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Transmission woes

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6.1K views 13 replies 4 participants last post by  Jaredkaragen  
#1 ·
so, when i bought my K3 600, i knew it had a slight issue with the transmission. This problem isnt unexpected for me.

please excuse typos, im stuck using my cellphone that spent 30 min on the bottom of a pool two weeks ago. im lucky it still works :)

Symptoms:
coasting in gear the transmission whines, in neutral, the whine is non existant.
idling you can feel a lump/rough feeling that is regular to the engine speed, and smooths out harmonically with an increase of rpm. pull in the clutch, and the feeling disappears. I felt this originally when i parked on a slab that had a sinkhole under it so it amplified the feeling. Its steadily been getting worse.
whining under cruise and acceleration. less whine under decel.

so i now know this via the info above:
The mainshaft (input shaft) bearing 'ISB' opposing the clutch is surely bad. the ISB behind the clutch may be going out.
the countershaft bearing seems ok given the coasting in neutral diagnostic.
The gears/sliders themselves are probably not worn or damaged due to the coasting in neutral diagnostic as well.
I can also rule out clutch basket bearing because of the clutch pull in idle/neutral.

So, I luckily scored a full gearset with bearings from ebay today (no purple, clean gear faces/edges, etc) for $29+25 shipping.

I plan to go through a step by step photo taking process of the repair for the community as an fyi.

If i dont source a temporary engine, i will use an airplane a-frame cherry picker to lift the bike by the front tire to gain access and do the work with the engine in the bike.

My questions:
Has anyone else has these symptoms or issues? Is it common on this bike for some reason? Is it just bad luck for me? Does my diagnostic seem sound? I was the lead, then only repair/diag tech at an auto shop for well over 3 years.

Any suggestion of things to consider replacing while im in there, such things like how older models had the hollow shift shaft and whatnot?

I will measure and inspect the forks when its apart and order as necessary. If the supplied bearings i get are at all questionable i will order new.

Thanks for the input, its much appreciated.
 
#3 ·
My thought is the basket spins all the time. How would that bearing go absolutepy smooth with clutch pushed in? Its pushing out on the mainshaft... which pulls (in theory due to play) the mainshft to the left side of the bearing, which given the weight of the clutch and symptoms of left bearing, would not make enough sense to me.

I tried to think about the mechanics of my symptoms as much as possible to this point.
 
#4 ·
And the wine is mostoy the straight cut gear noise. Like a pete jackson gesr drive sound. So i know its moving enough to mess with the mesh and contact surface.

Sinc the gearset was cheap, i simply bought it as a standby.

I planned to go inside the clutch housing on my oil change soon. But, i am planning for the worst, because the ultimate goal at some point is acquire a full motor for temporary use and rebuild my original. I need to get any special pullers first of course. I know ill probably need one for the stator rotor at some point, but didnt check yet if theres one for the basket.

Ive built several bike engines (74 xl350, 91 GSX 750, 87 cbr 600 hurricane, 86 FJ1200, countless car engines, and countless small engines of many types) so i'm not jumping in blind.

Im extremely happy theese have a 3 piece case design. I loathed doing my old GSX. Annoying.
 
#5 ·
Ok, my uber cheap gearset came in and i picked it up yesterday.

I swear, it must have less than 5k miles on it. The only damage, if you want to call it that, is a slight amount on the dogs and engagement area of the gear that is furthest from the output "front" sprocket on the countershaft. No damage or marks on any other gear or dogs. I am amazed at inly paying $56 shipped.

So, with the saved cash, i am going a step further and getting a starter clutch and idler gear, shift forks, new bearings all around (bushings on gears are excellent), and possibly a shift shaft.

This trans replacement has turned into a full bottom end rebuild, simply because its easy and affordable.

At the same time, oil pump, water pump rebuild, clutch basket bearing, clutch plates as needed, cam chain guides, and cct.

I will try to take pictures of the process and give clear explanation of the processes for everyone else who is considering doing it.

I will either source a temporary engine, or do a winter teardown and service of the bike, engine and all.
That is, if i feel like fixing up a car to commute during the winter time.
 
#7 ·
Anyone who has owned an auto with a bad input shaft bearing knows the exact sounds im speaking of.

I have had a couple people (mechanics included) agree that it sounds like a mainshaft issue.

Mine stays in gear, is very rough between gears (completely unlike my friends k3 600), has popped out of 2nd several times (shortly after shift at any rpm), one false neutral into 6th, and the dreaded 2nd gear kick which feels like it momentarily pops out of gear. This is all with firm shifting action.

With it having 47k miles, i dont mind refreshing the engine and shimming the valves if necessary. I dont think it will be, my idle and power are up to par. Head to head with another 03 600 that has 14k miles.
 
#9 ·
Gripe:
Every other transmission references an input shaft, and a countershaft respectively.

Suzuki's twisted idea/industry standard:
Countershaft/mainshaft
Output shaft/countershaft

Sooo backwards retarded that was to find out.

End gripe.

Now, for anyone whose been in there, the factoey parts catalog references the bearing sizez, which are rather large.
The image shows tiny ass needle bearings on the shafts opposing the clutch and output sprocket. Are the images in the catalog just misleading?


Secondly,

Does anyone have the main bearings for this gearset out of an engine? Could you read me the part numbers off the bearings? They wont be the suzuki oem number, it will be a skf, nte, or other bearing number. I am trying to locate an interchange number to not pay the ridiculous bearing prices. Every rime i have done this i have saved well over $100....

Thanks!
 
#10 ·
so, suzuki uses a japanese bearing brand, and all of them have some sort of special modification weather it be a alignment pin, a slot, or hole in the race. poo.

im two bearings, 3 shift forks, and 3 seals away from having enough parts.


on a side note,
my charging system failed. 0ohm across all 3 stator wires (200ohm setting), tested another known good bike on the same meter and got .2 ohm. i also get 0 ohm to ground.
I have been having starting issues, sounds like when a kick start engine kicks back.
once it locked up while cranking and i had to put the bike in gear and bump it past that section.

soo, i ordered an extra stator cover gasket, a high output rewound stator, the mofset regulator, and the charging system monitor.

i know the cranking noise is coming from the stator side. i just hope my magneto rotor isnt effed up.

but, its still in the works as of now. Projected rebuild time is middle of next month. i havent got my cars new engine swapped in yet.
 
#11 ·
you are going to have to remove the engine from the frame to get to the transmission...
 
#13 ·
Image

Stator in. Gonna dis-re-semble the bike tonight to get this sorted.
$45.95 unit from ebay, windings are an 8 of 10 as far as tightness. The whole unit is a 9 of 10 rating. Ill report my reviews on it as well. Not a bad price for what you get.

It was sold as "High Output", so im assuming a heavier gauge winding.