I am working on an engine with a generator and the aluminum cam gear shows signs of severe wear. I suspect the gear on the generator is too close to the cam gear but what should the clearances be both at the crank/cam and cam/generator gears? Anyone know?
If you have a Ford T service manual, see Chapter VIII.
Backlash between crank gear and camshaft gear (new gears): 0.0005 to 0.003 inch at the tightest spot. If too tight at the tightest spot, check both gears for burrs and dress accordingly. If that doesn't help, try installing the cam gear 180 degrees from its original position and check again.
Old gears may show as much as 0.006 inch backlash.
Generator gear to camshaft gear clearance: 0.002 to 0.004 inch. If too tight, add an additional gasket between the generator mounting bracket and cylinder block.
One thing that will wear out a cam gear is a badly worm crank gear or a generator bracket that is installed cocked off at an angle from the cam centerline. there is no feature that aligns the generator bracket to the block other than the cylinder cover and the side f the block. Lots of times the gen bracket gets bolted to the block 1st and never loosened up or the gear mesh checked.
Dan is correct. I bolted on the generator bracket early in the engine assembly a couple of years ago When on the New Mexico tour, I noticed the cam gear was damaged when adding oil. It will need more careful assembly with a new cam gear.
Center of crank to center of cam. 3.9367 to 3.9376
Dennis K Anderson