Changing 4-speed mainshaft seal

Any way to do this without the $250 Jim's tool?

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Mongrel505558
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Changing 4-speed mainshaft seal

#1

Post by Mongrel505558 »

I recently blew up the mainshaft bearing on my panhead gearbox. I have another box that's been sitting around for years. It's in good shape - at least by outward appearance - I will investigate further. The mainshaft is the right length for my bike. I'm springing for a shifting fork alignment tool because I want to take the shifter top off and get at least a look inside. I'm assuming the mainshaft seal is shot because they usually are. Is there a way to change it without spending 220-250 bucks on a tool I will only use once?
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Re: Changing 4-speed mainshaft seal

#2

Post by RooDog »

1) I have never had a need for the shift fork tool in over 50 years of doing this $hit. It just takes patience and a steady hand to check out the spacing. I have had access to the tool, but actually found it to not be much help. I would rather spend the money on beer and hard parts for my scooters.

2) Again why buy a tool when you can punch a coupla holes with an "ice pick", use sheet metal screws or a slide hammer to pop out the old seal, and then tap the new one back in place. You are not gonna reuse the old seal, so there is no need to be gentle with it.

I don't even know why the MoCo came up with that fancy puller in the first place.....
....RooDog....
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Re: Changing 4-speed mainshaft seal

#3

Post by RUBONE »

The top tool works great and makes it a 30 second job to check spacing if you use it right. I made Go/no go gauges from old spokes to check spacing, and keep them with the tool. Luckily most of my tools were acquired decades ago and from old dealers so they were pretty cheap. If time is all you have then do it the hard way (when you work against flat rate all the tools make sense!). The seal tool isn't needed, sheetmetal screws, a slide hammer, a piece of PVC pipe and it is all good. And if the box is apart you don't even need any of those.
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Re: Changing 4-speed mainshaft seal

#4

Post by Buddhahoodvatoloco »

..........50 years of doing this $hit. :lol: :lol: :lol: :lol: :lol: :lol: :lol:



b][/b]
RooDog wrote: Wed Jul 01, 2020 6:45 pm 1) I have never had a need for the shift fork tool in over 50 years of doing this $hit. It just takes patience and a steady hand to check out the spacing. I have had access to the tool, but actually found it to not be much help. I would rather spend the money on beer and hard parts for my scooters.

2) Again why buy a tool when you can punch a coupla holes with an "ice pick", use sheet metal screws or a slide hammer to pop out the old seal, and then tap the new one back in place. You are not gonna reuse the old seal, so there is no need to be gentle with it.

I don't even know why the MoCo came up with that fancy puller in the first place.....
....RooDog....
Mongrel505558
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Re: Changing 4-speed mainshaft seal

#5

Post by Mongrel505558 »

RooDog wrote: Wed Jul 01, 2020 6:45 pm 1) I have never had a need for the shift fork tool in over 50 years of doing this $hit. It just takes patience and a steady hand to check out the spacing. I have had access to the tool, but actually found it to not be much help. I would rather spend the money on beer and hard parts for my scooters.

2) Again why buy a tool when you can punch a coupla holes with an "ice pick", use sheet metal screws or a slide hammer to pop out the old seal, and then tap the new one back in place. You are not gonna reuse the old seal, so there is no need to be gentle with it.

I don't even know why the MoCo came up with that fancy puller in the first place.....
....RooDog....
That's the answer I was hoping for.
Mongrel505558
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Re: Changing 4-speed mainshaft seal

#6

Post by Mongrel505558 »

RUBONE wrote: Wed Jul 01, 2020 6:58 pm The top tool works great and makes it a 30 second job to check spacing if you use it right. I made Go/no go gauges from old spokes to check spacing, and keep them with the tool. Luckily most of my tools were acquired decades ago and from old dealers so they were pretty cheap. If time is all you have then do it the hard way (when you work against flat rate all the tools make sense!). The seal tool isn't needed, sheetmetal screws, a slide hammer, a piece of PVC pipe and it is all good. And if the box is apart you don't even need any of those.
Nice collection of tools there. Having a knucklehead on your bench is pretty cool,too!
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Re: Changing 4-speed mainshaft seal

#7

Post by Raytag »

What are these two for ?

Ray
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Re: Changing 4-speed mainshaft seal

#8

Post by RUBONE »

Riveting brake drums, top one is BT, bottom is 45.
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