Which oil for smoothest gearbox?

[Speedy1959]

On a previous post about puncture repairs and whether they are regarded as permanent, it was suggested I ask about oil (tongue in cheek)..

When I picked my bike up last week from a Yamaha dealership they had just done a service. They used the Motul 5100 10W-40 semi synthetic in the bike..
When the engine is cold / warm the gear changes are deliciously smooth..
When the engine is hot (at operating temp) the gear change is quite notchy (sometimes difficult to get neutral).
My previous bike (Yamaha MT-01) had a totally different feel to the gearbox and I had got used to that.. It was a longer action if that makes sense..

My question is..
Which oil seems to give a smooth gear change.. I assume this must make some difference because the engine and gearbox share the same oil.

S.

[Kiwifruit]

I was using Motil 5100 and not 100% happy with gearbox feel. Going from neutral into first was terrible, the clunk was embarrasing. So tried Motul 300V  three times the price but no better. Have changed to a cheaper Gulf Western Australian oil and am now happy with the gearbox. Though i believe every gearbox has to be gotten used to.
The English boys will be along soon to point you in the right direction.

[DTTW]

Without taking part of the oil part of of this discussion, rather some personal observations about the gearbox and changing the gear.

Most of you probably know that when the engine is "cold" the bike is running on higher RPM. Always a good idea to wait until you have your idle settled to nominal figures before engaging first gear. I have also noticed that sometimes when I change from neutral to first with "pushing" the bike onwards just that little and softly pressing the gear lever down it helps to reduce that clunk effect. Someone can probably explain the theory behind this.

For the rest of the gears (changing up that is) what I do is I lift the gear lever slightly, I try to take the "slack" off from the lever movement until the point when the next gear is being engaged (you can try to find this point by moving the lever with your hand when bike on side stand and engine nor running), simultaneously on that point releasing some throttle, then pulling clutch in and giving that final push for gear lever. Most of the time this works as a treat and I have totally smooth gear change. I have noticed that at least the gearbox on my 14 is not as accurate as with the newer bikes, who would have guessed.  For example I tested brand new Suzuki SV650 and that gearbox was smooth as silk. I could not even made it clunk even I tried... better stay away from newer bikes if you want to stick with the 14 

That is how I do it. I cannot say how much oil brand/type has effect on a smooth gearbox operation and how much of the not-that-smooth operation is being created by the driver, or me.    I have always used Motul 5100 10W-40.

[Sweaty]

I changed from Fuchs Silkolene comp 4 semi Synthetic (very expensive) to an Aussie brand, Penrite Full Synthetic at less than half the price. Definitely better gear changes, but still the clunk into 1st which is normal.

See what the local lads have to say soon.

[gsxbarmy]

I always used Silkolene comp 4 semi Synthetic and had no issues, in fact was very happy with that oil.
Others in the UK on here are very happy with Halfords 10w/40 4 Stroke Part Motorcycle  Part Synthetic Engine Oil, as you get 5 litres, enough to do oil and filter change

Do read through the (sticky) tech tips on the forum though Speedy - see these threads relevant to the "oils" subject:

http://gsx1400owners.org/forum_test/index.php?topic=17.0

http://gsx1400owners.org/forum_test/index.php?topic=435.0

[Andre]

Changed from a JASO-MA spec to a JASO-MA2 oil. That made a, however minor, difference.

Oil can't perform miracles. It can't change the hardware.

I am going to look at a couple things in the future based on suggestions found on the net:

a) Spring (PART NO: 09444-20001), which sits on the gear shift shaft, loosens strength (even several cases where it broke - with and without resulting engine damage). After replacing it, shifting was much smoother.

b) Pushrod - someone measured the thing and found it to be worn out (shorter). After replacing with a new one, shifting (clutch separation) was smoother. Where the pushrod contacts the slave cylinder piston wear down can be present as well.

[T 24]

People are talking how the gearbox works with some oil... Mostly it comes from how the clutch is working with some oil. (imo)

[grog]

clunk into first is just how it is. i dont have any change problems with mine. a very sweet gearbox.

[HLAH]

mines at 16K, i change the oil every 5K & use expensive Motul crap mainly because I tend to be a little ham-fisted with the gear (stomping on levers, poping clutches, rushing/forcing changes etc..)...

Was told big suzuki bottom ends are bullet-proof...I guess Ill find out...

It gets a bit clunky & misses the odd gear when the change becomes due but that all goes away with fresh oil...

[Speedy1959]

Once again..
Thanks to you all for your replies.

S.

[Hooli]

Change the clutch fluid & while you're there pop the slave off to clean the pushrod & make sure the 'front' of the slave where the rod sits isn't full of road crud. 9 times out of 10 it's a filthy pushrod sticking in the block on mine, they get plastered with chain lube & road dirt.

Oil wise, Halfrauds 10w40 semi bike oil every 4k seems ok. Mine runs quieter on it than others I've tried & at 113k it still doesn't use any. I guess it's run enough to be sure now...

[Speedy1959]

Is it fair to say that this clutch fluid hadnt been changed for a while ?

S.

[Hooli]

Mine comes out the slave that colour every year.

Maybe the mod somewhere on the forum using busa? bits to keep crud out the slave would help, I've never bothered to find out.

[Notty]

Just bought some Castrol from Halfords 20% off - wait and see how it is - oil change due now but should I leave it until spring ? won't be riding much more now winter is here 

[Speedy1959]

I have never hibernated my bikes over winter..
But obviously I pick and choose the days with OK weather (Just like the "Summer")..

Going on "The Hercules Run" charity bike ride tomorrow and of course its set to pee down !!
Just been out (in the car) and bought a full set of waterproofs..
I WILL enjoy the ride..
I Will enjoy the ride...
I will . . . . . .