I have another approach to finding TDC that has worked well for me. Using the threaded adapter from a compression tester, you can put a balloon on the end of the hose coming from the adapter. Maximum inflation of the balloon occurs at TDC. It's pretty dramatic, so I'm sure it gets you to within a degree or so. I used this method on my wife's 62 NYer wagon after having little to no success with a timing light on the number one plug wire. All is well now. -----Original Message----- From: John Hertog [mailto:crossram@xxxx] Sent: Monday, September 17, 2001 8:10 AM To: Jennifer Allyn; Chrysler 300 Club Int'l Listserver Subject: [Chrysler300] Pinging & Timing and balancer problems Hi Jennie, Assuming all is working as it should, distributor advance, etc, one good possibility is that you are timing the engine, using the TDC reference mark on the harmonic balancer, and that the outer ring of the harmonic balancer has slipped . I find this to be a common occurence these days, with more balancers being "bad" than good ! I have a PILE of bad balancers from various 413 - 440 Mopars . Do not assume that the TDC mark on the balancer is where it should be ! The balancer is comprised of two " rings" held together by a vulcanised strip of rubber, or some such. This is only visible once the balancer is removed, from the backside. Get yourself a piston stop ( one can be made from an old spark plug and a bolt, bust out the porcelain from the old plug, tap the metal part to receive a bolt than can thread in and out of it.) Then put the engine on #1 TDC going by the mark on the balancer and remove #1 cylinder spark plug and insert the tool. Thread the bolt to where it barely touches the top of the piston. Place a socket on the crank pulley and slowly rotate it one way and the other ( will be easier if you have removed ALL the plugs ! ) . By playing with the piston stop, you should be able to find TRUE TDC - the point at which the piston is at the very top, right between where it stops going up and starts coming down - and veryfy the accuracy of the mark on the balancer. TDC, of course, should correspond on the mark on the balancer. betcha it doesn't . I have some balancers that are off by 5 degrees, some by ten degrees, some by fifteen, some by more ! I recently had an engine on a stand and decided to "test" all my balancers, so I put the engine at true TDC and then test-fitted one balancer after another. For each one good one, I had four bad ones ! If balancer is "off" , then you should time the car by ear only... and probably have the balancer rebuilt or replaced. There's always a risk that the outer ring will separate from the inner one, I have heard of this happening to several of our members . 300'ly John To send a message to this group, send an email to: Chrysler300@xxxxxxxxxxxxxxx For list server instructions, go to http://www.chrysler300club.com/yahoolist/inst.htm To unsubscribe from this group, send an email to: Chrysler300-unsubscribe@xxxxxxxxxxxxxxx Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/