gear problem's on an 'M' Model?

[johnakay]

(((Long rides in 5th, hot summer days, and no chance for the 5th gear to rest and cool all can lead to eventual failure.))))

what do you call long rides?
here 200 to 300 miles in a day seem to be the norm.
and probably in 5th gear continues about 25 miles at the most unless motorway road.

[johnakay]

Huh. That looks problematic too. Doesn't look like it's firmly held in place.

The kick start shaft goes over top of the dam, see where the screw hole is in the casting, it's highly unlikely it will come out, the kick start shaft mounting clip keeps it down in place

any chance of a picture.
you would've thought I'd know about this have about 5 x 500 two strokes.
to be honest I'm not clued up on engines.
I'm OK cosmetics etc but thats about it.

[Bloop2]

A few pics for you, the dam without the shaft, kick start shaft installed and the final pic shows the clip that holds the shaft in place.

[Suzsmokeyallan]

Thanks for those photos of the dam installed Fred.
The problem was an oil level that was too low, putting the dam in and raising the level by 200cc was the cure. However Suzuki never changed the outer casting to reflect this, only placed a decal onto the case which in itself caused problems.
Imagine this scenario, the upgrade and the decal is in effect which should solve the issue, BUT along comes someone who fills the case up till the level screw mark thinking its correct, as you normally would do.
Now you've got 1200cc again with a dam in place, the fifth gear is still going to be starved of oil.

[johnakay]

thanks Fred. learn some thing new every day.

[ConnerVT]

A touch of sealer to hold it in place doesn't hurt, either.

[Bloop2]

A touch of sealer to hold it in place doesn't hurt, either.

Highly recommended for the repro dams that are sold on Ebay, they don't fit that well.

[argo1974]

I have four 73" T500 and they came without oil dam from the factory.
Frankly, when I first heard the oil dam mod provided by the factory, I had to laugh. 10mm additional height and 200 ml more oil will decide the gears wearing out or not?
Finally, I went with special oil dam (higher than 10mm) and 2L of high quality GL5 rating synthetic transmission oil. I hope, it works.

[Rustygt550]

Most of the later t500's with the modified oil level get their 5th gear destroyed by the crank seals going and sucking gear oil & lowering the gearbox oil level.

Thats what happened to my M model, the previous owner just rode the bike on & on with the crank seals gone which lowered the oil level & wrecked 5th gear

[Ivan]

I have a 75 M model in my shop at this time, and it says 1400cc on the case (next to the filler cap)... What year did they start showing 1400cc on the case?

Ivan

[argo1974]

Copied from this article: http://www.classicbikersclub.com/articl ... zuki-gt500" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;

"Indeed, two years later in 1977 Suzuki, no doubt keen for any positive publicity for the bike, provided one for long-term test. Colleague Stewart Boroughs took it to the West German GP at Hockenheim, covering more than 1300 miles, mostly on autobahns. Never one to pussy-foot, Stewart cruised at 75mph but it never missed a beat, and on return the drive chain needed just over a turn on the rear spindle screw adjusters. Fuel (at just 85p per gallon!) was used at 42mpg and oil at 330 miles per pint. It wasn’t all good news though. At 2700 miles from new, the top gear pinions failed, necessitating replacement under warranty of the mainshaft, top gear pinion and bearings."

[Ivan]

Hmmm, I guess the oil dam and capacity doesn't really make much difference according to that article...

Ivan

[ConnerVT]

I was thinking about this, and realized I misspoke (mistyped?):

Unfortunately, Suzuki never changed the "1200cc" stamp on the outside of the case, so it is possible that many 1974 and later bikes were run with only 1200cc of oil in the transmission.

I believe they did update the stamping from "1200cc" to "1400". What they left the same is the placement of the oil level screw, which could be removed while filling the transmission oil. Oil would come out when filled to 1200cc.

A handy item if you don't have something to measure your oil. Or wished to top off the transmission. But not much use if you need 1400cc in your bike.

[argo1974]

Today, after 6000 km, I replaced the 2L of Castrol MTX 75-140 transmission oil in the gear box of my T500K with new one.
Oil has been somewhat discolored probably from clutch plates wear, but I couldn't find any chips of metal at magnetic drain screw.
Great!