Harmonic Balancer Bolts Broke Off

[sgosine577]

I have a 1988 Mack Mr600 with an E6 engine. The bolts holding the harmonic Balancer broke off. What would cause this, and what are the torque requirements for the the new bolts when I install the new Harmonic Balancer.

[fjh]

I have a 1988 Mack Mr600 with an E6 engine. The bolts holding the harmonic Balancer broke off. What would cause this, and what are the torque requirements for the the new bolts when I install the new Harmonic Balancer.

I don't remember the specs for that but I would guess somwhere in the hood of 50 foot pounds they are 7/16 bolts! DON'T REUSE that damper REPLACE IT if that came loose out of the blue somthing is wrong and its likly the damper its self!

[GreenGiant2]

I don't remember the specs for that but I would guess somwhere in the hood of 50 foot pounds they are 7/16 bolts! DON'T REUSE that damper REPLACE IT if that came loose out of the blue somthing is wrong and its likly the damper its self!

i jusy read that cummins say's you should replace the harmonic balancer every 380,000 miles

[rhasler]

i jusy read that cummins say's you should replace the harmonic balancer every 380,000 miles

ReMack engines come with a warning label to check the dampner before installing it on a rebuilt engine, but I don't think they give any specific criteria for replacement.

[theakerstwo]

ReMack engines come with a warning label to check the dampner before installing it on a rebuilt engine, but I don't think they give any specific criteria for replacement.

What is macks way of checking one. Cummins and DD i know about but never did know how to check a mack. Only way i know would be mic it.

[rhasler]

What is macks way of checking one. Cummins and DD i know about but never did know how to check a mack. Only way i know would be mic it.

Mostly just a visual inspection involving checking for bulging, cracking, splitting. or distortion of the casing. I would imagine that the same checks made for Cummins or Detroit would be more than adequate for Mack's dampners. I'm not sure who builds the MP/volvo engine dampners, but I remember reading that back when Holset was independent, back before they were making turbos and compressors, they were the supplier that volvo had chosen for their dampners. If I remember correctly that was why Cummins bought Holset in the first place, in order to get their foot in the door at volvo.

[theakerstwo]

And speaking of Holset i have a E7 engine here that has a Holset compressor on it. First for me.I guess you have seen alot of them.

[rhasler]

And speaking of Holset i have a E7 engine here that has a Holset compressor on it. First for me.I guess you have seen alot of them.

I know that Mack used some Holset compressors but can't remember seeing an engine with one. I imagine it was an option that didn't have widespread acceptance.