Board index Flathead Power-Technical Questions, Answers, and Suggestions 45 Flatties 45 Racer transmission

45 Racer transmission

Post Tue Jan 03, 2012 12:21 am

Posts: 42
Location: seattle, washington
Hoping you all can bear with me here.

I am building a transmission for use in a 45" racer, i would like to use the 41 & later 3 bolt case and the early style or WR type clutch, i am aware H-D made a special 14T main drive gear for the 41 & later trans with the WR clutch, but these are either not available or to expensive.

I have a 1938 45" transmission, can i take the gear set from this trans and with machine work etc fit this into the 41 & later case, i see the length difference in the main and counter shafts as i have a 41 trans to compare with.

Looks like a sleeve could be made to fit the early style main drive gear case race into the 41 & later case.

Any help or experiance on this would be helpful to me and appreciated.

Post Tue Jan 03, 2012 6:36 am

Posts: 426
Location: Tucson Arizona

Post Tue Jan 03, 2012 10:56 pm

Posts: 42
Location: seattle, washington
Mr. Kurt, thanks i didnt even think to check for a re-manufactured gear as i thought on one would take the time to do the work.

Post Wed Jan 04, 2012 11:37 pm

Posts: 42
Location: seattle, washington
Kurt, i saw the gear on flatland mc site, what rollers will i need to install this and any other parts needed to fit this into my 41 gearbox.

Post Mon Jan 09, 2012 5:27 pm

Posts: 61
There's no practical way to use the early tranny parts in the 3 bolt case to run the narrow clutch. The parts from Kurt are all you need. They are excellent quality exact reproductions of the original WR tranny parts. It's been a couple of years since I used Kurt's parts, and at that time there were no instructions included. Below is a list of the things you need to do to use his parts and build a WR transmission.

1. You'll need 31 #9090 (old #2306-32) roller bearings.
2. The pushrod/thro-out bearing will need to be cut to 9 3/4" overall.
3. Before you install the race in the case you'll need to cut a 2.90" dia. x .090" deep relief on the clutch side of the case for the seal lip on the inside of the inner clutch disc to fit into.
4.You will also need to take .060" off the large end of the countershaft cluster gear.

Hope this helps.

Post Mon Jan 09, 2012 7:53 pm

Posts: 426
Location: Tucson Arizona

Thank you Ralph for stepping in.....I've been looking for days trying to figure out who sent me an e-mail with pix about the conversion. I've added the text from your original e-mail along with the pix you sent me.

Thanks!!!! :D

In the first one you can see the marks on the case where the inner clutch disc hit. The cut on the outside of the case needs to be 2.90' Dia. and be cut to a depth of .095'. The inner clutch disc will go into the case approx. .040' when installed on the clutch gear, but making the cut .095' will leave plenty of room for excessive end play on main shaft as the tranny wears, plus this will just get you down flush with your race.

Post Tue Jan 10, 2012 9:50 am

Posts: 767
Location: CA USA
When you cut down the throw out bearing push rod, use a ball end mill to cut a concave in the end of the push rod to match up with the clutch adjuster screw, then flame harden the finished product. Now you have a good usable copy of the original WR push rod.

Post Wed Jan 11, 2012 6:21 am

Posts: 141
Location: USA
Guys,thanks so much for sharing your experience,this is a perfect example of the generous sharing of information by builders,and business all working toward a common goal that benefits everybody.Still my favorite site on the entire web for getting the facts.Thanks all. :D :D

Post Sun Jan 15, 2012 10:13 pm

Posts: 42
Location: seattle, washington
Thanks everyone, i think i can do all this work and install these parts, but in the photos i did not see #4 to remove material from the counter gear, is this on the gear teeth end where the kicker teeth are?? please explain, i am assuming cause the WR copy gear is more narrow.

Post Mon Jan 16, 2012 8:27 am

Posts: 61
Kurt's parts are just like original WR parts. The WR transmission with the narrow clutch had a part #R2303-42 countershaft cluster gear that was .060" shorter than the standard cluster gear. The difference was in the large (left) end of the gear where the starter clutch engaged. The reason for this was because the clutch thrust bearing race #R2522-42 projected into the case further than it's #2522-41 counterpart.
I guess you could take the .060" off the right end and take .060" off one of the #2305-39 roller bearing end washers which are .180" thick, but I've never tried it this way before. Not sure what effect that would have on the alignment of the main and countershaft gears.

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