Rear Swingarm SWAY

Discovered that my rear swingarm moves right to left about a quarter inch at the chain adjusters. (as if there were a new vertical axis perpendicular to the existing one. Up and down as was designed, now right to left as has worn.)

The back end did seem to steer/float/shift a little bit on me. particularly while rear braking, or downshifting.

Took the wheel, chain, shocks and finally the entire arm off.

Visually everything appears fine. Go figure. Therefore I can't imagine this to be an abnormal wear condition, i.e. crash damage, freak chance act of god failed and broken part, or vandalism. It is just an old bike, and the parts have some play in them now.

Are there parts that are commonly replaced?

Or do I just need to live with the sloppy backend?

Simple fix? Expensive? Hard to find the parts? Illegal in some states?

I just turned forty, and one sloppy backend is all that I need.

P.S. I blistered my right index finger on a pop-tart this morning. Of all things. Might account for the sloppy backend though.....

Is the whole swing arm moving?, or just the wheel assembly? If swingarm, you may have some worn out bushings. If wheel, you may have some bad wheel bearings.

1977 used bushings, 1978-up used 4 needle bearings. Needless to say bearings are better. I don't know if it would be possible to convert a 1977 to bearings or not. The way the bushings work in 1977 was they had a grooved tube riding in the bushings. When you pump grease into the zerk, grease is supposed to travel along these grooves into the bushings. The grease turns to a mixture of hard dirty sludge at best and really no way to get grease into the bushings. When you disassemble, you'll find your tube a rusty mess, and if you replace the bushings which are about $80 for the two of them, the tube will no longer fit into the new bushings. You'll either need to replace the tube $100 or so, or spend a lot of time with emory cloth sanding.

For reference if needed---







4 33001-1007 SWING ARM 1 KZ650-C1
4 33001-1080 ARM-COMP-SWING 1 KZ650-C2~
5 92005-002 GREASE NIPPLE 1
6 33034-024 SLEEVE,SWING ARM 1 KZ650-C1
7 33032-050 SHAFT,SWING ARM 1
8 43007-047 TORQUE LINK 1 F/NO.000001~023100
9 92003-218 BOLT,HEX HEAD,10X39 1
10 461F1000 WASHER SPRING 10MM 3
11 314B1000 NUT,10MM 1
12 554A0800 PIN,SNAP 1
13 92003-197 BOLT,RR TORQUE LINK 1 F/NO000001~023100
14 42045-021 NUT,12MM 1 F/NO000001~023100
15 550D3025 PIN COTTER 3.0X25 1 F/NO000001~023100
16 92001-1577 BOLT,FLANGED,8X35 2
17 461F0800 WASHER SPRING 8MM 2
18 33044-002 STOPPER,CHAIN ADJUST 2
19 33040-056 ADJUSTER,CHAIN 1
20 312B0800 NUT 8MM 2
21 92001-1399 BOLT,8X50 2
22 45014-117 SHOCK ABSBR RR 2
23 45017-015 BUSHING,SHCK ABS RUB 2
24 45016-008 BUSHING,SHOCK ABSORB 2
25 45017-012 BUSHING, SHCK ABS RU 2
26 92020-014 NUT 12MM 2
27 461F1200 WASHER SPRING 12MM 2
28 410B1200 WASHER PLAIN 12MM 4
29 113N1035 BOLT HEX HEAD 10X35 2
30 42036-1012 SLEEVE,SWING ARM 1 KZ650-C2~
31 92046-1115 BEARING-NEEDLE,HK221 4 KZ650-C2~
32 43064-007 DAMPER RUBBER 2
33 33040-1003 ADJUSTER,CHAIN 1 F/NO.000001~023100
33 33040-056 ADJUSTER,CHAIN 1 F/NO023101~
34 43007-049 TORQUE LINK,REAR HUB 1 F/NO.023101~
35 92001-1145 BOLT,10X47 1 F/NO.023101~
36 461F1000 WASHER SPRING 10MM 1 F/NO.023101~
37 314B1000 NUT,10MM 1 F/NO.023101~
38 554A0800 PIN,SNAP 1 F/NO.023101~

they can be converted from bushings to bearingsB)

PLUMMEN wrote:

they can be converted from bushings to bearingsB)

Can you just use the 1978 parts I wonder? You would need 4 bearings 92046-1115 at about $10 each, the sleeve 42036-1012 at about $25. The parts that worry me is the endcaps are different part # on the 77 and 78 meaning maybe the diameter of the bore in the swingarm could be different as well as the part # for the swingarms themselves are different with the 78 being about a $60 more price tag. Would be great and cheaper parts if the 78s could be fitted.

That bike must have suffered some serious neglect or something has come loose or been modified. My '77 KZ650C1 has 46k miles and after reading your posting I just checked the swingarm for play. There is absolutely no play. Before I started buying parts, I would disassemble it and find out what's wrong. Have you owned the bike long and did this problem just start, or is it possible that (if you recently bought the bike) the previous owner switched swingarms with another model or did some other modification? Don't worry, if you decide to replace the bushings and sleeve, you can find them inexpensive (total for all about $80) on eBay & Z1. (new endcaps can also be found for a couple bucks) Examples follow:

sleeve

bushing

sleeve2

Post edited by: 650ed, at: 2008/02/02 23:05

RonKZ650 wrote:

PLUMMEN wrote:

they can be converted from bushings to bearingsB)

Can you just use the 1978 parts I wonder? You would need 4 bearings 92046-1115 at about $10 each, the sleeve 42036-1012 at about $25. The parts that worry me is the endcaps are different part # on the 77 and 78 meaning maybe the diameter of the bore in the swingarm could be different as well as the part # for the swingarms themselves are different with the 78 being about a $60 more price tag. Would be great and cheaper parts if the 78s could be fitted.

use the newer parts and have a good machinist line bore or hone (cant remember,its been a long time)to make sure things are straight;)

One of my 750s had the same problem, and I had about 1/4 inch play in either direction. It turned out that the swingarm needle bearings were toast. All it takes is years of neglect, and a total lack of grease.
:lol:

For me, I had to buy a new sleeve (hard to find) and replace all the bearings (easy to find), but the work was a big pain. I beg everyone, for the sake of their bike's future owners, to go pump some damned grease into the swingarm!
:whistle:

Thanks again for all of the great postings.

Yea, the grease had completely solidified. It had the consistency of tar.

I have had the bike for a year. The prior owner had crashed it into a pole.

I have replaced so much of the bike so far, that I might as well continue on.

The design for the grease fitting does not seem too conducive to getting the grease to the bushings. It would seem better to disassemble and grease by hand huh?

Yeah that gease fitting isn't the best ... I took my swingarm off and thoroughly cleaned and hand greased everything ... added a new zerk and then finished filling the cavity. I would say that once every year (winter) this would be an easy maintenance chore. It's really not too hard just a bit of tinkering.