GEARBOX OIL

[NOSHER]

HI GUYS--ANYONE KNOW IF YOU CAN USE SEMISYNTHETIC OIL IN THE GEARBOX GIVEN THAT IT HAS A WET CLUTCH??

KR1
CBR250RR
CBR400RR
GSXR600 SRAD

[the-elf]

Nope it'll cause clutch slip. Best to use good cheap mineral gearbox oil.

[NOSHER]

THANKS ELF--SHOULD HAVE ASKED BEFORE I CHANGED THE OIL FOR SEMI SYNTH ""-GOOD JOB I HAVEN`T STARTED IT YET--OUT WITH THE OLD DRAIN TRAY AGAIN!!

[alimorg]

THANKS ELF--SHOULD HAVE ASKED BEFORE I CHANGED THE OIL FOR SEMI SYNTH ""-GOOD JOB I HAVEN`T STARTED IT YET--OUT WITH THE OLD DRAIN TRAY AGAIN!!

Nosher, caps lock off mate - capitals = shouting!
Cheers
AL

[NOSHER]

SORRY MATEY --HAS TO BE DONE--I`M 65 YEARS OLD AND THE OLD PEEPERS AIN`T WHAT THEY USED TO BE--PLUS I`VE GOT THIS STUPID BLACK KEYBOARD WITH SILLY LITTLE WHITE DIGITS SO I NEED ALL THE ASSIST I CAN GET---PLUS DON`T YOU THINK ITS A LITTLE OLD HAT TO KEEP SAYING THAT PEOPLE ARE SHOUTING IF THEY EMAIL IN CAPS??I DON`T MISPELL MY WORDS IN CAPS UNLIKE A LOT OF EMAILERS USING LOWER CASE!!
A LITTLE LENIANCY FOR A PENSIONER PLEASE MY FRIEND.

[alimorg]

SORRY MATEY --HAS TO BE DONE--I`M 65 YEARS OLD AND THE OLD PEEPERS AIN`T WHAT THEY USED TO BE--PLUS I`VE GOT THIS STUPID BLACK KEYBOARD WITH SILLY LITTLE WHITE DIGITS SO I NEED ALL THE ASSIST I CAN GET---PLUS DON`T YOU THINK ITS A LITTLE OLD HAT TO KEEP SAYING THAT PEOPLE ARE SHOUTING IF THEY EMAIL IN CAPS??I DON`T MISPELL MY WORDS IN CAPS UNLIKE A LOT OF EMAILERS USING LOWER CASE!!
A LITTLE LENIANCY FOR A PENSIONER PLEASE MY FRIEND.

I am not having a go its just not good Netiquette - you wouldnt shout at people in the pub or in the street!

If you need to increase the size of the text on this site (works for all oter sites as well) I have made you a little walk through on how to do it here:

Making text bigger on the forum

In this example I am using Internet Explorer 7, but Safari, Firefox and others all have the same capabilities, you might just have to look around the menu items to find where they are.
Hope this helps,
Cheers
AL

[alimorg]

Nosher - if you need me to make another with the specific web browser you are using let me know and I will get it done ASAP
Cheers
AL

[smithyrc30]

Nonsense my boy.....

I say all this talk of wet clutches and synthetic oil causing slip is pure tosh.

As an example, do you believe that standard mineral oil is what is used in modern state of the art automatic transmissions?

I can tell you they use synthetic, bloody expensive synthetic at that (current ZF oil price is 9:30 per litre) Doesn't sound so bad until you realise you need 10 litres of the stuff.

I digress, auto transmission fluid is designed specifically for gears and wet clutches. On a two stroke you can use specific gear oil, so why not?

Standard ATF that you get from Halfords/Repco is semi-synth usually called dextron 3 or equivalent. I use the ZF stuff in the KR, it is more expensive, but you don't need that much. It works a treat and to boot is as thin as buggery and according to the specs remains the same viscosity all the way up to 150C. (It has an upper temperature limit of 190C). The only way you can get to those temperatures on a KR is if the bike is on fire, and then clutch slip is the very least of your concerns.

According to some test work I have done, the oil is worth about 2Nm parasitic torque saving on a ZF. (Doesn't sound like a lot, but it is about 4%). If you work back through the numbers, 2Nm at 10000 rpm is about 1kW or about 1.35bhp.

Cheapest hp you will ever buy......

[headcoats]

The LC folks use Silkolene light gearbox oil SAE 10W-40

[smithyrc30]

This is still too viscous, it is for baulk ring cone synchromesh transmissions and is designed to help the rings transfer torque. It does not have the ability to anti foam nor does it have the correct wet clutch friction packages.

Fine in your car, but bugger all use in a motorcycle. Better than engine oil, but not by much!

The effective SAE weighting of auto trans fluid is about 2~4, but the kinematic viscosity is what you really need to look at as this defines the amount of energy the oil needs to be moved. This is where the losses come from. Remember all the gears in the transmisison spin all the time, and were the teeth contact they are like miniature pupms. (Very ineffiecient pumps because thay are not cased, but pumps nonetheless). High ratio gear sets like 1 and 2 are the worst for losses.

Added to that ATF has anti foaming agents which help heat transfer, increase lubrication and increase fluid life.

[the-elf]

from painfull experience most synch gear box oils cause clutch slip on a KR. On more modern bikes there's no problem but KR's seem to hate the stuff.

Best thing I've found is Halfords own brand Motorcycle gearbox mineral oil.

[alimorg]

So ATF is the way to go? where do you buy the ZF stuff cant seem to find it!
Cheers
AL

[smithyrc30]

I'm using the ZF stuff in my KR right now....

Just done around 2000kms (in the pissing rain I might add) over the Snowies, and it is not slipping one bit.

Not even got new clutch plates in, they are still in their bags with the KR-1R springs.....

The engine clutch has about 35,000kms on it.....

I guess you get what you pay for. Like I said before most gearbox oils are for manuals with synchro cones, not wet clutches. Autos use wet clutches (and one way clutches too, bit we don't have slipper clutches on the KR, don't need them on a 2 stroke) Manual oils generally do not work in auto's, the clutches need friction modifiers to work (so they don't snatch/grab or squawk) so these are the ones to go for. As 4 smokes need to use common oil with the engine they need very high temperature stabilizers, which [color=red]can[/color] cause issues in wet clutches that are not working correctly. I run fully synthetic oils in my 4 smokes and have had no issues with clutch slip.

The ZF stuff can be bought from Jag Land Rover dealers (ask for the stuff for the auto cars built post 2002, they all use it.) Do not expect it to be cheap.

BMW dealers sell it, same deal autos in 3, 5 and 7 series from 2002 will make sure you get it. If the car they quote you for has 5 gears it is not the stuff you want.

Mercedes use something very similar in their transmissions but only the 5 speed and 7 speed units. This covers most of the upper range from about 1999.

Ford have a similar product, for their 5 speed, but the only usage of this I know of in Europe is the Jaguar S type form 1999 to 2002 when the ZF 6 speed took over. This might be available from Halfords, branded MERCON 5. You will know if it is because it will be expensive (around double the price of the normal stuff) and will smell like cats piss. They all do it is the friction modifiers. Some stink worse than others.

Oh a thought just occurs to me, Ssang-Yong use the Mercedes 5 speed and 7 speed in their Kyron and Chairman cars (they have a deal with Mercedes) and you may be able to get it from them as well (if they have any dealers left that is...) Make sure you only get the stuff for the 5 speed or 7 speed trans, the stuff for the 4 speed is conventional mineral and a very old spec as well.

Not sure what GM have, but I don't think they have synthetic in anything in Europe.

If your crank seals ever start to leak, you get a real early warning, it smells bloody awful when burnt, so you know instantly.

[TwoStroke Institute]

VMX 80 is the Ford product $35 for 4 litres at Super Shite Auto, been using that for more years than I can remember.

[Charles]

VMX 80 is the Ford product $35 for 4 litres at Super Shite Auto,

but that's actually from Castrol?!

http://www.stealth316.com/misc/castrol_vm_80_gl4.pdf

Charles