Pinion shaft oil modification

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montuckymatt
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Pinion shaft oil modification

#1

Post by montuckymatt »

Heres an old tech tip from a now defunct shop. Thought I should share it as it might be useful to the board
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RooDog
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Re: Pinion shaft oil modification

#2

Post by RooDog »

The 360 Degree groove is the way I did my '68 Shovelhead.....
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Andygears
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Re: Pinion shaft oil modification

#3

Post by Andygears »

Or you could cut an ID groove in the bushing before it is pressed in. They, the aftermarket, used to sell them as a improvement back in the day.

My Panhead had one that was put in years ago, did work to oil rods, but too much for the breather, constantly puked out the primary breather. Yanked it ( among other things) and motor breathes correctly now.

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kitabel
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Re: Pinion shaft oil modification

#4

Post by kitabel »

H-D could have done all of these things at no expense, but did not.
Why are they needed now?
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Re: Pinion shaft oil modification

#5

Post by Andygears »

kitabel wrote: Sun Apr 25, 2021 1:27 am H-D could have done all of these things at no expense, but did not.
Why are they needed now?
Speaking of oiling/breathing improvements, what happened to the guy with all the pipes from his pan covers?

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RUBONE
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Re: Pinion shaft oil modification

#6

Post by RUBONE »

kitabel wrote: Sun Apr 25, 2021 1:27 am H-D could have done all of these things at no expense, but did not.
Why are they needed now?
They actually did do the full circumference pinion shaft groove on their racers. But those were not intended for breather efficiency or long distance use.
montuckymatt
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Re: Pinion shaft oil modification

#7

Post by montuckymatt »

I wanted some internal improvements as I ride my 37 almost everyday at high speed (most posted speed limits are 70-80mph here in Montana). I dont think the factory intended these motors to run at 65-70mph for 600 miles in a day. I did that with mine last summer. It ran like a champ.I put 250 miles on it last month in a day averaging 60mph. With the 4 vane oiler and modified oiling, my bike seems to run cooler. My last 37 had stock internals and cooked my nutz. So far, seems like time/money well spent.
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Re: Pinion shaft oil modification

#8

Post by Pascal »

My experience is with 45 Flatheads only..
You don't need to 'fullflow' these little motors.
One of my WLA's had a 360 groove in the shaft and it kept over-oilong.
Replaced it with an original pinion shaft, and all is well now.
She's very happy at 50-55 all day long
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Re: Pinion shaft oil modification

#9

Post by RUBONE »

Pascal wrote: Sun Apr 25, 2021 7:58 pm My experience is with 45 Flatheads only..
You don't need to 'fullflow' these little motors.
One of my WLA's had a 360 groove in the shaft and it kept over-oilong.
Replaced it with an original pinion shaft, and all is well now.
She's very happy at 50-55 all day long
Big twins are the same Pascal. My '44 UL has been on the original oiling system since I built it in the late '70s, and has pulled a sidecar at 55-60 for hours at a time two up with baggage, at long distances and lots of elevation changes. It has never had an issue.
Hot Rodding is another whole subject.

Here on top of Lizard Head Pass Colorado in 1990, AMCA D-J run. 10,246 Ft high, the day before we went over Red Mountain Pass at 11,018. This was carrying my wife and all our gear, and we rode there from home.
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