GS1000 from click to clunk

[Lorenzo]

Since I had this bike, I experienced the annoying first gear engagement clunky noise, which, becoming aware of, I determined to solve;

Deep in winter, when temperatures average 5°C-41°F (so far), I started to notice that, upon starting the bike from cold, and for the next five minute or so, the noise produced by the engagement of first gear, was akin to a clik!! Reverting to the embarassing clunk (and lunge), from then on.

Having not attended any mechanical improvement so far, only changed the oil with an 10W40, I was wondering if, this behaviour, could be accounted for to the oil gradation:

1) being it more fluid at low temps (10W) and not enough at he higher ones (40) so that when the engine warms up, the oil cannot cope for the best, calling for a 10W50;

2) or, is the fluidity of the winter part of the specific (10W) to high for the state of wear of the transmission, making it work OK until is cold, which would perhaps call for a more viscous one (20W50).

To sum it up: 10W50 (possibly 5W50) or 20W40?

Thanks

[tom203]

What brand/type of 10-40 oil are you using? Mine clunks going into first when cold,lessens as bike warms up. Maybe the "click" is due to looseness in shift mechanism somewhere.

[Lorenzo]

The clicking noise is what I am aiming at;

Do not know what was in there before, but I changed it with Castrol (eehm) Magnatec none of which was satisfactory;

Tom, what oil do you use, since your symptoms seem just the opposite from mine;

Maybe the "click" is due to looseness in shift mechanism somewhere.

Maybe the "clunky" noise is due to .....

I was thinking to one of the possible avenues, of being the gear shift cam (the sort of star shaped cam, between the shift pedal and the secondary;

http://www.cmsnl.com/suzuki-gs1000-g-1980-1981-usa_model15990/gear-shift-cam-driven_2532231310/#.VLuaYvmG-Rs

Another possibility is, that (again) the oil, with it's specific gradation, is not holding the input shaft still (well, sort of) allowing it to spin to a rate that is causing a collision with the output, upon engagement.

I know that with the abovesaid, I introduced another possible culprit, the clutch itself, but since it's pulling without hesitation, from 1500 rpm in fifth gear, I still think the oil has something to account for;

Again, when cold, the clutch plates could bind tigthly, and when the oil gets hot, slip a little bit... another reason for a different grade oil (OK, OK, I know that the Magnatec might not be the best for a wet clutch, but what about the previous one?)

Anyway, I am planning to use a 20W50, either Castrol Activo or an Elf mineral and see what happens.

I once had a car with a faulty third gear sincro that would not allow me to shift the relevant gear; before I completely gave up, and looked for a reconditioned tranny, I decided to change the oil (manual transmission fluid) with the good old (now disappeared it seems) Tutela ZC90.

Well, you wouldn't believe it, the poblem had since gone.

That fact made me think about employing a thicker (more viscous) oil.

Thanks

[zuzu]

Not sure if this brand is available where you are. Its what many of us prefer. Shell Rotella 15-40 diesel oil. It is excellent for wet clutches and has a higher zinc content.

[chef1366]

Did you try tightening the clutch cable a little?

[tom203]

I use Shell Rotella 15-40 diesel also. Since you go down for first, maybe there's a little slop in the pawl/spring area.

[Big T]

Its more likely the type of oil rather than the vicousity

Shell Magnate is a car oil, with additives that can harm the wet clutch.

Try switching to a motor cycle specific oil, or diesel oil as suggested above and see if the problem goes away

The clunk and lunge points to the clutch as the issue

[Lorenzo]

Tony and Tom, you both seem to use 15W;
this could validate the correctness of my line of reasoning.
I will enquiry about the possible different branding of the Rotella, for the E.U. market.

Chef, I stand by the fifth gear progression from low revs, to determine if the clutch (and cable) are in spec, but I will try with micrometric adjustments.

Since you go down for first, maybe there's a little slop in the pawl/spring area

I have never handled the pawl; if you have do you reckon there is something to rebuild there or rather overspec?

BigT your answer arrived while I was typing; so you might not have read my previous line above, bike has no judder nor slip at the entire rev range, but I take it as a point to investigate.

Thanks

[Nessism]

The problem described is very unlikely to be oil related.

Listen to Chef and tighten the clutch cable. If the clutch adjustment doesn't help I suspect the issue is with the clutch plates. Warped fiber or steel plates will cause drag and clunky shifting. Getting some new OEM Suzuki parts should take care of the issue. Easy for me to say though since those are not cheap parts.

[blowerbike]

Ed is the voice of reason...
and the zinc is just about gone from the rotella....blame the government.

[Lorenzo]

blower, yes I have read a couple (at least) of threads -threads that amount to a religions war- about the additives that have been removed from the mix of oil, and about the opportunity of using car (even diesel) vs bike oil, and I gathered that one the most important factors, is oil not containing friction modifiers.

But here I would like to have feedback on different viscosity of oil.

Ed, as I said, I will try to set up the clutch cable, from the perch, after having changed the oil to 20W50 for the sake of comparison, still I think that if it where the cable, the symptom should be present at all temps, which is not my case, bike cold=click bike warm=clunk, but no stone will be left unturned...

Thanks
P.S. Oh no, I am reading yet another article about oil, this very moment......

[Grimly]

Ed is the voice of reason...
and the zinc is just about gone from the rotella....blame the government.

Some, ahem... 'racing' oils still have plenty of it.

[blowerbike]

Some, ahem... 'racing' oils still have plenty of it.

racing and off road oils have large amounts of zinc but the rotella everyone preaches of has been robbed of most of it.

[Grimly]

racing and off road oils have large amounts of zinc but the rotella everyone preaches of has been robbed of most of it.

Yep. I was looking for the European Shell equivalent of Rotella and here, it's the Helix range. Difficult to get any real info on it, except some odd snippets from BITOG, where the occasional poster might have done a UOA. As far as I can see, the only Helix oils that would be worth putting in the bikes are only available in 205L drums, for truck maintenance shops, so not across the counter.
I sidestep the issue by adding zinc via blending in some Champion Racing oil, and lately have bought some Total Racing with the same view, but the zinc level in that is dropping, too.