Checking the Cam Gear

Tom Wesenberg

Tom Wesenberg

Well-known member


By simply removing the small side cover over the gear, you can check the condition of the teeth, the spring tension, and check the makeup of the gear.

I'm trying to find a light rattle near the front of the engine and I was wondering if this engine had a 2 piece cam gear that was loose between the aluminum center and fiber gear. Luckily it's the good 1 piece fiber gear and it's in good condition, with no thin teeth from wear. I put a wrench behind the gear any carefully pried forward to feel the plunger and spring pressure, which is also good. This also let me know the cam nut is tight.

I still haven't found the rattle (light knock) but at least I feel good about the cam gear now. The noise may turn out to be a piston with a collapsed skirt, but that shouldn't leave me stranded either.
 
Do you have a two piece crank pulley? I just replaced one that had clicked and clacked back and forth until it had battered about 20 degrees of slop. When I took it off I also discovered that it had been broken and brazed back together at one time. It is a kind of testiment to the kind of guys who used to drive our prized little cars.
 
If you can squeeze a .010" feeler between the two gears then you can end up with a rattle.. Sometimes pushing the timing pin against the gear while running will add just enough resistance to stop the rattle so the front cover doesn't have to come for the check.. But, I know you already know this..
 
Tom, ive had the keyway slots in the crank and the pulley and the key itself be worn and even tho the crank nut is tight it will clack, and the way i check for cam gear play is, i take the dist cap off, put a socket on the crank gear and turn engine back and forth to see how much the crank turns before the rotor moves, rotor should move with the crank
 
I put the cover back on, changed the oil (Shell Rotella 15-40), and ran it and tried shorting the plugs. It doesn't sound like a serious rattle, but it does get slightly louder when I short #3 plug. It really doesn't seem to have gotten any worse in the 3 years I've been driving it, and since the sound changed when #3 plug is shorted, I'm thinking piston slap or wrist pin play. No metalic sparkles in the drain oil, just fairly black for 500 miles.
 
Have you checked the distributor drive gear for excessive wear ? I have seen this happen when either the teeth on the cam or drive gear are worn.
 
Tom,you can try dropping a couple of ounces of heavy oil down the cylinders, crank it over without the ignition on to let the oil seep passed the rings,then fire her up. This will eliminate any piston and ring noise for a short time.Then you can take it from there, like maybe carbon interfering with rings at the top of cylinder or a head gasket problem with the topof piston. This is old test I used years ago. I hope this may help you.
 
You must log in or register to reply here.
Back
Top