ZG1000 C10 Rear Suspension Play - Normal? RESOLVED

[Stasch]

On my 2000 C10 (108K), there is a normal LINEAR lurchiness / snatch felt through the bike if I turn throttle on and off, on and off abruptly.

Under the same conditions on my new to me 2003 C10 (67k), there is a SERPENTINE lurchiness / snatch felt through the bike. I first started noticing this on a mild basis when modulating throttle going through turns.

Engine mount bolts checked. All there, torqued properly.

With the rear wheel blocked to allow relatively zero tension on the rear shock rocker assembly:

2000: No movement at all, although it appears there is some gap in the mount to the frame by the centerstand.

2003: I can feel movement on the right lower dog bone at both top and bottom mounts, but not the left.

I can also could see and feel significant side to side movement at the front rocker mount where it bolts to the frame between the two large ears.

Right Side Video:

Left Side Video:

With the rocker off the bike, there is some bolt to bearing play in the middle rocker connection (dog bones connection) when moved manually.

There is no discernable bolt to bearing play for front and rear rocker mounts.

I understand how up and down slop could develop, but side to side?

Could this play be the cause of the SERPENTINE phenomenon?

Is the play at the front of the rocker normal? It seems like its something that should be shimmed although I've never seen that before.

 

[mgoodrich]

It looks to me from your video that whomever took apart the rear suspension forgot to put the seals back in when they reassembled it. I don't see them in there, and that would take up the slack that you are seeing, in both areas.

My suspension is tight in those areas, no back and fourth movement. The seal number is 92049 on the parts fich.

That is probably why you are experiencing the weird serpentine motion.

 

[Bud]

It looks to me from your video that whomever took apart the rear suspension forgot to put the seals back in when they reassembled it. I don't see them in there, and that would take up the slack that you are seeing, in both areas.

My suspension is tight in those areas, no back and fourth movement. The seal number is 92049 on the parts fich.

That is probably why you are experiencing the weird serpentine motion.

Good catch!

 

[connie_rider]

Stasch, the seals have steel inserts in them. Think of them as thrust washers.
If they are not there, you would have the slack.
You would also have dirt/grit in the bearings which probably caused wear.

Here is all you need (plus- extra parts) for about $10.00.
Came off of a low mileage 2004.
Buy it and install. Problem solved.

Ride safe, Ted

1986-2006 Kawasaki Concours ZG1000 SHOCK BRACKET LINKAGE SUSPENSION ARM UNI TRAK | eBay

Find many great new & used options and get the best deals for 1986-2006 Kawasaki Concours ZG1000 SHOCK BRACKET LINKAGE SUSPENSION ARM UNI TRAK at the best online prices at eBay! Free shipping for many products!

www.ebay.com

 

[Stasch]

It looks to me from your video that whomever took apart the rear suspension forgot to put the seals back in when they reassembled it. I don't see them in there, and that would take up the slack that you are seeing, in both areas.

My suspension is tight in those areas, no back and fourth movement. The seal number is 92049 on the parts fich.

That is probably why you are experiencing the weird serpentine motion.

I had the rocker completely removed and all the seals are there, they don't show up in video.

 

[Stasch]

Stasch, the seals have steel inserts in them. Think of them as thrust washers.
If they are not there, you would have the slack.
You would also have dirt/grit in the bearings which probably caused wear.

Here is all you need (plus- extra parts) for about $10.00.
Came off of a low mileage 2004.
Buy it and install. Problem solved.

Ride safe, Ted

1986-2006 Kawasaki Concours ZG1000 SHOCK BRACKET LINKAGE SUSPENSION ARM UNI TRAK | eBay

Find many great new & used options and get the best deals for 1986-2006 Kawasaki Concours ZG1000 SHOCK BRACKET LINKAGE SUSPENSION ARM UNI TRAK at the best online prices at eBay! Free shipping for many products!

www.ebay.com

The steel inserts must be integrated in the seal as parts fiche's don't show them.

I have a complete set from a 31,000 mi. C10.

Going to take off this suspect set again and inspect more closely.

 

[connie_rider]

Have a seal in my hand. & Yes, the steel is part of the seal.
If you have a complete set, (including bearings) change it out and you're done.

Ride safe, Ted

 

[Stasch]

Swapped in 31,000 mile rocker / dog bone / bolt assembly. Took on test ride - still had issue.

However, I had no more play that I could force by hand. Interestingly, the front rocker mount to the frame still had left to right play before shock was attached and everything torqued down. This must be normal as I can also see space there on my 2000.

I also noticed I did not have play when holding the rocker and moving the dog bone bolt / pin like I did on the original set. It could be those got hammered due to the following actual cause (read further), or that it was normal all along.

I am not sure the theory of the steel inserts in the seals were part of the issue, as all of them were in place on the original set.

Continued looking further - - - > the nuts that hold the final drive on were loose. Should've noticed that right away. A couple were actually backed off away from the flange. Tightened back down to 22 ft/lb with blue loctite. Issue resolved - no more side to side flex felt in frame.

Never had these come loose before. I changed out rear tire 450 miles ago and my process is to R&R the pumpkin along with the wheel.

The only scenario I can think of is I failed to torque them back down? If so: double on me.

I include this possibility even though it would mean I was an idiot, as it might help someone else.

 

[2andblue]

Swapped in 31,000 mile rocker / dog bone / bolt assembly. Took on test ride - still had issue.

However, I had no more play that I could force by hand. Interestingly, the front rocker mount to the frame still had left to right play before shock was attached and everything torqued down. This must be normal as I can also see space there on my 2000.

I also noticed I did not have play when holding the rocker and moving the dog bone bolt / pin like I did on the original set. It could be those got hammered due to the following actual cause (read further), or that it was normal all along.

I am not sure the theory of the steel inserts in the seals were part of the issue, as all of them were in place on the original set.

Continued looking further - - - > the nuts that hold the final drive on were loose. Should've noticed that right away. A couple were actually backed off away from the flange. Tightened back down to 22 ft/lb with blue loctite. Issue resolved - no more side to side flex felt in frame.

Never had these come loose before. I changed out rear tire 450 miles ago and my process is to R&R the pumpkin along with the wheel.

The only scenario I can think of is I failed to torque them back down? If so: double on me.

I include this possibility even though it would mean I was an idiot, as it might help someone else.

OMG - those nuts being loose one could imagine a big problem occurring, glad you found them loose on your time and not after something came apart.

Good idea on the Loctite as well!

Wayne, Carol & Blue

 

[Stasch]

It couldn't have been catastrophic as I took it off the road once I began to feel something wasn't right.

Still racking my brain to recall if I torqued them since it was several hundred miles after reinstall and that its only 22 ft/lb. Its the only thing that really makes sense if thought out objectively.

I believe the axle would hold things together over on the right side of the swing arm, unless signs continued to be ignored, leading to increasing squirrely-ness (a complex latin term).

Then I guess anything is possible if damage to parts began with potential lockup (?)

Wouldn't want to find out.

 

[connie_rider]

Glad you found the culprit.
The loose nuts would have allowed the differential to move a bit.

I'll look at the suspension on my C-10 when I get a chance.
Want to see if I have any of the side-to-side movement that you have at the rocker/dog bones.
(Bike is not here) So, it may take a few days.

Ride safe, Ted

 

[Stasch]

I'll look at the suspension on my C-10 when I get a chance.
Want to see if I have any of the side-to-side movement that you have at the rocker/dog bones.
(Bike is not here) So, it may take a few days.

Ride safe, Ted

I had to get the rear wheel jacked up a bit on boards so there was ~zero pressure on the linkage system in order to get it to move.

Glad you found the culprit.
The loose nuts would have allowed the differential to move a bit.

Definitely. I had the idea to hold the front brake and letting out the clutch to apply some power and I could see some movement at that joint, then noticed the loose nuts.