Grinding gears!
Posted: Fri Jan 20, 2017 4:00 pm
It?s a Denso-style pre-engaged starter with a 9-tooth pinion. The pinion was pretty beaten up, about half the tooth height ground off the front half of its length (which points to the back of the car). It replaced the original Lucas 9-tooth, and I've no reason to think my ring gear is anything other than the normal 110-tooth (1968 +2)
I sourced a replacement pinion with ancillary bits (spring, collar etc), (9-tooth and visually identical) and my friendly local auto electrician (lets call him Frank) fitted it to the starter for me. Frank was adamant my ring gear must be badly worn, loose or damaged somewhere, so I checked it carefully all the way around. No damage found, and the wear seemed reasonable (see attached photo).
Starter with new pinion was noisy from the outset, and now its grinding without turning the engine. The engine isn?t seized, feels 100% normal when you push it in gear.
I?m out of ideas, and I can?t summon the will to pull that starter again. It is seated perfectly and tightly bolted to the bellhousing, there?s zero play in the shaft, I?ve treble checked that my (many) pinions are the right (29.15mm) diameter, and I everyone I?ve shown this picture to agrees that the ring gear looks fine.
Why oh why won?t it turn that ring gear?