Hydraulic Clutch Adjustment for Stelvio and Others, Better Shifting

[leafman60]

With almost 35,000 miles on my NTX, I have recently noticed some occasional shift lever resistance when shifting. My fix was to adjust the clutch lever to accommodate mechanical wear and provide a deeper stroke of the master cylinder piston to produce a more certain release of the clutch.

Remove the 10MM locknut from the bottom of the lever pivot pin screw and remove the screw.


Remove the lever from the handlebar perch and loosen the grub screw that secures the threaded master cylinder pushrod.


I put an index mark on the pushrod and threaded the pushrod out a couple of turns to tighten up the brake cylinder. Do this in careful increments and be sure to tighten the grub screw when finished.

Clean everything up, apply some new lubricant to the lever pivot pin and hole as well as the pivot connection of the pushrod and reinstall the lever. This may be a good time to flush and bleed the system with fresh 5.1 fluid.

If you extend the pushrod too much, you will lose necessary minimal slack in the master cylinder piston that allows it to properly return in its stroke. This adjustment method can be used to vary the clutch engagement point of the clutch lever either way, early or late.

You can see the adjusting threads on the pushrod in this picture.

[ohiorider]

Good recommendation.  I also made the pushrod adjustment on my 2012 Griso, but had to 'tweak' it in the opposite direction.  My bike shifted smoothly, but the clutch was not engaging until near the end of lever travel.  Made me question whether the clutch was totally engaged when the lever was released, not to mention putting a load on slightly arthritic joints.  A turn or two to shorten the rod (in my case) brought the clutch take-up closer to the mid-lever position.  BTW - good close-up pix of the mechanism.

[Wayne Orwig]

Clean and lube the aluminum pivot point well.
Mine wore and the lever disintegrated. That was a fun ride home.  :o

[lucian]

Great info , thanks leafman. I have heard the grub screw can be a bugger, did you have any problem loosening yours? Also wondering what the recommended lube is? I am also curios about the relationship between the length of the push rod to the travel on the master cylinder. Other than free play wouldn't the fluid being displaced be the same regardless of the starting point of the stroke? Assuming there is no  air in the system. By lengthening the rod, are you essentially compensating for wear throughout the mechanically linked side of the clutch? ie. pivots throw out bearings ect. Hope that makes some sense.

[Vasco DG]

Do be careful if attempting this. The adjustment is very fine. If you extend the plunger too far it won't allow the piston to fully return and it will block the priming hole. This leaves the system closed and heat from the clutch will preload the thrust beRing and, if serious enough reduce the clamping force on the clutch and it will start to slip.

Pete

[leafman60]

Great info , thanks leafman. I have heard the grub screw can be a bugger, did you have any problem loosening yours? Also wondering what the recommended lube is? I am also curios about the relationship between the length of the push rod to the travel on the master cylinder. Other than free play wouldn't the fluid being displaced be the same regardless of the starting point of the stroke? Assuming there is no  air in the system. By lengthening the rod, are you essentially compensating for wear throughout the mechanically linked side of the clutch? ie. pivots throw out bearings ect. Hope that makes some sense.

The grub screw was not too difficult to move. Yes, it feels as though it has some thread locking feature to its threads but it turned okay.  Be sure to use the exact sized allen wrench to prevent wallowing out the hex socket of the screw.

My reference to lube was directed at the pivot pin connection of the lever to the handlebar perch and the pivot connection of the pushrod to the lever. I used a small dab of grease inside the lever itself before inserting the pivot pin and a short spray of multipurpose oil inside the overall mechanism when assembled.

Yes, lengthening the pushrod as shown basically compensates for mechanical wear. And, yes, you must not extend the pushrod so much as to eliminate needed slack that allows the master cylinder piston to properly return. If you accidentally do this, however, you will encounter difficulty inserting the perch pivot pin to the clutch lever when reassembling since you will be having to compress the master cylinder piston into its bore in order to align the perch pivot pin hole. You don't want to do this.

By the way, this may also be a good time to flush and bleed the clutch fluid with new 5.1 fluid. That always makes the action feel better.

[toma nova]

I'm trying to add shorty levers with better reach adjustment (and some bling) and can't get the grub screw out.  Before I round it off on the stock lever, does anyone know where I can find a replacement screw?  I'll also buy a good 1.5mm hex wrench to make sure I'm using the correct size.

TIA,
Tom

[leafman60]

I'm trying to add shorty levers with better reach adjustment (and some bling) and can't get the grub screw out.  Before I round it off on the stock lever, does anyone know where I can find a replacement screw?  I'll also buy a good 1.5mm hex wrench to make sure I'm using the correct size.

TIA,
Tom

Try finding someone who stocks metric set screws.  It can't be too long, though, or it'll stick out and cause interference.

[Triple Jim]

Do be careful if attempting this. The adjustment is very fine. If you extend the plunger too far it won't allow the piston to fully return and it will block the priming hole. This leaves the system closed and heat from the clutch will preload the thrust beRing and, if serious enough reduce the clamping force on the clutch and it will start to slip.

Pete

One of the guys at the 2-stroke meet last week replaced a broken brake master cylinder lever with an aftermarket one he got from a local shop.  It didn't take long for exactly what you described to happen to him, only with the front brake!  He was riding along, and the front brake went on hard, all by itself, and he went down for the 2nd time in two days.  It taught a lot of us to be sure the lever isn't applying pressure to the master cylinder piston when it's released.

[Scott of the Sahara]

My shifting got much better when I drained and replaced the Hydraulic fluid.
aprox 25,000 miles.

[leafman60]

My shifting got much better when I drained and replaced the Hydraulic fluid.
aprox 25,000 miles.

DOT 5.1