Rear shock linkage maintenance

[Auburn]

This is to show what happens when you don't do the maintenance.

I'll start by referring you to a very good resource with pictures and diagrams for doing the service. https://www.fjr-tips.org/maint/sa/sa.html it gets you into the swing arm and other linkage points also.

The background on my rear suspension: I installed a Penske 8987 shock on the bike at 5800 miles on 1/10/08. I have done no service to it until 12/29/12. The bike currently has 33,670 miles on it. When I bought the shock from GP Suspension they recommended servicing it every 20,000 miles. I noticed that it was not performing as well as it should about 5000 miles ago.

In December 2012 I had the shock serviced by the new owner of GP suspension (KFG Racing in Auburn, WA). The shock had 27,870 miles on it.

I got a call from GP to come take a look at the shock. Here are pictures of the shim stacks. They show lots of corrsion in the shims. The shims are varying thicknesses and diameters of stainless steel.

Below is the assembly that goes inside the remote resevior. It needs to be rebuilt do to the corrosion. This caused additional expesne that could have been avoided with a more regular service schedule

Ill add more photo of the shock internals when I get them from GP Suspension. I can say they looked pretty bad.

With the shock out I decided to check all the linkage points and remove the swing arm and lube all those points too.

Here is the lower shock linkage diagram

At this point in my pictures the swing arm is removed. The linkage is still in the bike, and you have to remove the center stand to get the linkage off.

Linkage off, left side bolts the frame, right is the lower shock bolt and the center is the lower dog bone mount. Note the corrosion on the bolt that goes through bushing (piece #19 in the diagram)

Here is the linkage looking from each side

The bushing removed - looking through at the bearings - note the bearing side of the bushing had a little bit of an oil film and the bearings moved smoothly and were fine.

The dog bone bolts after cleaning up with wire brush and 600 grit sand paper.

The Shop Manual calls for lithium soap based grease to be used. My experience from my dirt bikes with soap based greases on shock linkages is that is washes out quickly and is not very effective. I started using a marine grade moly lube originally made by JetLube.

Here is where I get it at McMaster-Carr on line. Part number 10625K11 for $16.71 for a 1 lb container. https://www.mcmaster....18/2166/=kwm2ey NOTE: the name has changed to Dow Corning but the part number and specs are the same as the Jet lube I use.

Here is a picture of the label of mine (I repackaged into an old silkolene container)

On my dirt bikes, the linkages look like I just did them after a year of riding in the mud and pressure washing the bike to clean. I also use this lube on all the axles and any place that has a bolt going through a bushing.

To be continued.

 

[Fontanaman]

Looking forward to more information. My 09 has 36,000 miles. KFG installed a Penske shock at 30k miles. This post helps me decide on my service intervals. My goal is to have this done around 15k miles.

Like you I used to ride dirt bikes. I recall changing the front fork oil after far too long. The oil was black and had an awful stench.

Thanks for posting!

 

[Mr Bill]

This post helps me decide on my service intervals. My goal is to have this done around 15k miles.
Like you I used to ride dirt bikes. I recall changing the front fork oil after far too long. The oil was black and had an awful stench.

I think different riders will have different intervals. The pieces they sent back from my shock looked pretty good after three years and 25k miles. They told me the fork bushings looked fine and my three year interval seems to be fine for my ride. I don't commute and the bike sits a long time between rides, but the rides are usually multi day or at least long days so everything heats up.

I can't believe AuburnFJR shined up those wishbones like that. I'll have to get some sandpaper.

 

[road runner]

Holy double post

I use a good lithium soap base grease (like crimson red) on the brgs and OD of race (bushing)and seals. Then use a good marine grease thats waterproof and won't wash off, on the bolt shafts so they don't corrode and get stuck in the race. The waterproof marine grease is called Special lube 101 grease. https://www.marine-products.com/mercury-marine-quiksilver-101-lubricant-with-teflon-92-802865q02.html

This stuff is very sticky and waterproof. It won't wash off prop shafts so it won't wash off any of your bike linkages. It has Teflon in it so not for needle brgs. I use it on high friction areas and a corrosion preventive layer such as bolts/bushings, relay arm bolts, shift linkages, rear brake linkage, axles, not on brgs. You only need a very thin coating and it will stay in place. It's like never seize in that a little goes a long way but I think it works better. Any Mercury Marine dealer should have it on the shelf.

 

[Fred W]

I'm due to do this suspension linkage stuff (again). It will be interesting to see what kind of shape my bearings and spacers are in after having done the last service to them 2 years and ~ 30k miles ago. Probably worth noting that Auburn lives (and ostensibly rides) in the Pacific North Wet. It's a lot drier in most other parts of the country and I'm also kind of a "fair weather" recreational rider.

 

[LAF]

Just did this and it was due. I sanded and steel wooled everything to shiney and smooth. It was not a fun job at all but it looked to me like it needed done at 20,000 miles.

Odd that others never touch them and all works fine.

I can tell you I packed them well with grease and had it mushing out everywhere at reasembly. I wiped it all clean and called it good to go.

Yhe only wear on what people call bearings were on the shock hole all others looked new. They are not bearings in my opnion, I look at them as bushings. The hard stuff in between the metal is a hard wearing surface, not wax as others have said. It wears as the metal does, so I call them bushings.

Happy I did it but it will not get done in another 20,000 miles maybe on it's 50 or 60,000 mile birthday?