Clutch hub wobble...Need input

Post Reply
kevock1950
Posts: 52
Joined: Fri Jun 26, 2009 2:11 am
Bikes: 1950 Panhead chopper
1977 Shovelhead custom
Location: Pennsylvania

Clutch hub wobble...Need input

#1

Post by kevock1950 » Wed Aug 15, 2012 2:47 pm

Im having a clutch hub wobble with a relatively new BDL Competitor Clutch/hub/basket and I'm absolutely confounded at the possible cause(s). This clutch assembly is on a 4speed transmission with '65-69 tapered aftermarket mainshaft ( I think its RevTech...and before you call "junk," please read below).

When I originally installed this BDL clutch assembly, it had performed outstandingly, and resolved some of the clutch walking and shifting issues I had had with the stock clutch assembly.

Here's the current situation:

I disassembled the clutch assembly to replace a worn mainshaft seal due to running without a mainshaft bearing support bracket for several years. I R&R'd the seal with out any problems and installed a new mainshaft bearing support (with USA sealed bearing) to potentially eliminate wiping out the mainshaft seal again.

For shits & giggles, I measured the runout of the mainshaft with the mainshaft support bracket both ON and OFF...the runout was ~.004". As per Harley, this is within spec. So, mainshaft is good.

I then re-installed the clutch assembly (with freshly de-glazed clutch plates) and primary belt and torqued the mainshaft nut to 70 ftlbs. I then rotated the inner clutch club before putting the clutch plates back in and noticed a significant "wobble" in the whole clutch assembly. I then put the dial on the O.D. of the clutch basket and recored a .030" runout!!! Yikes. Thinking that the mainshaft was possibly tweaked, I pulled the assembly back off and checked the following:

1) runout of mainshaft is still in spec at ~.004"

2) installed BDL's inner clutch hub (with sealed bearing) and torqued to spec on mainshaft without the clutch basket. I did this twice...one with woodruff key installed in mainshaft, and once with out it. I measured runout of inner clutch hub at the sealed bearing race...it, too measured .004" in both situations

3) Once again, installed whole clutch assembly on mainshaft, with AND without woodruff key installed, and still recorded a .030" wobble!!!

4)Pulled off clutch assembly again and dressed the woodruff key a few thousandths so that it wouldnt sit as tall. Additionally, checked clutch hub keyway for burrs...no burrs.

5)Re-installed everything again, torqued to spec, and measured a .012" wobble at the O.D. of the clutch basket. I then fired the up the motor to see if there was any shifting or grabbing issues...there was. Pressure plate is not releasing square and the hub wobble is very noticeable

6)Pulled everything apart again. This time checked just the runout of clutch assembly while on the bench. Placing the dial on the O.D. of the clutch basket and giving it a spin, the runout is about ~.012"

7) Installed old 5 finger clutch hub onto mainshaft and torqued to spec. Checked the runout of this hub at the race area...runout is ~.004"

My questions:
1) Has anyone encountered a BDL inner clutch hub going south after original install?

2) Could this be a clutch hub sealed bearing issue?

3) Could this be a a woodruff key/clutch hub centering issue?

4) Could the clutch basket be tweaked?

Im at a loss here....

Tonight Im going to re-install the stock 5 finger clutch hub on this clutch basket and check for runout and wobble both on the bench and installed on the mainshaft

What am I missing here folks?

BDL's tech line is persistently busy. As far as Im concerned their tech is nonexistent.



1950Panhead
Posts: 1578
Joined: Wed Jul 07, 2010 4:28 am
Bikes: 1950Panhead
Location: USA

Re: Clutch hub wobble...Need input

#2

Post by 1950Panhead » Wed Aug 15, 2012 5:13 pm

BDL's tech line is persistently busy. As far as Im concerned their tech is nonexistent.
That's cause folks like you keep calling driveing them bananas.

The clutch should work with .012" runout.
Is the .012" on the inner hub bearing surface or on the back side?
Check both, original and BDL inner hub.
Check the mating surfaces inside hubs and shaft.

The outer basket can add inbalance from loose bearings.
Check runout on outer basket.
Jerry

kevock1950
Posts: 52
Joined: Fri Jun 26, 2009 2:11 am
Bikes: 1950 Panhead chopper
1977 Shovelhead custom
Location: Pennsylvania

Re: Clutch hub wobble...Need input

#3

Post by kevock1950 » Wed Aug 15, 2012 6:31 pm

The clutch should work with .012" runout.
The clutch does work, but because of the hub/basket wobble, the pressure plate isnt releasing squarely causing a 1st gear "thud" and extreme difficulty finding neutral. The whole clutch assembly, when clutch is engaged, shows a noticable wobble. That was NOT present before disassembly for R&R of mainshaft seal.
Is the .012" on the inner hub bearing surface or on the back side?
The .012" runout is measured on the O.D. of the clutch basket, NOT on the the inner hub bearing surface. Without somehow bolting the basket to a lathe, I have no way to properly spec the inner hub bearing surface for runout...and I dont have access to a lathe or mill turn-table. Got any shade-tree DIY ideas for me here?
Check both, original and BDL inner hub.
Check the mating surfaces inside hubs and shaft.
I did, as noted above. Both BDL inner hub (measured at O.D. of the sealed bearing race) and original 5 finger clutch hub (measured at roller bearing race O.D.) is .004".
The outer basket can add inbalance from loose bearings.
Check runout on outer basket.
Also, as noted in previous post, when inner hub is bolted to basket, and either torqued to spec on the mainshaft or spun on the bench (as an assembly), basket O.D. runout is ~.012".

The BDL clutch hub sealed bearing is NOT loose or cracked and doesnt feel "notched." Its fit in the clutch basket is perfect...no wonkiness or wobble. The bearing race surfaces of the basket and the sealed bearing are perfect...no scoring, galling or hot spots.

Is there a chance that the inner hub taper isnt cocentric? If so, why would simply disassembling it cause it to lose cocentricity??? Would help if BDL answered its tech calls and email.

Im stumped.....and would be mighty pissed off if I had to spend $250 on replacing the inner hub and race, simply because I disassembled it.

john HD
Moderator
Posts: 3669
Joined: Sat Aug 20, 2005 7:24 pm
Bikes: '42 WLA X 2, '55FL, '93 Ultra Classic, '91 Fatboy, '97 883, '71 Suzuki Duster 125, '83 GPz 750.

Re: Clutch hub wobble...Need input

#4

Post by john HD » Wed Aug 15, 2012 10:20 pm

kev,

you might have raised a burr on either the main shaft or the basket.

what kind of key are you trying to use?

one thing you may want to try is to loosely assemble the hub on the shaft without the key, put the tranny in gear so the shaft won't spin. then with some fine valve lapping compound on the taper rotate the hub assembly until each part of the taper has a smooth surface. this will mate the parts and make the taper match as much is possible.

clean, add the key and see if it is any better....

john

kevock1950
Posts: 52
Joined: Fri Jun 26, 2009 2:11 am
Bikes: 1950 Panhead chopper
1977 Shovelhead custom
Location: Pennsylvania

Re: Clutch hub wobble...Need input

#5

Post by kevock1950 » Wed Aug 15, 2012 10:30 pm

you might have raised a burr on either the main shaft or the basket.
what kind of key are you trying to use?
I had a minor burr in the keyway of the clutch hub...I filed it clean and its fine. I also dressed the mainshaft woodruff key (half-moon type key) to be sure it was burr-free. I also filed it a few thousandths thinking it was sitting too tall, hanging up the hub...but, its not. Changing the key height did nothing to the overall clutch assembly runout...theres still a wobble.
one thing you may want to try is to loosely assemble the hub on the shaft without the key, put the tranny in gear so the shaft won't spin. then with some fine valve lapping compound on the taper rotate the hub assembly until each part of the taper has a smooth surface. this will mate the parts and make the taper match as much is possible.

clean, add the key and see if it is any better....
Great idea... I will try it.

Thanks.

john HD
Moderator
Posts: 3669
Joined: Sat Aug 20, 2005 7:24 pm
Bikes: '42 WLA X 2, '55FL, '93 Ultra Classic, '91 Fatboy, '97 883, '71 Suzuki Duster 125, '83 GPz 750.

Re: Clutch hub wobble...Need input

#6

Post by john HD » Wed Aug 15, 2012 11:51 pm

kev,

good, let us know how that turns out...

as for the key, stock ones are not the full half moon type. they have the ends clipped off at each end.

perhaps your key is binding in the keyway.

lapp it to a good match and see how it fits.

john

1950Panhead
Posts: 1578
Joined: Wed Jul 07, 2010 4:28 am
Bikes: 1950Panhead
Location: USA

Re: Clutch hub wobble...Need input

#7

Post by 1950Panhead » Thu Aug 16, 2012 2:00 am

The .012" runout is measured on the O.D. of the clutch basket, NOT on the the inner hub bearing surface. Without somehow bolting the basket to a lathe, I have no way to properly spec the inner hub bearing surface for runout...and I dont have access to a lathe or mill turn-table. Got any shade-tree DIY ideas for me here?
If this was my bike I want to know runout on inner hub.
Torque inner hub to mainshaft. I have a vise (many vices), I have a dial gauge, set vise and dial gauge on bearing surface, spin hub, note runout. Move gauge to back, spin hub, note runout.
If gauge reads high twice (bearing and back) hub it tilted or bent shaft.
If back is hign on bearing but flat on back that means bearing surface is not concentric.
If both read flat add outer basket and repeat.
Jerry

58flh
Posts: 3338
Joined: Sat Jun 26, 2010 1:54 pm
Bikes: 1958flh 1969sporty,had a knuckle but sold back to original owner
Location: NEW JERSEY

Re: Clutch hub wobble...Need input

#8

Post by 58flh » Thu Aug 16, 2012 12:15 pm

You had said that you removed the plates!--Putting them back in I doubdt you put in exact sequence as removal!--Therefore if all your runouts are in spec, Maybe you need to watch the disengagement & engagement while kneeling down --Most likely you will see it release unevenly!--So you might just need an ADJ. on 1 of the nuts to establish a even as possible opertion of all the plates & friction-discs!--my 2---RICHIE

Post Reply

Return to “Clutch”