Though the DRZ has a very strong clutch straight from the factory, eventually it will need to be inspected and or replaced. Thats where this quick article comes in... This walk though is not a replacement for common sense, a factory service manual, and some amount of general mechanical experience. As always, if your not sure, ask
Here on TT or from another trusted source.
.. Now lets get to it..
There are several reasons to inspect the clutch...
-As part of a normal tear down at season end
-As part of an engine rebuild / upgrade
-Upon noticing excessive clutch material or aluminum bits in the oil.
-Experiencing clutch slippage under load
Replacement parts are available from several sources if needed.
A trusted aftermarket vendor for everything needed; clutch springs to billet forged basket is MOOSE RACING (parts reference on the last page). If your just looking for some new clutch drive plates the OEM ones from Mother Suzuki are hard to beat.[BREAK=Tear down and inspection] This procedure can be done without draining the motor oil, by laying the bike down on it's side... In a pinch I might do this. But normally I'd recommend just waiting till you needed to change the oil if it's just a clutch service check.
If your digging in to replace parts due to slippage, the oil is contaminated and needs to be replaced in any case. I also find it easier to work on bikes at chest level,, Leaning over a bike on the ground is ok if I have to.. but getting old sucks in more then one way.
1: First thing you need to do is get the foot brake lever out of the way.
You'll need an 8mm hex key or bit to remove the pivot bolt.
2: Next remove the 6 hex head screws that retain the cover. Use a 8mm socket to do this.
You will find two different sizes
3: Once the cover is off this is what you will find
the clutch pressure plate is held to the hub sandwiching the disks by 6 socket head cap screws (#9). Each will have a special washer (#11)that helps keep the spring (#10) in place.
Remove all six screws
4: The clutch drive plates (aluminum friction disk) and clutch driven plates (the steels) are stacked on the clutch hub alternating each type.
On to the inspection [BREAK=Clutch inspection]
So its all apart, cleaned up and ready for the inspection.
We are going to look at four areas;
-pressure disk
-clutch hub and basket
-drive and driven plates
-Clutch spring free length
1: pressure disk... look for any warping of the friction surface, or grooving that runs radially around the friction surface. If it is warped, or grooved,, time to replace.
2: Hub and basket... Looking for grooves on the hub where the steel driven plates wear against the hub(the "teeth"). And grooves on the basket where the clutch drive plates wear against the basket fingers.
3: Drive plates and steel driven plates...
The drive plates are checked for three basic things..
-General damage, warping, cracks, and such
-Claw width
Services limit : Claw Width - minimum 13.2mm. Make sure you measure in several different places. If any of your measurements are below the service limit, the drive plate needs to be replaced (yes you could replace them individually, and thats what the OEM sells them that way,, personally, I always replace them as a set, and normally, if one is bad, the rest are also.)
-Drive plate thickness (at the friction pad)
Services limit : Plate Thickness - minimum 2.62mm . Make sure you measure in several different places. If any of your measurements are below the service limit, the drive plate needs to be replaced.
-Driven plate (the steel ones) The are checked for warping
Service Limit: 0.1mm
The plate should not be warped in any direction, curled up from the edge to center, or radially around the circumference. Bottom line, if it does not lay flat on your inspection bench, it's no good, replace it.
A thick piece of glass makes for a good flat test surface. Often you can get a piece cut as a glass shop for next to nothing, ask for tempered glass. When you get it home make a wooden box for it and store in a safe place until next time. I've had the same 18"x18" 3/8 thick piece for more then ten years now.
-Clutch springs... This is a simple check, using a set of calipers measure the free length of the spring. make sure you not compressing is with the calipers when doing this.
Service Limit : 49.9mm
Check all of the springs, if any of them are shorter then the service limit, replace them as a set.
[BREAK=Installing the clutch]
So every thing has checked out or been replaced as needed. Time to reinstall the clutch... but it's never that simple.
There are OEM parts, aftermarket parts copied after OEM parts, and aftermarket parts that have to be installed slightly different. I will detail the aftermarket changes in BLUE
NOTE if your installing NEW drive plates, soak them in motor oil before installing them. Installing dry new plates will cause quick failure.
1: Take your pile of driven plates and find the one that has a larger INSIDE diameter.. This is the first plate that you will install. Look at the hub, and insure the shudder springs are correctly installed
If you are using an aftermarket clutch set up. compare the drive plates,, if all of them have the same smaller size ID, then you DO NOT USE the OEM shudder springs.. IF one of the aftermarket drive plates has a larger ID like the OEM set, them reuse the shudder springs.
Install the first drive plate, then a driven plate (they are all the same), alternate until you get to the last one.
NOTE: There is no reason to off set the last drive plate, it does not effect installed stack height, it does not effect travel of the plates as you actuate the clutch. You can find references to it both ways. It does not make any difference. line um all up, or off set the last one a notch left or right, what ever you prefer, it will work the same.
2: Install the pressure disk, the 6 springs, then the screws with cupped washer.
Tighten the springs down in a star pattern
3: Check the O ring seated in the back side of the clutch cover, make sure it is fully seated all the way around. give it a LIGHT coat of oil.. just enough that will help it slide across the case as you tighten down the screws. Install the 6 screws into the cover, yes there are two different sizes, no you really can not get them mixed up. See the picture for a reference of where they go...
4: Reinstall the brake lever,add a new cotter pin if you want (never had this bolt loosen up on me,, but that pin must be there for a reason)
Add oil if you drained it as suggested... Go ride.
[BREAK=Parts reference]
Moose Friction plates
Price: $69.74
MFR Part #: F70-5255-8
Product Code: PU_F7052558
Moose Spring Set
Price: $7.70
MFR Part #: MHDS81-6
Product Code: PU_FHDS816
Moose Steel plate set
Price: $32.23
MFR Part #: M80-7210-7
Product Code: PU_M8072107
Moose billet clutch basket
Price: $141.79
MFR Part #: M252
Product Code: PU_11320099








