560SL convertible
1987 190D 2.5-5SPEED!!!

1987 300TD
2005 Dodge Sprinter 2500 158"WB
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

Well that guy will be me, lol. Drastic times call for drastic measures and after all the reading I did about the pins and bolt failing the second time, which almost always destroyed the crankshaft, I figured I would have to take my chances.

First time my HB failed was a day or two after the local self proclaimed A/C expert tried to test my A/C compressor by hot wiring the connector leads to the battery to activate the clutch with the engine running. When he did that the seized compressor stalled my idling engine. HB failed the next day after 30 kms of driving. I was scratching my head for awhile trying to figure out why this HB failed but after finally remembering the seized compressor incident the day before it happened I think that might have been the cause. Second time the balancer failed was my fault. I did many things wrong on reinstallation and was supplied with the incorrect washer for the main bolt from the dealer.
I am on the third repair and still holding. I used lots of blue locktite on the cranksnout and dowel holes. I tightened the main bolt with a breaker bar and gave it two small taps with an air impact.

After following many similar threads on the subject including this one I think maybe I am lucky my third repair is still holding. I always learn something new from this forum of communication between similar owners.

I am now very curious if the internal thrust washers of our engines could play a part in this harmonic balancer problem even though I think I know why mine failed originally.

I hope your repair works out and am wondering if you changed that front crank seal and spacer ring before you put it all back together with red locktite? It sounds like with the red locktite this was a one shot opportunity. I am glad I used the blue stuff. I did not realize that the red locktite was more or less permanent. I knew it had a stronger bond and that a torch was required to release it but had no idea of the heat range required to loosen it. Maybe the forum should paste a notice about that for future circumstances and do-it yourselfers that are'nt all that fmiliar with the locktite strengths. Some of us don't work around the stuff very often. I know I contemplated it at the store when I purchased the blue stuff. I had red in one hand and blue in the other hand and it could easily have gone the other way for me too.

Macdoe, sounds like you've had some practice with this then, lol. I am glad your last repair has held up and thanks for the luck on mine. I remember reading before that the a/c compressor was at fault for some other crankshaft bolt failures. Too bad the belts have to be so darn tough! Yes I replaced the spacer and the seal I sure didn't want to tear all this stuff out again for a couple 10 dollar parts. As far as the red vs blue I was more concerned about it wiggling loose then getting it off later. At the parts store I read the back of the packages and choose the red for the crank and blue for hex heads. Here is the info for

Blue

PERFORMANCE OF CURED MATERIAL

(After 24 hrs. at 72

Typical
Value Range

Breakaway Torque, in.lbs 115 70 to 150
(Nm) (13) (8 to 17)
Prevail Torque, in.lbs 53 25 to 60
(Nm) (6) (3 to 7)
Where Breakaway Torque is the force required to initiate the
fastener movement and Prevail Torque is the force required to
disassemble the fastener once Breakaway Torque has
occurred.

TYPICAL ENVIRONMENTAL RESISTANCE
Temperature Resistance

Product temperature range from -65

Chemical / Solvent Resistance

Aged under conditions and tested at 72

Temp 1000hr

Hot air 150

Motor oil (SL) 125°C 21

And the Red

PERFORMANCE OF CURED MATERIAL

(After 24 hrs. at 72

Typical
Value Range

Breakaway Torque, in.lbs 175 125 to 350
(Nm) (20) (14 to 40)
Prevail Torque, ) (in.lbs) 230 200 to 350
(Nm) (26) (23 to 40)
Where Breakaway Torque is the force required to initiate the
fastener movement and Prevail Torque is the force required to
disassemble the fastener once Breakaway Torque has
occurred.

TYPICAL ENVIRONMENTAL RESISTANCE
Temperature Resistance

Product temperature range from -65

Chemical / Solvent Resistance

Aged under conditions and tested at 22

Temp 500hr 1000hr

Hot air 150

Motor oil (SL) 125°C 42

This information is right from the permatex website. And while reading this info at the parts store I figured I would rather over due it a little than under do it. As stated above the ft lbs to remove red is 350 max after 24 hours. That number drops to 41% after 500 hours of heat which is then 143 ft lbs. Compared to blue after 500 hours of heat 70.5 ft lbs. This is all the max so even considering if I got everything clean room clean it shouldn't be impossible to get off later with a bigger bar and a little more heat.

Now all this went through my head while the parts guy was over my shoulder with his two cents. This is what I did and why I did it. Hopefully I won't be too sorry later but only time will tell. I am not ashamed of my many many mistakes in life as long as I can learn from them!

That's some great info to have...it does'nt actually sound that bad if you did need to take it apart, and good to hear you did the seal too.
It is such a shame that something trivial like the HB can take out such an otherwise "over engineered engine" I know it was a real headache for me, but sometimes I guess you gotta just make it work however.
Since it happened to me I always find myself attracted to these HB threads. I was troubled to read on LUTZTD 's failure. I think he did the most comprehensive and correct repair to his that I read on here and it still failed.....discouraging for me too. Reading that thread inspired the Mcguyver in me in many aspects of repair since read.
I will be still crossing my fingers and knocking on wood that these repairs hold up.
I suppose it would'nt hurt to have a back up short block handy if the need arises.
AN alternative like a fluidampr would be nice to adapt somehow, but would probably require alot of research and re-engineering.
Any one ever heard the official word from Mercedes as to the causes of this? German accent prefered?
Thanks again for the Locktite specs, packages are long gone...and it's now here for reference.