Replacing Speedo Drive; Help

[RichardL]

All,

When doing the big restoration that started in 2003 and, basically, completed in 2006, I discovered that the speedo drive shaft had a damaged tooth. I bought a replacement shaft on eBay around that time, but have deferred installing it until now, because I'm ready to install a speedometer. Considering the way the thing is designed, I figured it would be a fairly easy out and back in. HA! FOOL! Out was OK. Trying to get it back in is a whole other issue. While in its removable brass bush, it slides in and stops when it gets up against the gear on the lay shaft. I tried rotating the lay shaft via the rear wheel while tapping on the end of the bush, no real progress. Tried sliding the shaft in without the bush and could not find the end bush beyond the lay-shaft gear.


So, can anyone out there offer tips for this. Might it be that I just need to keep at the approaches I've already tried unitl one of them works? Is there some other trick that does not require removing the gerabox outer cover? Am I now committed to removing the outer cover?

Thanks, in advance, for your suggestions.

Richard L.

[RichardL]

Manosound,

For lack of anyone with more experience chiming in, let me offer a few things you might try:

1. Grind just a bit more chamfer on the ends of the driven gear teeth and file between them a little bit to ease it's way into the drive gear.
2. Grind a bit of chamfer on the end that goes into the bush beyond the drive gear so as to ease its entry therein.
3. Check to see if the new drive gear has the same O.D. as the original on the end that goes into the bush beyond the drive gear. If not, maybe, chuck it up in a drill motor and hold a file against is to slightly reduce the O.D.
4. Don't be stupid and forget that the lay shaft turns when in neutral, making it easy to turn the rear wheel and get the teeth in line.
5. While tapping the long bush home, keep turning the rear wheel in the forward direction (of course this will be harder in fourth gear than neutral, if you happen to forget).
6. When close to home, slide in the keeper screw and tap the bush in or out, as necessary, while pushing on the keeper screw so that it can find the relief in the bush.

I don't know if any of these will work, but good luck.

 

Richard L.

[RichardL]

Richard L.,

As usual, you are not totally definitive in your suggestions, so I tried everything you said except, of course, remembering to do the work while in neutral. At least I removed the spark plugs (today, not during last night's attempt). Anyway, I finally got it in. I don't know which of your suggestions actually helped, maybe all of them, maybe none of them, but it's back in. The one thing that has me worried is if I damaged the speedo drive gear on the end of the lay shaft while klutzing around last night while working in gear. I guess I'll buy one if I see it come around, just to hedge my bets when the gearbox must ultimately be opened for work.

Thanks, I think, for your help.
 
     

Manosound