Different transmission cases

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MrBaging
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Joined: Wed Apr 28, 2004 7:56 am

Different transmission cases

#1

Post by MrBaging »

Description: Anyone out there that knows what case this could be?

Ok, got me a case in which i'm trying to put a later gear set... The gears i want to fit is from a 79 gearbox, and i'm well aware that i need to replace 4th gear/bearings and countershaft. BUT, the gearcase i got won't accept the big roller bearing (on kicker side), or gears, the hole is to small???
Anyone out there that knows what case this could be? Looking thru catalogs and such, and as far i can see, all gearboxes from 37 and up uses the same bearing.....
mbskeam
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Re: Different transmission cases

#2

Post by mbskeam »

hello,
Did you remove the steel bearing holder?It is a lite press fit in the case. If this is not it I'm sure others will be able to help you out. Pics help
mbskeam
49flguy
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Joined: Thu Nov 04, 2004 1:47 pm

Re: Different transmission cases

#3

Post by 49flguy »

You have a later model gear cluster that has a higher first gear than the old '36-up 4-speed. You can make the newer gears fit your box, but not without machining the case to accept the later mainshaft ball bearing housing. If you go this route, you will find that there will be very little meat left in the ball bearing housing for the bearing housing bearing retaining screws, but these aren't highly stressed components. Anyway, I updated my trans this way about 15 years ago and everything works fine. It's nice to have the taller first gear and you get less "clunk" going into second. If I recall correctly, you will have to have new collars machined for the later countershaft as well.

Hope this helps.

richard m.
MrBaging
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Joined: Wed Apr 28, 2004 7:56 am

Re: Different transmission cases

#4

Post by MrBaging »

Thanks guys! Ok, now i know why it don't fit

Mbskeam
Yep, bearing holder also removed....

richard m
Thanks, good explanation. Will probably go this way (same as you) if i only find a good machinist to enlarge the bearing hole.... Guess it's pretty critical to get the alignment perfect
As i regard that newer (79 1/2) case as scrap, could i remove the countershaft collars from that one, and put them in the early case or is it easier making new ones??

Lot of work just because i think those pancake tops are soooo ugly, but as you mentioned, they shift nice
49flguy
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Re: Different transmission cases

#5

Post by 49flguy »

MrBaging

Re countershaft collars: I'm not sure whether the newer collars will fit the old box. It's been a while since I've been into mine. Certainly worth checking before you get a new set made.
It has always seemed to me that first gear in the old 4-speed was too low unless you were riding a fully loaded dresser two-up in traffic or you were a motor cop looking for something that could be ridden really slowly without a lot of foot-paddling. Otherwise, it's nice to be able to pull away from a light and get a good way across the intersection before having to shift and this modification should do it for you.

regards,

richard m.
MrBaging
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Posts: 6
Joined: Wed Apr 28, 2004 7:56 am

Re: Different transmission cases

#6

Post by MrBaging »

Thanks, i'll look in to it. I'll see if i can get the old ones out without damage to the case.... could be of use to someone else perhaps...
Well, the bike is as thin and light as it get's, so i don't have to worry about moving a lot of mass at the redlights Rode it last year with the 79 1/2 gearbox, and as you say, the gearing is nice to ride. Ugly case though...
Thanks again, appreciate the inputs!!

Rgds /Stefan

Just wanted to let anyone interested know that the countershaft collars from the newer case fitted perfectly in the older case ;D

/Stefan
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