MTFCA Forum

My '26 roadster started up just fine for the season, except for a noise that seemed to come from the Bendix drive. I took off the Bendix cover thinking that a screw or bolt might be loose, and did not fine that.I put it back together and it still made the noise. It seems to be two knocks with an interval, and then another two. Any suggestions as to what it might be? I keep this T at my camp on a lake upstate, so it isn't right on hand. BTW the engine runs OK.
Jon Hall
Portland, Maine

Is the interval equal to the time it takes to turn the engine one revolution? If so, it might be something other than the Bendix that is causing it.

Could be the spring loaded drift pin on the Bendix counterweight is missing or stuck.

That little friction making piece keeps the Bendix gear from running forward on the screw shaft back into the ring gear.
The knocking may be the gear running into the ring gear and bouncing back off.

I had the same thing happen. Thought the starter shaft was bent, so took of the cover for a look. All OK and shaft running straight. It turned out that the Bendix cover just needed to be centered more accurately. There's not much clearance between the cover and the bolt securing the Bendix spring.

Jon, there is very little clearance between the bendix cover and the spring retaining bolt. The bolts need to be the special type with the head just half the thickness of usual bolts. Check the inside of the cover for any register marks where things may have come together.

Occasionally, I come across bendix springs which are heavier than standard T issue. This will also position the bolt heads closer to the cover due to the thickness of the spring.

Allan from down under.

Jon,

When you say 2 knocks, then an interval, then 2 knocks, etc., it makes me think that you have a couple of bad teeth on your ring gear. If the trouble were in your bendix, it would knock at even intervals, (e.g. * * * * *, versus **....**....**....**). If you remove the bendix and have someone crank over the engine slowly, while you inspect the ring gear, you may find the problem. Then you have to decide whether it's just a worn out ring gear or if something came loose and damaged it.