83 850L Oil Leak from Drive Shaft Boot

[Sniper]

Ok, I couldn't find this anywhere else, so I'm asking for a little help before I order stuff and start taking things apart!
My 850L has an oil leak coming from the boot around the front end of the shaft where it connects to the transmision. I found a hole in the boot, so it obviously needs to be replaced, but I'm wondering if there is an oil seal or seals or o-rings on the drive shaft that I need to replace also, and if so I'm not sure where to find it/them on the bikebandit diagrams. If there are some other o-rings I should replace while I have her apart, that would be helpful too.

Also, is there anything I should look out for and or mark or take pictures of to make sure I line things back up correctly. I've never taken off the rear wheel of a shaftie before, so I'm a little concerned about the pitfalls of getting the thing apart and back together the way it should be!

If I can get this oil leak taken care of she'll be back into rare form [-o<(after a carb cleaning, replacing the premuffler, and a tac drive gear seal replacement which are all in the process as I await parts )

[Sniper]

Also wondering what is the best way to clean all the oil off the bike. In addition to the boot leak, I also had a leaking tac dive gear (I thought the dealership fixed the leak prior to me buying the bike by replacing the valve cover gasket), so I have oil all over the front of the engine and on the frame behind the shaft boot. Any suggestions would be great!

[seuadr]

on the metal, unless it's a painted surface, carb cleaner should do the trick cheap and easy. if you have a painted surface, probably your best bet is some engine foaming degreaser, and some quality time at the car wash or with a power washer if it's grimey on the engine, or just a power washer should do the trick, honestly. careful about getting the carbs wet if you have pods, though, same for the coils under the tank.

[bwringer]

Are you sure it's coming from inside the boot? This boot commonly gets covered in mung from the airbox drain tube.

The rear drive gears are also sealed, so the drive shaft and u-joint run dry. There shouldn't be any oil in there.

What's under there is the final drive gear assembly. There's an o-ring around the gear assembly, and a seal around the drive flange shaft. The gear assembly can be removed, but you have to unmount the engine and move it to the side -- it can be done, and is straightforward, but probably not a good starting point if you've never removed the rear wheel.

However, it would be VERY unusual for these to start leaking without a good reason.

Can you determine what exactly is leaking? Gear oil has a distinctive icky smell -- is it, in fact, gear oil?

Mung from the airbox smells sort of like exhaust and old gasoline.


Finally, have you seen this for the tach cable seals?

http://bwringer.com/gs/tachcableseals.html

[Sniper]

I've got the carbs and airbox off right now (doing a good cleaning of the carbs to replace all the o-rings and gaskets due to it was leaking a little gas and they needed a good cleaning anyhow), so I'll clean the gunk off her tonight the best I can to see if anything leaks out near the boot while I work on the carbs and muffler.
If I pull the boot back (not sure if I can or not, it's in there pretty tight against the frame) would I be able to see something if it where leaking from the gear assembly area?

And I have seen the tach cable seals page. I actually posted a thread asking about that one that you replied to (a million thanks by the way), and replaced the seals, but it still leaks just a little bit, so I'm going to replace the drive gear (as it does have an ever so slight goove) and see if that fixes the problem!

[BassCliff]

Hey howdy hey

Hi Mr. Sniper,

I'm sorry that I can't remember if I've given you my mega-welcome yet. I must run off to work so if you don't mind, take a look at the online version of the mega-welcome and stop by my little BikeCliff website for all kinds of goodies that I've been collecting regarding the GS850 and other models.

Thanks for joining us and keep us informed of your progress.


Thank you for your indulgence,

BassCliff

[bwringer]

Yes, you can peel and push the boot back and take a look in there -- it's not an oil seal or anything. The boot is only there to keep water and stuff out.

There's enough room to get a couple of fingers in there. If you rotate the rear wheel (after pulling your fingers out of the way), you can see the u-joint spin and the four bolts that hold the driveshaft to the flange.

The u-joint is permanently sealed, but it's extremely rare for these to ever have a problem.

[psyguy]

this is the schematic you want to take a look at

http://www.bikebandit.com/houseofmotorcycles/showschematic/m6117sch239828

your suspect is #14 (or possibly #15)
but as said, this is very unlikely to be your problem - thats probably why you couldnt find any posts on this topic

i'd clean the whole bike and put new final drive oil in, ride for a while and take an ocassional peek under the boot to see if its wet or dry

(dont give yourself a headache of replacing this o ring for nothing!)

[Sniper]

Good advice guys, I'll clean her off the best I can and see what I can see. I'll let you know how it turns out [-o<.
Still waiting on my tach and carb parts. Stupid UPS delivered to my house at 1pm 3 times (I was at work of course), so now I have to go down to the UPS Store to pick them up. Going there tonight, and hoping I'll have time to put her back together this weekend!
I'll keep you posted.

[SqDancerLynn1]

If you find you need to replace the seal/O ring Just remove the swing arm & you should be able to get to it. I had mine out on my 850 & didn't have to move the engine. They do fit in tight.

[Zooks]

Agreed, I just pulled my 'new' 1100 apart tonight and didn't have to move the engine. It literally misses by about 1mm though. I would presume that the 850 and 1100 are the same in that regard. As you pull it out you can angle it slightly and it just clears the frame.

[bwringer]

Agreed, I just pulled my 'new' 1100 apart tonight and didn't have to move the engine. It literally misses by about 1mm though. I would presume that the 850 and 1100 are the same in that regard. As you pull it out you can angle it slightly and it just clears the frame.

Good to know! I've only pulled these out after removing the engine entirely for other reasons.

Still, chances are the OP won't need to do this.

[Sniper]

Well, the weekend came and went, and I didn't do much on the bike. I did however pull to boot back, and........ the worst thing I could have hoped not to happen at this point happened. As I pulled the boot back about two tablespoons of gear oil drained onto my concrete floor! So I assume I have a seal problem and will most likely need to remove the shaft to figure this mess out. What is the likelyhood that this will be terminal for the shaft or transmission? I'm kinda worried that my bike (that I now know I slightly overpaid for) is terminally ill (at least for me, due to my lack of knowlege about the transmission).
I'm also wondering what might have caused this, however I may find out more about that if I pull her apart.

[Zooks]

You worry too much. There is a reason that these bikes are called 'bullet proof'. If it was running okay before you pull the shaft out what makes you think it will be worse after you put it back in?

Pull the wheel, swing arm and shaft, replace the o-ring, grease all of the components and bearings whilst you have the back end apart and put it back together.

Don't forget to bleed your rear brakes when it goes back together.

[psyguy]

thats not so good news - lots of work to get to that one o ring
before pulling things appart i d double check the tightness of the crankcase bolts at the back first
if they re not tight enough that may be contributing to the problem
the o ring in question is not under much stress (mechanical or temperature or oil pressure) so its unusuall that it d go bad just like that