Pre 1951 pinion shafts

[camsaure]

Hi,
I am getting tired of the noise from the pinion shaft on my 1950 FL. I know the factory addressed the problem in the middle of 1951 with the press on pinion (the ones with the screw threads in the end of the shaft. I have not had much luck finding a NOS/OEM shaft or even a decent used one. If anyone knows a source it would be appreciated very much. Or what about the new aftermarket S&S shafts? Are they a tight fit like the 51 to 53 shafts or are they loose fit like the early ones?
Thanks Cam

[koanes]

Have you had the cam cover off to investigate the source of the noise you hear? If your gear is very loose on the shaft, try another gear. There is a lot of variance in the machining of both the shaft and the gear whether OEM or aftermarket. You could have a handful of shafts and gears and it would be unlikely to find a matching fit with any combination. The pressed on gears were a mistake and Harley went back to slip fit. My idea of a perfect fit is to have a gear that slides on with little or no pressure and no lash. Jim's machining had so much trouble trying to get it right, they opted to try to fit the large alignment spline and undersize the rest. Recently I've had the best luck with the shafts made by Eastern. If you find a gear that is a little snug, you can improve on that with a little fine lapping compound (600-800), just lightly tapping it on and pulling it back off. When you think its better but still tight, clean everything and try the fit with just a light oil. You'll be surprised at how fast the lapping goes and it is easy to get carried away.

[billpedalino]

Years and years ago when I worked in a high-volume motor shop I remember coming across several early 1950's pinion shafts with copper-flashed splines. I was later informed that this was done by the factory to build up the splines in an attempt to fix the pinion rattle problem. It makes some sense as in theory if the pinion gears were a slightly initial fit, the copper might wear and/or compress in use and offer a more acceptable fit. Apparently this fix didn't work too well and by 1955 the pinion shaft and associated gears were redesigned.

[camsaure]

Yes I had the cover off and the spline fit was quite sloppy. To verify I fitted the gear with Red Loctite and reassembled the gear case the next day The noise was gone, for about 25 miles when it returned. I then tried a new S&S gear that I had on hand and the fit was just as sloppy. That is why I wondered about the fit of S&S shaft/gears. Do you think that would work or would I be better off with an Eastern shaft? One more thing, Out of curiosity, what was the problem with the pressed on gear. By the way, thankyou very much for your expertise and reply. Cam

[Rubone]

I prefer to change the whole set-up to the '55-'57 type bearings and shaft, no more splines. ('54 was an oddball but later ones used the same right bearing as a Sportster.)

Out of curiosity, what was the problem with the pressed on gear.

It did not slide so if not perfectly spaced it chewed the bushing thrust face to bits.

[camsaure]

If I were to go that route I think the pinion bushing diameter is different. Am I correct to believe that the later 55-57 bushing fits the pinion cover? Thanks, Cam

[koanes]

The later bushing fits the hole and is easily installed. To make the conversion, you would need the shaft, bearings and cage, oil pump drive gear, spacer, pinion gear and nut. In 1954 they were still using the straight bearings on the sprocket shaft, which means your flywheel spacing is critical to make sure the feed hole in the shaft and bushing aligned. You will want to enlarge or oval the feed hole in the bushing to accommodate the shimmed flywheels in your 50. 55 and up have pressed on Timkens, so the flywheels are in a fixed position. If you cannot find a gear with a decent fit and have to replace the shaft, I would suggest buying the S&S shaft which will likely fit the S&S gear you already have.

[camsaure]

Thanks Koanes, I will be digging through all my parts today and see what I come up with. I doubt that I have many of the 55-57 parts, I know I am well supplied with rollers, cages etc, but don't recall having any decent shafts. ( the later shaft looks like the best route) I am pretty sure I would have overlooked the oil feed hole unless it is covered in the service bulletins. I don't recall ever reading anything on that. Pretty sure I will get an S&S shaft. I hate to tear down an otherwise great running engine but I cannot stand noise that could be remedied, it is almost embarrassing. On the bright side it looks to be a lot easier then when I was trying to quite down the gear noise in one of my VLs years ago. (sure do miss those VLs) It sure helps to hear from those whom have already "been there".
Thanks again, Cam