‘83 GS650GL Drive Shaft Oil Seal Replacement – How Hard?

[Guest]

Well, I think my “easy” restoration project just got harder.

It looks like I have an oil leak inside the big rubber boot that covers the drive shaft where it attaches to the back of the engine gear case.

I looked at the Suzuki parts microfiche and it shows that there is an oil seal on the back of the engine where the drive shaft comes out of it. I guess that’s the leak source. I haven’t started disassembly yet to check it out, but I have some questions before I start:

Has anyone replaced that oil seal on their GS before?

If so, does the entire swing arm have to be removed to replace it? (It sure looks like it has to be removed! )

When you remove the swing arm, do the guts of the drive shaft itself come out with the swing arm, or does all or part of the actual drive shaft assembly just hang there in mid-air still attached to the engine/gear case?

I guess what I’m asking is whether or not there is a split of some short in the middle of the drive shaft assembly that allows you to remove the swing arm easily without having to disconnect the drive shaft assembly from the back of the engine/gear case first.

And, once you get that all disassembled, can you install the oil seal without any engine or gear case disassembly?

And, on a hopeful note, IF I find no oil INSIDE of the rubber boot, where else could that oil be leaking from and getting all over the bottom of that boot and the back/bottom of the engine?

I sure would appreciate any advice from members who have replaced this oil seal before. It will help me to not make some bone head mistake!

Thanks.

[Steve]

Swing arm removal is actually rather easy.

Remove the wheel and shocks. Remove the pivots at the front, slide the arm rearward, off the shaft. If you want to reduce a bit of weight, remove the final drive from the swing arm before removing the swing arm pivots.

I have not had to change the seal, so can't advise what is necessary there.

.

[bbjumper]

Having oil back there is one problem, however make sure the oil isn't coming from the transmission past the oil seals into the secondary drive and then out the prop shaft. The seals between the transmission and the secondary drive failed on mine and it required a complete tear down to dry things up.

Water gets down there, PM me and I'll give you the whole story, takes out the seals and then you got a real PITA.

I did mine last May and now have around 5k on the bike, runs like new and I don't need to add any oil between changes..

Good luck

[WingMan71]

... slide the arm rearward, off the shaft.

So, I'm correct in assuming that there is some sort of splined sleeve on it that lets the drive shaft itself just pull out of the front of the swing arm still attached to the back of the engine, correct?

Thanks for your help!

[WingMan71]

... however make sure the oil isn't coming from the transmission past the oil seals into the secondary drive and then out the prop shaft.

bbjumper,

According to my factory service manual, the GS650 engine does not have a separate sump for the secondary drive and shares it's oil with the main engine sump. Maintenance instructions say nothing about draining and refilling the secondary drive oil separately.

Does that sound right?

PS) I'm really hoping I get into this and find something other than the drive shaft seal that is the source of the leak.

I also have a bunch of oil all along a fat cable (electrical?) of some sort that runs along the bottom right side of the oil pan on the bottom of the engine. What the heck does that cable connect to?

Thanks for your help!

[bbjumper]

bbjumper,

According to my factory service manual, the GS650 engine does not have a separate sump for the secondary drive and shares it's oil with the main engine sump. Maintenance instructions say nothing about draining and refilling the secondary drive oil separately.

Does that sound right?

PS) I'm really hoping I get into this and find something other than the drive shaft seal that is the source of the leak.

I also have a bunch of oil all along a fat cable (electrical?) of some sort that runs along the bottom right side of the oil pan on the bottom of the engine. What the heck does that cable connect to?

Thanks for your help!

My Bad WingMan, didn't see you had a 650 and yes you are correct. all the oil is in one place on the 650

[tom203]

As Steve said, remove swingarm- splined prop shaft should slide out of swingarm housing (Disclaimer, I haven't done it and hoping not to!). Then looks like remove bolts from u-joint and seperate shaft from secondary drive housing. Mark orientation of housing on crankcase (it was likely fitted carefully)- I imagine you'll have to loosen some of bolts holding crankcase halves together in drive housing area, so you can extract housing as its likely pinched in. What fun! make sure that this is leak source.

That "fat cable" sounds like wires from signal generator and oil switch

[WingMan71]

... What fun! make sure that this is leak source.

That "fat cable" sounds like wires from signal generator and oil switch

Tom,

Thanks! Yes, I'm going to look for all possible other sources for this leak before I even think about taking the swing arm off! I'm hoping it's something else! But the bottom of that drive shaft boot is sure full of oil.

So... if that fat cable comes from an oil switch, would a leak at that oil switch find it's way to the back of the oil pan and the drive shaft boot area at the back of the engine? (He says, hopefully!) And, just exactly where is that oil switch located?

[tom203]

Since you said...." I have an oil leak inside the big rubber boot that covers the drive shaft where it attaches to the back of the engine "... I'd say you got fun ahead. If oil switch leaked, oil would fill signal generator area and run out of cover right there.

[WingMan71]

Since you said...." I have an oil leak inside the big rubber boot that covers the drive shaft where it attaches to the back of the engine "... I'd say you got fun ahead.

Tom,

Actually, I haven't taken anything apart yet. So, I only know for sure that I have oil all over the bottom of the big rubber boot that covers the drive shaft where it exits the gear case.

I don't know if there is oil INSIDE of the rubber boot. I'm gonna take things apart this weekend and find out!

Still hoping for the best...

[recycled64]

Before you take anything apart, check to see that the 'other' drain plug, (found up underneath the left rear of the engine, 21mm head) isn't the source of your leakage/seepage/weepage. (actual factory warranty qualification descriptions by BMW, years ago.) That drain plug is right in front of the boot.

[WingMan71]

Before you take anything apart, check to see that the 'other' drain plug, (found up underneath the left rear of the engine, 21mm head) isn't the source of your leakage/seepage/weepage. (actual factory warranty qualification descriptions by BMW, years ago.) That drain plug is right in front of the boot.

Thanks very much!

I'll be sure to check that first.

Questions:
What exactly is this "other" drain plug for? Is it actually in the oil pan just forward of the shaft drive boot?

I'll look for it tonight when I get home from work, but I'm kinda curious now.

[tom203]

That "other drain plug" drains the small quantity of oil that hangs out in secondary drive cavity. When you peel back the U-joint boot , you'll know for sure if oil leaking into it (small quantity is no problem) - maybe you'll get lucky, as other places are better sources of oil leakage.

[Steve]

The "other" drain plug is not in the oil pan.

If you get low on the left side of the bike and look up, just ahead of the shifter shaft, you will see the plug.

Here is a cut-and-paste from the factory manual:


.

[WingMan71]

Tom203,

Thanks! I hope I get lucky too!

Steve,

Well... color me embarrassed! (Didn't know that second drain plug was on this bike.)

Just got her 4 days ago and have only had a cursory look around it to date. This weekend starts the real disassembly.

Thanks all for your help.