GS1100G - Shaft Drive Lubicration Leak

[williamcryan]

I have a slight lube leak near the shaft and transmission point. I get a light spray onto the left side of my rear tire and it gives me some unease on left turns on twisty roads, especially if it would be wet.

I don't know enough about the seals that seem to need replacing or how complicated or involved the fix would be. I have some garage availability and if it is an expensive seal but labor intensive, I may consider fixing it myself.

Are there any members out there that has some experience with this problem and can give me some information on how they fixed the leak and how involved the fix was?

I would appreciate any help. The bike is great.

[SqDancerLynn1]

First is it engine Oil or gear oil ??? Have you verified the point of the leak? If it is the flange ?? The flange that the driveshaft bolts too does have a replacable seal & O ring, but needs to be removed for service. You Must remove the swingarm to gain access to the secondary gear for removal. That means, shocks, brake calaper, wheel & rear diff/ swingarm assembly. Another more likley spot it may be leaking from is the starter cavity - Bad O ring on starter & it leaks thru the mystery hole drains under the shifter on bottom of crankcase. Change the starter O ring first !!!

[psyguy]

consider getting the service manual

as lynn says, first confirm what the leak really is - wash everything off and then check every so often to see where the leak is comming from
if it is indeed the secondary gears oil, there is a couple of bolts - the drain bolt and the oil level inspection bolt - that may need tightening

btw, your oil level may be too high, so check that

other than that, bevel gears have replaceable o-rings and bolts that have to be torqued down properly

[Zooks]

Ditto ^ ^ ^ - It's fairly easy to pull the back end apart if you take it step by step (remember the hare & tortoise). The O rings are easy enough to replace.


BTW - if it's gear oil you'll know by the funky smell (man, that stuff stinks).

[knotzilla]

The seal here in Canada costs almost $80 along with the O ring another $15. You might also need a special seal tool to install the seal. You might just as well but a complete rear end drive on Ebay, Ted

[Steve]

You might just as well but [buy?] a complete rear end drive on Ebay, Ted

Spare rear ends are always nice, but if the leak is at the engine, it won't do anything to fix that.


.

[knotzilla]

If the oil is on the rear tire the odds are it's leaking from the rear drive unit. It's no big deal to remove the tire and take a look, Ted

[Steve]

If the oil is on the rear tire the odds are it's leaking from the rear drive unit. It's no big deal to remove the tire and take a look, Ted

From the original post:

I have a slight lube leak near the shaft and transmission point. I get a light spray onto the left side of my rear tire and it gives me some unease on left turns on twisty roads, ...

It sounds like he has found the general location of the leak, but does not have it pin-pointed yet. I would think that if the final drive were the source, all of the leakage would be on the sidewall of the tire. That should not cause any handling problems. If, however, the leak is at the engine as he suspects, it could be blowing back onto the tread. That would even make me nervous.

.

[knotzilla]

Maybe the engine breather hose to the airbox is kinked or the vents in the airbox are plugged with rust causing the inside of the engine to build up with pressure. I had several minor engine oil leaks but found that the problem was where the breather hose entered the airbox was plugged with rust. After a few mods, all the oil leaks stopped, Ted

[williamcryan]

Thanks for the tips

I'll research my lube leak farther, thanks to the tips you guys have provided. It is great to have a site like this for GS owners, especially as the 82 bikes are going into the vintage classification and it is hard and expensive to find mechanics to work on them.
Based on what I have observed, the leak is from gear oil. I need to add gear oil frequently and I remove the overflow screw fitting and add until gear oil comes out with the bike on it's center stand. The leak seems to come from around the gear shift area.
I'll keep you posted and I generally agree that I have to drop the shaft and check all drive components.

[psyguy]

The leak seems to come from around the gear shift area.

so, possibly the side bevel gear o'ring may be the culprit - this oring you can replace by loosening the case bolts around that area, then the four bolts holding the bevel gear, and then pry it out. not difficult

[Matchless]

A very possible leak could be the oil seal on the gear change lever, easy to replace, just buy a 22 x 12 x 7 mm (SM12227) oil seal drom your local bearing and seal supplier, while you are at it get two and also replace the one under the clutch arm, cheaper than a beer!

If it is the rear oil seal in the secondary drive case you will find a lot of oil inside the rubber boot and that seal can also be bought from any bearing and seal suppliers, just get a 35 x 52 x 7 mm (SM35527) seal, as stated earlier by other posters, a bit more work to fit, but not difficult.
Good luck

[bwringer]

A very possible leak could be the oil seal on the gear change lever, easy to replace, just buy a 22 x 12 x 7 mm (SM12227) oil seal drom your local bearing and seal supplier, while you are at it get two and also replace the one under the clutch arm, cheaper than a beer!

This seal would leak engine oil, not gear oil.



If you're losing gear oil from the engine end, then it's either the seal around the output shaft or one of the o-rings around one of the bevel gear units.

None of these are at all prone to failure, so I suspect that there's a problem with one of the bearings on the output bevel gear causing the shaft to wallow around, or that the output flange shaft has broken at the retaining nut. The bike will still go, since the flange shaft is splined to the output shaft, but it will flop around quite a bit and eventually leak.

Peel the u-joint boot back and poke and pry at the metal thingamajigs in there with a screwdriver. Excess movement will be easy to detect.

You can (just barely) remove and replace the output bevel gear unit with the engine in the frame after removing the swingarm and loosening the engine mount bolts.




Also, here in the metrically retarded USA it's much easier to simply order seals from Suzuki. It's nearly impossible to specify and order metric seals -- even metric seals are usually repackaged and labeled in 1/64" units. For example, a 50mm OD seal is usually labeled 1-31/32". Drives me NUTS!

You can certainly get metric seals -- we have Toyotas and Hondas too, and even US cars have been completely metric for 20 years or more -- but it's very difficult for the consumer to convert the measurements and communicate what he needs to the average supplier.


A couple of saving graces:

http://www.metric-seals.com/

Yes, there is an entire company that exists simply because most suppliers in the USA are too stupid to use proper metric measurements. They're also located about 15 miles from my house, and have bailed me and many a vintage motorcyclist out of a jam.

http://www.mcmaster.com

And, of course, there's good old McMaster-Carr. They have a few metric seals. Very few.

Whoopsie, I slipped into a rant there. Sorry...

[Matchless]

This seal would leak engine oil, not gear oil.

Sorry, unobservant, missed that last post that said you were definitely losing gear oil!!