Board index Flathead Power-Technical Questions, Answers, and Suggestions 45 Flatties 1946 Rear Brake

1946 Rear Brake

Moderators: Curt!, Pa

Post Tue Oct 27, 2015 6:07 am

Posts: 100
Good morning all,

So I had been having an issue with my rear wheel/brake, I decided to take the wheel off the bike and give it an inspection. Glad I did though not happy with what I found. The five bolts holding the drum to the wheel hub are all gone!??!?! Lesson learned, they will become part of the pre-ride inspection. But now I need to deal with the consequences and I have multiple questions:

1- The dowel pins are loose and rounded over, looking bad in general. I see replacements online, how do the get removed and replaced?
2- The holes in the wheel hub have been slightly enlarged from the dowel pins banging into them once the wheel was loose. Every other hole still appears to be OK. During re-installation, would you put the pins or the bolts in the slightly "egg" shaped holes? Or is there an alternate method?
3- Please refer to picture below, the speedometer gear got chewed up in the center by the sleeve/spacer inside the drum. Does it need to be replaced? If so I see the gear for sale online, how do you change just the gear?

IMG_0725.JPG


Thanks in advance, let the schooling begin.
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Post Tue Oct 27, 2015 8:03 am
Pa Site Admin

Posts: 5772
Location: Ohio USA

Real sorry to hear of your misfortune. There are oversize replacement hub screws 4026-35S, if your threads are screwed up. But you will need to re-tap your drum to use the oversize ones. If you can get away with using standard 4026-35 screws, use them. I had nos military packaged 4026-35S ones but got rid of them. Tom has the dowels in nos http://www.tomsnosparts.com/cgi-bin/dbs ... er=4035-37. As far as the holes the dowels fit into. I don't see aw way to make them right again. My thought would be to replace the dowels an load the drum in the direction of engine load, tighten down the new hub screws and ride it. I've replaced one speedometer drive gear. I do not remember how I removed it though. I do remember how I installed the new one. I heated it in the Ole Ladies over to 300 degrees F. It drop down on easily. I believe I also staked it. I am pretty sure George from Germany, a long time member on this forum, has done them as well. I think he posted ho he did it. Do some keyword searches or look up George in the members list under G and ask him.

Post Tue Oct 27, 2015 8:34 am

Posts: 100
Pa wrote:
Real sorry to hear of your misfortune. There are oversize replacement hub screws 4026-35S, if your threads are screwed up. But you will need to re-tap your drum to use the oversize ones. If you can get away with using standard 4026-35 screws, use them. I had nos military packaged 4026-35S ones but got rid of them. Tom has the dowels in nos http://www.tomsnosparts.com/cgi-bin/dbs ... er=4035-37. As far as the holes the dowels fit into. I don't see aw way to make them right again. My thought would be to replace the dowels an load the drum in the direction of engine load, tighten down the new hub screws and ride it. I've replaced one speedometer drive gear. I do not remember how I removed it though. I do remember how I installed the new one. I heated it in the Ole Ladies over to 300 degrees F. It drop down on easily. I believe I also staked it. I am pretty sure George from Germany, a long time member on this forum, has done them as well. I think he posted ho he did it. Do some keyword searches or look up George in the members list under G and ask him.


Pa, thanks for the reply. The threads for the bolts are good, the bolts just worked themselves out.

Follow up question on dowels, how do they come out and go in? Press? Peening?

Follow up question on the gear, does it look like it NEEDS to be replaced. The area that was worn down does not appear to serves a purpose? The outside for the speedometer looks OK. What do you think? In the meantime I will look up George.

Post Tue Oct 27, 2015 11:56 am
Pa Site Admin

Posts: 5772
Location: Ohio USA

I've never removed the dowels but I assume they are a light press fit. That link in my previous post at Toms NOS Parts shows a very clear pic of an nos one.

Post Tue Oct 27, 2015 12:32 pm

Posts: 306
Hi Arch,

I had similar issue with the bolts running out. I learned then that when using the harley tool, you need to get an extention pipe as long as possible and just torque the bastards down to the point just before breaking.. Later ( after a bolt broke) I learned its smarter to apply just the tiniest bit of locktite to keep them in place and torque them down good but not go berzerk on them..

Dowelpins: No clue what to do, pins can be replaced. I would use the still round holes to hold the pins. and use the oval ones with the bolts, as they are only to keep the drum tight to the hubsideways, while the pins should restrain it from moving forward or backward

Post Tue Oct 27, 2015 3:24 pm

Posts: 100
Samsup wrote:
Hi Arch,

I had similar issue with the bolts running out. I learned then that when using the harley tool, you need to get an extention pipe as long as possible and just torque the bastards down to the point just before breaking.. Later ( after a bolt broke) I learned its smarter to apply just the tiniest bit of locktite to keep them in place and torque them down good but not go berzerk on them..

Dowelpins: No clue what to do, pins can be replaced. I would use the still round holes to hold the pins. and use the oval ones with the bolts, as they are only to keep the drum tight to the hubsideways, while the pins should restrain it from moving forward or backward



That all sounds reasonable, thanks.

Anyone have an opinion on my NEED to replace the speedometer gear? If you think yes, I have not been able to find the thread from another member, though I did PM him. I anybody has any thoughts it would be appreciated.

Post Tue Oct 27, 2015 3:47 pm

Posts: 306
Architect wrote:
Samsup wrote:
Hi Arch,

I had similar issue with the bolts running out. I learned then that when using the harley tool, you need to get an extention pipe as long as possible and just torque the bastards down to the point just before breaking.. Later ( after a bolt broke) I learned its smarter to apply just the tiniest bit of locktite to keep them in place and torque them down good but not go berzerk on them..

Dowelpins: No clue what to do, pins can be replaced. I would use the still round holes to hold the pins. and use the oval ones with the bolts, as they are only to keep the drum tight to the hubsideways, while the pins should restrain it from moving forward or backward



That all sounds reasonable, thanks.

Anyone have an opinion on my NEED to replace the speedometer gear? If you think yes, I have not been able to find the thread from another member, though I did PM him. I anybody has any thoughts it would be appreciated.



isnt it your drum itself that has been eaten? I think the gear sits on the drum shaft.. Usually the speedoes on WLs dont work anyway so why bother replacing the gear... If you really insist on doing it I think bolting the drum down to a table or so and then using a puller on the ringgear should do the trick. Only other way I see is to carefully cut it open with a tiny disccutterthingie and hope it pops off

Post Tue Oct 27, 2015 4:56 pm

Posts: 307
Location: Ohio
That gear looks fine to me. The question is, is it where it’s supposed to be. First check how true it runs around the I.D. of the brake drum. Then check how square the face of it runs to the axle. If both of those are within .020, I’d say you’re good to go.

Post Tue Oct 27, 2015 5:11 pm

Posts: 307
Location: Ohio
That thing is pretty chewed up. I can’t tell you if it’s worth the trouble to replace it though. This one is 70 years old and still in pretty good shape.

Image

Post Mon Nov 02, 2015 11:27 am

Posts: 306
To me it looks like a portion of the drum is eaten away, and the ringgear is just around it..

Post Mon Nov 02, 2015 12:29 pm

Posts: 100
First off, glad to see the new and improved Forum back up and running.

Yes it is the drum not the gear that is chewed up, agree with all of your comments.

My plan is to keep the drum, trying to do some refurbishing work. Drove out the old dowel pins, but my press is not strong enough to install the new ones. Going to my local machine shop this afternoon to see if his press can make it happen.

Going to ask him about welding the lip back and then running it through a lathe to re-turn the inside. Not sure how much I really need the area of material, the sleeve does not seem to need it.

Post Thu Apr 28, 2016 11:49 am

Posts: 100
Just for closure, all the dowels pins were drilled then pressed out. New pins installed with a press, my 6 ton unit was not enough brought it to a machine shop. I left the drum alone, the internal spacer does not even seem to come into contact with the drum in this area so we are giving it a go as is.

Wheel is back together and have done about 30 miles on the bike this season, no issues all seems well.

Post Thu Apr 28, 2016 4:05 pm
Pa Site Admin

Posts: 5772
Location: Ohio USA

Geeze....I forgot about that wheel issue. Glad to hear you got it all worked out.


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