Clutch Dragging On My 2008 280Txtpro - *problem Solved*

[laser1]

1st thing to do is try the proper amount of oil. 400ml. Sorry - the 08 manual is wrong. It was like that for years! I know what a PITA. You would think a manual would be correct. Not with GG. They are famous for it! The latest manual is correct in the US and lists 400ml. If not - you can verify the correct amount on the rising sun website. (GG usa Parts importer and GG expert mechanic Jim Snell or verify with Jon Stoodley (JSE) via PM or call GGuk. Extra oil will cause drag. However, many time the problem is hydraulic with leaking seals ect..FWIW: Its always good to verify the finger height as well.

[seavoyage]

Posted on a separate thread:

Many GasGas Pro owners experience clutch drag. The GasGas Pro clutch is very sensitive to the 'finger height' and the currently available complete clutch pack is too thick resulting in noticeable drag - the slave cylinder 'top hat' can't engage the 'shallower' finger height to hold tension or complete disengage. If a 2.00mm steel plate is replaced with a 1.30mm-1.50mm steel plate, the finger height will be too high resulting in slip - top hat stays engaged.

I recently replaced my Pro clutch pack and discovered the following:

GasGas only sells the complete clutch pack MT280232055 : 3 Friction plates MT280232051 and 2 steel plates.MT280232050 . See note below..

Current steel plates in the complete clutch pack measure 2.00mm .

2002-2003 clutch packs were different MT280432055 . Early 2002 friction plates MT280232051 were prone to swelling; current friction plates do not swell in ATF.

The 1.50mm MT280232050 , 1.40mm MT280232050/4 , and 1.30mm MT280232050/3 steel plates are no longer available. If used with the current clutch pack to replace one of the 2.00mm steel plates, the overall thickness will be too thin.

If, post 2006 model, both steel plates measure 2.00mm and the friction plates vary in thickness: one friction plate is 2.20mm and the other two measure 1.80-1.85mm for a overall thickness of 10.00mm? ( I realize the math doesn't add up from the factory specs)

AND

The correct specification is: No less than 9.75mm and not more than 10.05mm

How do we build a clutch pack that measures 9.75mm +/- 0.1mm to acheive the desired 17mm +/-1mm 'finger' to inner hub depth?

I ended up going through all my old friction discs to build the appropriate clutch pack.

I had trouble reverse bleeding the clutch and discovered one of the two orifices in my AJP master cylinder (small reservoir) was blocked. I couldn't clear the blockage; so I replaced the master. I discovered that the master cylinder bore and stroke was relatively the same between the AJP long and short reservoir styles.

Replaced the O-rings in the slave cylinder for good measure. The GasGas Technical Bulletin (10/2006) updated 10/2012 http://www.trialspar...ober_2_2012.doc recommended conversion from DOT4 to mineral oil. We since converted back to DOT5 by replacing the slave cylinder O-rings with MT280432047..

We found the Carquest part number CTC407008 for Viton® O-rings for the slave cylinder a bit tighter fit than the OEM MT280432047

Note:

2006 and newer model Installation note: The clutch fiber and steel discs were changed in the 2006 model year. The three fiber discs have a variation in thickness and the two steel discs are thicker than the previous models. There may be slight variations in thickness of the fiber discs, this is done at the point of manufacture to ensure precise total pack width. The total pack width is 10.0~10.01mm – The two steel discs measure 2.0mm each – Two of the fiber discs measure approximately 1.80~1.85mm thick and the third one is 2.2mm thick. All steel and fiber discs are symmetrical (there is no specific front or back side)

IMPORTANT: Of the three fiber clutch plates, one is noticeably thicker. (about 2.2mm thick) This thickest plate MUST be the one that is placed into the engine first. (Farthest into the interior and against the rear surface of the center clutch driven hub.)

Edited July 19, 2013 by seavoyage

[mic]

Still not happy with my clutch but have not been riding much lately, decided to remove the clutchpack and check again today, noticed that all fingers are not equally high, see picture.

The complete clutchpack height is 9,75-9,8mm, the bottom fiberplat is 2.2, the other two are 1,8mm, the steelplates are 2mm each.

However if i place the steelplates on a glass surface i can see that they are a little bit warped, not much but still enough to be seen.

Could this cause the problems im having?

Also there was some strange wear/burn mark at some parts on the outer side of the steelplates.

[charlie chitlins]

The fingers get grooves in them at the big end where they take stress...and it's never even.

I tell ya...I did everything.

Went through a pile of plates, got the pack the right height, rebuilt the master and slave, blah, blah...it still slipped.

The day that bike left in somebody else's pickup truck was a happy one.

[mic]

If anyone has the same problem i can tell you what fixed my clutch, ordered a master cylinder rebuild kit and fitted it the other day, bleeded the system and filled with fresh oil and all problems are gone.

The clutch is now working just as i want it to, thanks to everyone that has been giving me help, hopefully this thread might be of use to someone else with simular problems.

If anything i have atleast learned alot about my bike

[sawtooth]

If anyone has the same problem i can tell you what fixed my clutch, ordered a master cylinder rebuild kit and fitted it the other day, bleeded the system and filled with fresh oil and all problems are gone.

The clutch is now working just as i want it to, thanks to everyone that has been giving me help, hopefully this thread might be of use to someone else with simular problems.

If anything i have atleast learned alot about my bike

Happened to me recently too, only after buying and fitting a new clutch did I find out that my slave had been slowly leaking oil into the engine. Couple of slave cylinder seals and a power bleeder from Halfords did the job. Clutch is perfect now and does not drag at all ;-)