Harley 45 solo chewing up speedo drive gears

[Mutt]

Has anyone ever figured out WHY these gears keep getting chewed up? Many people that ride 45's have teh same problem, and no one I know has come up with a solution. A friends 50 model keeps chewing up gears. We installed both the plastic gear and the brass one. I checked the hub gear good the last time we had it off. I saw nothing that was a indicator that the steel drive gear was worn or chipped.
I tried machining a new groove in the cable housing, to allow the drive gear to center on the mating gear on the hub. That didn't help. Any suggestions?

Thanks
Mutt

[Paps]

OEM gears usually only wreck if the speedo cable hangs up. Some aftermarket ones go in to deep in to the brake backing plate. Some aftermarket brake backing plates have an incorrect angle on them.

[Mutt]

my buddy's bike has on original H-D backing plate, brake drum and original speedo and cable, but has trashed out both a plastic and a brass gear. Gear on drum I don't see any thing that stands out as being bad. I even machined a new groove in the drive housing, so the gear sat center on the gear on the drum. No change

Say, you ain't got a good right side 45 case with a 47 belly number on it you want to get off of would ya (or know someone that might)?

[T. Cotten]

I learned the hard way, Folks...

The quickest way to trash a 45" drive gear is to pull the rear wheel and drum off and on without pulling the drive first.

....Cotten

[1962300]

Same issue with my 1949 WL.
Plastic gear chewed up.
Brass gear in there now, but brass flakes appearing outside the rear area of thew wheel.
YAY!

[Architect]

The brass one lasted about 20 miles, and brass flakes everywhere!!!! Made a real mess. Replaced with a plastic gear and it is in there for over 100 miles doing the job. John Bordas rebuilt my original cable with a new "core", maybe that is making the difference. Also have a new aftermarket drum on the bike, maybe that is making a difference. I rebuilt an original drive with a new shaft from an aftermarket unit. Not sure what fixed the problem, but before this season I had no speedo for 4 years and I had tried all the tips. I agree with Cotten, when removing the rear wheel, take the speedo drive out of the drum before removing the wheel. I usually do it before the chain. It is real nice having it work though.