swing arm freeplay

[sarc]

my swingarm feels tight but slides left and right about1/8". is it ok, should I block it with a washer?

thanks

[ringadingh]

I would definitely shim it with washers if its moving around that much. That much play would affect your steering especially through the corners and cause the bike to wander.

[sonny]

A question from the mechanically declined. How would a swing arm get in that condition?
Thanks for your time.

[damark115]

There are seals on each side that also act as spacers, Poor design. Sounds like they are way worn. Macmac has written many times about this. He recommends measuring the freeplay and using some sort of shim to keep movement to much less than that. Search the garage section for his previous comments on swing arm posts. You should not have enough room for a washer if the seals are intact. I would recommend tearing it apart to investigate. It is all straight forward with some basic tools, time, and shop manual. Parts are not bad at cheapcycleparts.com

[VulcanE]

Yep, sounds like the seals are worn, but that amount of play is typical. They are cheap at the Kawi shop, but require the removal of the swing arm to install. Even with new seals, you'll still have around .090 to .100" of freeplay. Ideally, you only want about .002 - .005" of freeplay (left & right). If you can shim it, that's great, BUT, you need to shim both sides equally, not just one side.

[macmac]

Yup .... How many miles? Seals are a dealer item, unless some after market company bought some. The part number is 92049-1181. It is likey the head pipes will need to come down if they are not OEM system. If this is true then the head pipe gaskets should be replaced rather than used over. Head pipe to head gaskets number is 11060-1119.

I forget the matching Harley head pipe gaskets some guys use.

The swing arm by the book should be serviced each 7,000 miles. The first time should not be missed, while I would wait for the need of a new rear tire myself. That would be around 7,000 to 9,000 miles with the junk they install from the factory anyway.

The swing arm set up is made wrong. Unadjustable needel bearings are used, and there is no way to set preload. A bike on the show room floor new is likey to be very sloppy here where the tolerance should be 0.02 inch.

1/8th inch is way too much, but my 1500 went to past 1/10th, and was at 0.138 when I became very aware of handling going south....

I can not come up with a real good fix. New seals alone are not the best option.

With the swing arm service done, this is what I will do next time. The service is a done deal the swing has been installed, and then measurements WILL occur, and the swing arm WILL be removed again.

In this case instlled means leaving the rear wheel off, the drive shaft off, and maybe only installing both shocks and the long bolt for getting the measurement.

You would take the reading by first pulling the arm to you, and then pushing it away, to get the measurement. No 2 bikes will be the same.

With this in mind, then you need to see a machinist. The seal ID will be the hole he cuts in the material of your choice. The OD will be just 0.010-0.020 bigger than the seal.

Each spacer will be 1/2 the total slop.

Hard nylon is where I will go the first time, and if that works well, I may try it again, or do the same on gun bronze for the slippery properties of that alloy. In metal grease and lube all surfaces.

The damnned seals with still wear out on the backside because some fool who thinks he is an engineer, used them as thrust washers.

[macmac]

This has nothing to do with the swingarm service.... Just incase someone thinks so. Do that as std proceedure.

The shims are too thin to make in two pieces, and then screw together which would allow assembly installed.

[ndbigfish]

What about using two fender washers that are opened up for the diameter of the shaft which holds the swingarm on? Each fender washer is approximately .060" thick.

[macmac]

Well the ID needs to be the same as the ID on the spacers, of which 2 are semi external of the total 3 spacers. .060 depends on the gap and no two bikes will be the same gap no matter what. Hard nylon or babbit, or bronze, or brass are probably a better material that mild steel and might be considered slippery.

There is no way around measuring gap with new seals, so the best way is to just install the swing arm, torque it and set up the shocks to gain the Measurement, with no drive shaft, gear box and rear wheel.

Get the measurement divide that by 2, and then decide what material will suit you best. Steel would not suit me at all, but thats just me. That bloomin seal sets my tea kettle right off.

I let a engineer see this problem and he was angered that another quasi engineer could even see fit to have used these parts in the places ma kawii did. Doing this was more than just plain stupid. The other thing I don't like is the water pump drive. A lot of makers do that too, but that don't make it right.

It's a good thing there is a cheat to do that inner oil seal after getting the water pump off, other wise it is a $1,500.00 labor fee for replacing a 10 cent seal.

This is what you get with a guy who can run a CAD, and other wise never once got his hands dirty.

[ndbigfish]

Mac,
Any idea what the inner Ø of the seals are? I would like to find a commerical washer that is the right inside Ø and work the thickness from there. That way I have the washers in hand when I pull the swing arm at the next tire change and I can mill the washers to the correct thickness and reduce down time.

[macmac]

ndbigfish, ummmm no. I could measure the spare seal sets I have on hand here, but it won't work. I would need to get the measurement from my end spacers to be exact enough. More over I have no way to determine the thickness of the 2 shims your bike would need already waiting to be measured up.

If it were all that easy i would have been making shims for sale. I can't guess which bikes are even close to a standard shim size in terms of thickness. So then the problem would be to guess what is the most standard shim size to make and pray they fit someone's bike. Which isn't likely.

Maybe.... you can push the swing arm over, pull it back, with the wheel off the deck of course, then push it back again and see the right side spacer. Then sneak in there where you are certain to see a gleeming spacer and get it's OD. Might be digital calipers will just get in there, maybe not. No mich will, that fer sartin!

These bikes look similar parked to one another, but that is where exact ends. These bikes vary in more than 10ths' of inches in the frame specs, forks specs and etc and are very loose in terms of tight accurate exact matched frames and other parts.

I know this to be true since I added Phatt II risers and I modded all the nacell fitting, the speedo mounts and anything to gain clearance and could not get it. The end result 2 small dents.. I can live with them.

These swing arms are wildly irregular from the next one. There is just no way to take a measure of mine, and expect it will match one other bike on the planet.

[Cajunrider]

Mac,
How about setting up a dial indicator on a magnetic base and zeroing the indicator with the swingarm shoved fully inboard? Pull the swingarm out till it stops, take a reading and go from there on the washers thickness.

[trosco]

That's eactly what we do when we check end play on a crankshaft. CJ. Let's us pic a rear main bearing with the proper thickness on the thrust surface. It should work. If some one hasn't done it by then I will when I do my next rear tire (pretty soon as have 14k on current stone, but then that is a whole nother story isn't it!!!)

[macmac]

Originally Posted by Cajunrider

Mac,
How about setting up a dial indicator on a magnetic base and zeroing the indicator with the swingarm shoved fully inboard? Pull the swingarm out till it stops, take a reading and go from there on the washers thickness.

Yup you can do that, or use vise grip mounted indicators padding the jaws with rags or leather. But that is a uncommon tool for most, and a decent calpier will do in either dial read out or digital, using the slider rod depth finder part of the tool.

The only time saver I can dream up is to do the swing arm service, then install the swing arm and one shock to get the reading with no gear box, no wheel and no drive shaft.

This for no more than to get thickness of the shims.. The shims being spacer OD on the shim ID, the shims being bigger slighty maybe 0.0.20 over seal OD (0.010 over all see?)

And splitting the measurement in 1/2 in the hope to end up with 0.002" free play in side to side slop. Made of something hard, but self lubrication, so the back of the seal lasts longer. AND polished to a mirror like surface no mater what is used, again to not wear the seal backing.

When it is right, I would expect some swearing would be involved getting the inner seal spacer in place...

Still this doesn't make it right.... It will still wear, and still kill the seal, it should just take longer to wear in to 0.125" slop unfortunately.

i was hoping someone a lot more creative than me, and I am, would figure a better fix than I can concoct..

[sarc]

what are the signs and symptoms of that free play. I use to get vibration/grinding noise from back end. got the rear wheels bearing fixed. stll noise. slow speed turns were hard to do. felt like bike wanted to jerk down. I fixed the free play with spacers. will test ride later (still snow lol)