Balancer problem
 

http://i711.photobucket.com/albums/w.../balancer2.jpg

Sorry for the bad pic. I noticed that the stud that the tach pickup uses is shiny and has what appear to be score marks on it. The tach works OK and I can't see anything obvious when it's running :confused:

I've heard about a recall on the balancers on the W116 300SD's (I think) so this is worrysome :(

Should I shut it down until I get the proper socket to check the balancer bolt?

The cutout to the left of the "stud" is also strange to me (Not where it was drilled for balancing, farther left in the pic.) Maybe the tach pickup vibrated out of position a little? I figure if it hit hard it would have damaged something.

The scrubbing looks like it's pretty recent.

Thanks.

You need either a deep 27mm socket or a shallow one with a stubby extension to reach the crank shaft bolt. For the first time you attach this it might be worthwhile attacking the problem from under the front of the car...

If you are waiting for a socket and need something to do - remove the tachometer sensor and see if the bottom has indeed been scratched. You could also remove the drive belts from the pulley and feel if you can wiggle the crankshaft pulley.

Be a good time to change the belts. Funny how that works :eek:

Indeed - I agree. Just in case you don't know a good rule of thumb for tensioning a belt is to adjust the pulleys until you can turn the longest stretch of the belt by 90 degrees. You should be able to do this with relative ease - don't tighten like a piano wire!

Sorry, I lost you there?

A better "rule" would be to use a tension gauge. First time you do that, you will be convinced of the worthlessness of the various shade tree methods.

True true but then it wouldn't be a rule of thumb anymore - can you recommend a decent tension gauge?

In an affordable price range, there is the Gates (aka Kriket) 91107 gauge for V belts, 91132 for serpentine belts.

http://www.********.com/catalog/moreinfo.php?pk=101690

I've never uses a tension gauge, I just tighten until it's "good enough".

But, if you think about the stresses that belts put on your crank hub and bearings on driven components it's not a bad idea to make sure it's right.