Re: Harmonic Balancer - how can you tell if it's working?
It's something that I noticed recently this year. Always had a vibration of sorts, nothing horrible, but I think this 2k vibration was masked by other suspension driveline issues. Over the winter I replaced the entire suspension front to rear, along with the driveshaft (Denny's'), u-joints, springs, control arms bushings, front tie rods, shocks, you name it....complete refresh...handles great.
Because of that I was convinced it was a driveline vibration, most notably a pinion angle. I had moved the angle up and down a million different positions and it didn't go away. But only last week by chance I did the old drive down the road, put it in and out of gear, clutch in and out a number of times at differenet speeds and finally realized it wasn't a driveline or speed related issue at all, but definitely from the rotating engine....it's always at 2000 rpm.
It's most noticeable as a "shutter/shake" type feeling as it passes through the 2k mark on a deceleration. It's repeatable every single time. It's a lot easier to notice when I am actually in gear and using the engine to slow me down. By just driving along, pushing in the clutch or taking it out of gear and revving the engine it's a bit tougher to feel because the driveline connects everything to magnify the vibration. Even sitting at a standstill and revving it, or coasting out of gear it is tough to notice for you pass through the 2k mark in a second. But if I take the time and hover up and down the 2k mark I can feel it, not as pronounced as when in gear driving, but definitely appears to be the "source".
I am going remove all the belts some time this week to see what happens. I did remove the alt belt and drive it down the street, but scared as all heck that I'd melt the engine with no water pump or fan...engine was already warm. I'll try it again, but with the engine cold to give me a bit more time to isolate it if at all possible.
Any other thoughts?
'72 Chevelle, 350SB, M-20, 12 bolt 3.07 pos, 600 CFM Holley 4160, Performer RPM Man., 2.02/1.6 heads, #2102 Cam, Mallory HEI, DynoMax 2.5" Ceramics