Clutch Hub (Shaft) Taper

[CaptMike]

I have two clutch hubs, one is a three stud with little ball bearings and a 5 stud with roller bearings. (Both are used, the original one was the 3 stud.) I was checking the fit tonight for a belt and looked to see if the clutch hub was touching the main shaft to sprocket shaft seal and noticed the 5 stud sits about 3/8" farther out than the 3 Stud. Checking hub info it looks like clutch hub fitment is from 1941 to 1984. So what gives? I can take some pictures if you'd like to see the difference. I was thinking about buying a New hub but I now I'm concerned about fit.

[RUBONE]

Why anyone bothers with that 5 stud crap escapes me! Got a clutch problem? Got a 5 stud? any more questions?
Robbie

[CaptMike]

I'm in total agreement on the 5 stud hubs. I got the 5 stud with a Primo Belt drive. It had to be for a pre-electric start bike (splined sprocket shaft). This one baffles me because my knowledge says it Should fit the taper of my '57 Transmission. There's got to be a logical answer.

[58flh]

I'm in total agreement on the 5 stud hubs. I got the 5 stud with a Primo Belt drive. It had to be for a pre-electric start bike (splined sprocket shaft). This one baffles me because my knowledge says it Should fit the taper of my '57 Transmission. There's got to be a logical answer.

Robbie hit it on the head! 3 is best! But getting back to your problem, check the keyway for damage!,A cracked keyway can cause your hub to expand when you tighten-up your hub-nut against it! REmember as you crank down on the nut it causes the hub to ride-up the taper & lock on the mainshaft. If you have a micrometer mic. the highest point of taper----then with a inside caliper measure your opening I.D. on the 5 spring-hub. They should br close but not over-(to tight) according to your mainshaft! You might be in for a bering change, if In right 2 bearing sizes were used on Pans!Mine has double row 36 balls if im correct--1 size sticks out in my head because i did 1 for a customer not long ago---(36 ball-bearings 7/32 outside dia. from 1948 to 1958 bikes- newer ones had 20 ballbearings ! You can use your hub by replacing to the bearing retainer & go to the 48 to 58 36 doublerow bearing set-up! ( I hope this helps you out Im going from memory--Did this job not that long ago, so its still pretty fresh up there!--GOOD-LUCK)58flh

[john HD]

mike,

page 2and 3 of this thread may be of help. Transmission Main shaft to Main drive gear oil Leak

if you are trying to use a "super nut" they do not play well with pre 65 hubs weather 3 or 5 stud.

john

[Bosheff]

H-D used ball bearings in a cage on the clutch hub up to about 1958 I believe. You can use the roller bearings on the same hub if you also change the cage. The ball bearings will leave a wear path on the bearing surface, so by going to the rollers you can extend the life of the hub for basically nothing. Five finger hubs a a waste of time and money....bosheff

[Hog54]

I have two clutch hubs, one is a three stud with little ball bearings and a 5 stud with roller bearings. (Both are used, the original one was the 3 stud.) I was checking the fit tonight for a belt and looked to see if the clutch hub was touching the main shaft to sprocket shaft seal and noticed the 5 stud sits about 3/8" farther out than the 3 Stud. Checking hub info it looks like clutch hub fitment is from 1941 to 1984. So what gives? I can take some pictures if you'd like to see the difference. I was thinking about buying a New hub but I now I'm concerned about fit.

If it sits father out it means the 3 stud is worn.I have been using a 5 stud for 15 years now and never had a problem.

[caschnd1]

If it sits father out it means the 3 stud is worn.I have been using a 5 stud for 15 years now and never had a problem.

I agree. The 5 stud hubs are not a problem. I've put >90K miles on my panhead with a 5 stud hub and it's never given me any grief.

-Craig

[CaptMike]

Ahhhhhhh... Seek and Ye Shall Find.

After a couple of hours digging in the Library here I found the Answer. The original clutch hub has a longer shoulder on the back of the hub (than the after market) and I suspect this is possibly why a Super Nut will not work (with the Pre-65 shafts). I've been going through my mind that the Friggin main shaft is going to Leak transmission oil (we old guys call "Dope"). I'm tempted to run the (yuck) 5 Stud/Finger hub that has the short shoulder and try a Supper Nut.

I need to post some "Project" progress pictures and might take a couple of clutch hub pictures. I'm sure the 5 stud hubs are fine, the extra studs are unnecessary in my opinion. You could do a 10 Stud (all with threads) it it blows your skirt up.

This link shows good pictures of the Sprocket Shaft too. Transmission Main shaft to Main drive gear oil Leak

[CaptMike]

Damn... To add Insult to Injury I just put an Dial Indicator on the Mainshaft and it has .008" of run-out. With the clutch hub hanging on it it makes the clutch hub move about a 1/8". (Didn't use the dial, only the right eye.) Sometimes I hate working on junk. I either tear the transmission back apart, look for another transmission or bolt it together as is (and the clutch hub is going to wobble like a Bitch.

[Hog54]

How would it wobble if its tightened on a tapered shaft?

[CaptMike]

How would it wobble if its tightened on a tapered shaft?

If the mainshaft is bent and you put a hub on it, now it wobbles worse. The .008" turns into about .125" on the outer edge of the clutch hub.

[steve_wood]

CaptMike:

The 0.008 play that you measured, do you mean that you can move the shaft forward/back by that amount? i.e. wiggle?

[RUBONE]

I believe he is talking radial movement!
Robbie

[CaptMike]

I believe he is talking radial movement!
Robbie

Already ordered a New Shaft. Not happy about it either. I have one trick I'm going to try before pulling the shaft (and it's not taking a BFMH to the shaft and destroying the bearing). I've been using a .01 mm indicator and on the clutch basket I'm getting a 120 x .01 x .0394" = .047" (holding the clutch basket and turning the hub). It looks like more when you see the amount of wobble.

At least I did get the rear brake assembled today.