As an engineer I have closely inspected the design of the compensator. Here's what I see.



As removed:

The various components:


Left to right: 3368 Screw, 6445 Washer, 40297-06 Shaft Extension, 40333-06A Cam Slider, 40356-07 Rotor & Spring Cover Assembly, 40320-06 Compensating Sprocket

It's important to understand how the design is supposed to work. Here's what I believe to be the case:

The only component that is supposed to move horizontally in line with the drive shaft is the "Cam Slider". As torque is applied to the shaft the mass of the motorcycle resists motion. This results in the sprocket pushing the Cam Slider into the spring assembly. As the torque begins to equalize the spring, pushing back on the Cam Slider should cause the Cam Slider to move back out along the splines of the Shaft Extension.



Shaft Extension mating with Cam Slider, sprocket not shown



Shaft Extension and Cam Slider

Unfortunately there is too much surface area in contact between the Shaft Extension and the Cam Slider. Furthermore the fit between the two parts is too tight, particularly if the spring is fully compressed and the Cam Slider pushes far enough into the spring assembly which will happen under highest torque differential. As the parts wear damage to the mating surfaces can and does occur. This damage can actually increase the friction between the parts. The static friction is such that the parts do not slide freely but instead bind. A large torque differential is required to cause the parts to "break free" of one another.



Damage to Shaft Extension spline



Damage to Cam Slider spline



Sprocket showing impact damage. The breaking free results in impact damage to the Sprocket. Note the impact damage to the outer surface of the sprocket also suggests the sprocket has moved laterally which would put lateral strain on the primary chain leading to accelerated wear.

The wear on these parts resulted from 6,500 miles of use on a 2010 Limited. I highly recommend that everyone who has not already done so replace this part with the SE Compensator. Will the part fail you? Chances are no. Will the part result in unnecessary wear on other drive train components? Probably. Will the riding experience be improved? Definitely.

 

Nice write up!

 

Great post, I talked to my dealer today about what he is seeing on 08+ comps and bikes coming in. He of course said, no problems good part. HAHAAHAHAHAHAHAHAHAH. That is why the dealers never touch my bike...

 

Yeh, that's how I ride! Guess I have no worries! LOL!

(Actually, when I swapped out my 5spd gearset for a Baker DD6, they included their own compensator.)

 

Awesome write-up and pics Dave. I guess we'll get a look at what mine looks like when we pull mine at your house on Saturday.. Well take some more pic's so we can show what, if any, damage has occurred on my 09 with 12K.

 

It'll be intersting to see what yours looks like Clint,
D

 

subscribed; great pics and writeup Dave

 

My '07 FLHTC developed what felt like a lot of slack in the driveline at about 40K. Drive belt was tight and there is no way to check the primary chain without pulling the outer primary. My thought was that the self adjusting primary chain tensioner had failed.

It was the compenstor, everything else was fine. The compensator was still within specs, but just barely and the amount of slop was very noticeable. I was not aware of the SE compensator at that time and do not know if that is what was installed. I have since traded the bike.

 

How am I supposed to know if mine is bad or on it's to crapping out...?

 

I went ahead and changed mine to the SE comp with about 3K miles on the original. I heard a different knock in the primary, so the dealer (who installed the new comp) removed the primary and found the new SE comp had just sustained pretty extensive damage...similar to the pics above. They changed it out with another SE comp and replaced it....same sound. They took it BACK out, and inspected further. They found the inner primary tranny bearing was failing. WTF??!! Great job on their part to find and diagnose it, though. All under warranty (thank God!) the work was done. I took her out for an easy 600 mile ride the next day and it went great. The SE comp provided an obvious torque improvement between shifting, and my starts are crisp and very positive. No more of the "kick back" like somebody smacks the primary cover with a 2x4 when the starter disengages. A GREAT MOD...don't let yours fail you, it could be catastrophic. Nice write up, Sir.