Split Collar Altenator Fix

Vanmor · #1 9th July 2012

Hi Folks. You ride a late model Iron Head or an early EVO right ? Your bike has stopped recharging the battery right ? You've replaced a few things but that didn't work. Now you have to remove the primary cover. Is this what you found ?

Yep, broken or ground up magnets.

After you remove the clutch assembly, I bet your stator looks like this.

Pretty nasty stuff huh ?

As you can see, these bikes share a similar bottom end with the altenator integrated with the clutch assembly. When the clutch assembly starts to get a bit of wobble due to wear on the splines, the magnets mounted on back of the clutch come in contact with the stator. The results are what you see here.

A common fix is to get a thicker transmission trap door with a double row bearing and a clutch with a sealed ring around the magnets. This is an expensive fix and I've read that the problem will return eventually.

A cheap and effective fix is to place a split collar on the shaft behind the clutch assembly. I've read that it works very well.

I'm going to give this a try and if you follow along, we'll see if it's a viable repair.

Vanmor · #2 10th July 2012

Didn't make it to the machine shop today. Had a couple of doctor's appointments and just ran out of time.

In the mean time, a look at what causes the problem can't hurt.

The clutch assembly rides on the splined input shaft (clutch gear) of the transmission. However, there is an area on the shaft that is recessed. As the picture shows, there is a bit of a groove in the splines of the clutch hub. The area above the groove is sitting over the recessed area providing no contact with the shaft. So there is only about 75% or less of contact area on the shaft. Even though the splines are not worn that bad, a wobble starts to occur.

The addition of the split collar in the recessed area allows the clutch assembly to have more support. This helps to reduce or eliminate the wobble. From what I've read, the fit needs to an "interference fit". Meaning that the clutch hub needs to slide up on the split collar but be tight. I figure a light tap with a rubber mallet or a hammer with a piece of wood will give just enough force to push the clutch assembly on the shaft and over the split collar.

By the way, you DO NOT have to dissasemble the clutch. Just remove the clip and washer. However, you will need to remove the front engine sprocket, chain, and clutch assembly all at one time. Check your manual for procedure.

Vanmor · #3 11th July 2012

Today's task was to visit all the old mom and pop machine shops I knew about years ago. They are just about all gone or under new management. So that means I'll have to find a machine shop that will take on a small project like mine. Nice.

Anyway.....

During the last few months, I dug through all my old junk and looked at the steel pipe hardware places had on hand. I couldn't find anything that was suitable. Either the outside (O.D.) was wrong or the inside diameter (I.D.) was incorrect. I could use solid stock but I didn't want to buy the minimum. (I know, I'm cheap !)

Then it hit me....

I had this steel pipe left over from an old springer front end I cut down. As with most springers, there are two big tubes in the rear and two small ones up front. Turns out the two big tubes on the left were just what I needed size wise.

Problem is, they still have the chrome on them. A lot of machine shops won't machine something that has chrome on it. I've tried to acid strip it but the chrome hangs in there. Guess they used a tougher chrome back in the 60's.

I'd really like to use this steel because it looks to be seamleass, the size is close to correct, and it's really hard. I've used it to drive out steel bushings and it hasn't "mushroomed" a bit.

It's just something to work around. Standby......

kd460 · #4 11th July 2012

Finally someone posting a write up. And THANK YOU FOR DOING THIS!!!!!

Ever consider using shim stock or feeler gauge material and of course trimming to fit? Bending, etc? Not sure if it would work, just thinking out loud.

Watching this thread closely, and have my finger on the save button....KD

benton · #5 11th July 2012

I find a bunch of bushings on Amazon that may give you a starting point (search Industrial & Scientific). Koch brand especially has brass and nylon ones. For example:

Bunting Bearings Cast Bronze C93200 SAE 660 Plain Sleeve Bearings: Amazon.com: Industrial & Scientific

Vanmor · #6 12th July 2012

kd460,

I've thought about shim stock. The only problem I see with that is most shim stock seems a bit soft. Actually, I've aways made my shims from beer or soda cans. I've used old feeler gauges when I had too. (At least you know how thick the material is !)

What about exhaust pipe sleeves ? Some of the old Japanese machines had a split flanged collar that went around the exhaust pipe under the retainer ring bolted to the head.

Oh hey, maybe even some old rod or crank bearings.

Hmm..... I guess one's imagination is the limit as to what you can do.

benton,

Those sleeve bearings made me think of wheel spacers. You can get them at a local shop or online. They're pretty cheap and are made of hard stuff. Don't know if you can get them at 1 1/4" OD though. Thanks for the link. Those plain bearings are a possibility.

The reason I want to machine the tubing is control. If the dimensions can be controlled, there is less chance for further problems. I could cobble something up and make it work. Then the question would be for how long. We already see what a "wobbling" clutch assembly can do the charging system.

Now that I think about it, every type of clutch setup I've seen like this has some wobble to it. My old Shovel head was like that and my 56' Triumph Bobber was too. So it's really important that we calm down the wobble as much as possible. I'm looking for a permanent fix. Or a fix that will last as long as the clutch hub itself.

benton · #7 12th July 2012

Here ya go! In brass and aluminum. These have as close to the right ID (1-3/16) and OD (1-1/4) as you're going to get, just tell us how to cut and use them!

Aluminum 6061-T6 Seamless Round Tubing, WW-T 700/6, 1.18" ID, 1.25" OD, 0.035" Wall, 12" Length: Amazon.com: Industrial & Scientific

kd460 · #8 12th July 2012

I'm loving every minute of this discussion! Lots of possibilities.

Yes feeler gauge is exactly what I was thinking as well. Yes it is soft. But, is it softer than brass or aluminum?

I have a couple of those split adapters/spacers for exhaust pipes leftover from a previous motorcycle project. I guess I need to dig them out and start measuring thickness.

Do you guys think a "standard size" for the collar will work across the board for multiple bikes (with our typical clutch setup) or will each setup need a different thickness?

I would assume each basket would be different when it comes to washer thickness (bearing shim/spacers). But that should be easy enough to measure and purchase from the link Benton provided.

My thinking is, make up multiple split collars and make them available to other xl forum members. I'd be interested in a set or two.

I would also be interested in helping with the "development/machine shop costs" if needed. Not sure how much demand there is, but, if enough could be made, they could be sold to help offset the "development/machine shop cost" to produce them.

Currently, I recently replaced my clutch basket with the sealed v-twin unit. The new basket took out alot of the slop I had. I did not have the mess you had. Mine was not hitting and my magnets were still intact. I caught it in time.

That being said, I would pull my primary this winter just to put in the split collar and the spacer to take up any of the remaining slop.

EDIT: "Now that I think about it, every type of clutch setup I've seen like this has some wobble to it. My old Shovel head was like that and my 56' Triumph Bobber was too. So it's really important that we calm down the wobble as much as possible. I'm looking for a permanent fix. Or a fix that will last as long as the clutch hub itself."

Yes, I have noticed that also with some other bikes as well, BUT, the issue here is the clearance or gap between the magnets and the stator. That gap is small, so as thing wear like trap door bearing or splines, (and get loose or sloppy) the magnets are kissing the stator. Can't remember what the actual gap is (have it written down somewhere) but it is less than forgiving....

Again guys, just thinking out loud. Thanks, KD

Vanmor · #9 12th July 2012

benton,

I would use a pipe cutter or a cut off wheel on a "dremel motor". The width of the split collar should be only 3/8" inch. Then sand or file the top edges off so they don't hang on the clutch hub when you push the "clutch pack" back on. Before you sand or file them, cut the collar in half. Make sure your cut is good and square. A dab of grease should hold the split collar on while the clutch assembly is pushed back onto the shaft.

Don't really know about the materials though. That aluminum is going to be soft and may wear a bit. The brass may be better, but it too can run soft depending on the make up of the brass. I'm a little concerned about the dimensions too. I measured an I.D. of 1.191" inches and an O.D. of 1.253" inches. That's about 0.060" inch thickness. The tubing listed seems a tad shy on the numbers, but I'm not going to say they won't work. You get 12" inches of tubing to work with, I like that. The only way to really know is to try it out.

kd,

I think the dimensions on all the bikes would be pretty close. Seeing how bad mine is, I imagine the thickness of the split collar would be at the max. This is where I think brass would be a good choice. It's strong but soft enough to let a clutch assembly to be pushed up on it. Heck, the cam cover has brass bushings in it for the end of the cams. But they sure are thick looking.

Thanks for asking about helping out on the development cost. I'll have as many made that I have material for. If they work well, you and anybody else can have them for what they cost to machine. I found out an old friend of mine my be operating a small operation out of the back of his home ! If this is true, it won't cost me anything to machine. I thought about developing a kit with replacement gaskets and o-rings for the primary cover, but I'll just have to see how it goes.

I really like the idea of the steel ring covering the magnets. I have some replacement magnets, but I'll have to "glue" them back in. I hear you can shave the magnets down a few thousands and or add the stainless steel ring. This gets into more machine work though. I was thinking about getting a new primary front engine sprocket too.

This is fun and I like the input so far. It really makes you think of ways to keep these older bikes on the road. I hate the idea that these engines get retired or junked because of a small design flaw that can be easily fixed.

benton · #10 12th July 2012

There's some steel tubing too on Amazon. Aluminum and brass will thermally expand more than the steel, so they'll both bite into the splines when warm. Aluminum against steel has corrosion potential and brass against steel is somewhat better for this. Once the tube is split there will be a gap so the half tubes have space to bend to meet the inner shaft. Maybe a brake hone could be used to increase the inner diameter. My transmission's apart right now waiting on gears and a new clutch hub, so maybe I'll give it a go.