8 replies to this topic

[jamessut]

Just wanting some advice about which is the best oil to use in my Gas Gas txt pro 2004, clutch fluid and gearbox oil as i am changing next week any advice would be appreciated. Thanks

[curt531]

Hi, clutch must have a mineral based cluth/brake fluid in it or the seals wont last, gear box have ATF, personally I use a BP product in the clutch & Silkoline ATF in my gearbox on my 2005 Gasser, hope this helps

[JanDyb]

curt531, on 02 October 2011 - 06:16 PM, said:

Hi, clutch must have a mineral based cluth/brake fluid in it or the seals wont last, gear box have ATF, personally I use a BP product in the clutch & Silkoline ATF in my gearbox on my 2005 Gasser, hope this helps

Nono.. the mineral oil in clutch is from 2005, so unless the pumps are rebuild to use mineral oil, You should use normal brake fluid dot 4 (or 5) on a 2004.

ATF Dexron III works good in gearbox.

-Jan

[jamessut]

Thanks for the replies, what would happen if someone before me used mineral oil instead of dot 4 reason I am changing it is clutch seems to be heavy compared to others and my forearms are like popeyes after a short time

[JSE]

JanDyb, on 02 October 2011 - 06:23 PM, said:

Nono.. the mineral oil in clutch is from 2005, so unless the pumps are rebuild to use mineral oil, You should use normal brake fluid dot 4 (or 5) on a 2004.
-Jan

If the clutch is designed for mineral oil use, the top cap on the M/C will be a green color (black color for DOT-3/4/5.1).

DOT 5 is not compatable with DOT-3/4/5.1 fluid and is Silicone based.

Jon

[JanDyb]

jamessut, on 02 October 2011 - 07:36 PM, said:

Thanks for the replies, what would happen if someone before me used mineral oil instead of dot 4 reason I am changing it is clutch seems to be heavy compared to others and my forearms are like popeyes after a short time

Jon is of cause right. Dot 5 and Dot 5.1 is not the same.

But..If Your clutch is heavy it probably is because Your clutch fibres are swelled. This makes the clutch pack too thick which again makes the moment for the clutch "fingers" wrong. (search the forum and you will find plenty of posts regarding this).

If you remove clutch cover you can easily measure this by measuring the hight of the "fingertips". It should be about 17mm. Thicker clutch pack means lower fingertips and harder clutch action. 0,1 mm difference in clutch pack makes 2 mm difference in fingerheights.

3 solutions:

1. Buy new clutch pack.
2. Adjust clutch pack by changing the metal plates in clutch pack to thinner ones. Trialendurodirect.com used to sell these in different thickness, but I dont know if they still do.
3. Carefully sand clutch fibres by using fine sandpaper (600+) on a glass plate. This can work but if you make fibres uneaven new clutch pack is only solution.

-Jan

Edited by JanDyb, 04 October 2011 - 11:45 AM.

[laser1]

Another improvement to any 05 clutch is to switch to the 06+ clutch spring. Its 20% lighter over your current spring and makes a huge difference.

[jamessut]

Thanks for all the advice, going to measure the plates whilst I have everything drained.

[JanDyb]

JanDyb, on 04 October 2011 - 11:44 AM, said:

2. Adjust clutch pack by changing the metal plates in clutch pack to thinner ones. Trialendurodirect.com used to sell these in different thickness, but I dont know if they still do.

-Jan

Found the steel plates:
http://www.trialendu...plates_291.html

-Jan