Final drive vent?

[TomRodgers]

Hey all... just curious as to the 'plug' at the top of the final drive. on the 3 bikes, there are two different styles....one is a big round cover, the other is a smaller black almost cone shaped. The third bike ('Sunshine), it is snapped off.

Question is.....how important is this thing?

[Guy_b_g]

You don't want moisture in there..and you need to vent the pressure as it heats up or you'll get leaks past the seals..kinda important I'd say.

[TomRodgers]

I kinda figured that.....

the 'cap' is snapped off, but the actual 'plug' is still there. a hole about the size of a pencil lead is at the very top.i thought about putting a dab of silicone on the sides of the cap and setting the thing back on just to keep the moisture out, but still allow the air pressure out.

i dont ride in the rain if at all possible, but i also dont like foreign matter, no matter how small, to get into areas that dont like anything but lube!!!

[WMarshy]

Can you epoxy the broken part back on? Assuming you still have it...

[Guy_b_g]

There are a few threads that deal with the vent and fixes for it...try a search for "final drive vent"

[DGXSER]

Realistically, it is pretty easy to find spare XS1100 Final drives. Since alot of us switch out to the 750/850 fds, they are pretty easy to find. I know I have one I'd be willing to part with.

[Erik the Red]

slight change to topic

So, rather than start up a new thread, I figured I'd tack on to this one... This winter I rebuilt my spare final drive, since mine broke splines in the fall. I didn't pay attention to the vent, but now I'm painfully aware that its cap is broken off, and is also important.

Are there opinions on the best way to remove a good one from a housing? I know John took a cutting wheel to one, and said he had some success with that approach. I think I read somewhere else that heating the housing up with a torch loosened up the vent enough to pull it out without de-capping it.

How deep is the vent into the housing? And can anyone give some (detailed?) pointers on getting out a good vent to replace the one without a cap. OR, would it be better to just leave the vent in, and just epoxy a cap to it? (I'm tempted to do that, but I don't want to destroy a complete vent if that's not the best way to go)

Any and all advice is appreciated... Thanks.

-Erik

[DGXSER]

Honestly, the best advice I can give is for you to consider buying a 750/850 drive to replace that one. It will certainly be less headache. AND you get the benefit of the 750/850 FD. JAT.

[crazy steve]

So, rather than start up a new thread, I figured I'd tack on to this one... This winter I rebuilt my spare final drive, since mine broke splines in the fall. I didn't pay attention to the vent, but now I'm painfully aware that its cap is broken off, and is also important.

Are there opinions on the best way to remove a good one from a housing? I know John took a cutting wheel to one, and said he had some success with that approach. I think I read somewhere else that heating the housing up with a torch loosened up the vent enough to pull it out without de-capping it.

How deep is the vent into the housing? And can anyone give some (detailed?) pointers on getting out a good vent to replace the one without a cap. OR, would it be better to just leave the vent in, and just epoxy a cap to it? (I'm tempted to do that, but I don't want to destroy a complete vent if that's not the best way to go)

Any and all advice is appreciated... Thanks.

-Erik

I ran into this problem when I polished my FD housing. I tried to remove the cap so I could polish behind it and broke off the spot weld that holds it on. My solution? I brazed a 6/32 nut to the top of the taper, then drilled/tapped it for a 8/32 screw. In my case, I made a new cap out of aluminum and attached it with a counter-sunk screw, but you could reuse the existing one. Getting the old vent out would be a real PITA as it's pressed in...

'78E original owner

[Erik the Red]

Thanks for the replies. Well shoot, I hadn't considered the 750/850 final, and went ahead and replaced the seals on this one, so I'm going to stick with that one for a while. Next time I'll remember that... Especially since I picked up an XJ750 parts bike last week that I'll be taking apart, and now have that final.

Unless someone else can shed some more light on it for me, I'll probably just end up breaking the cap off the old final and epoxying it to the vent cone.

[DGXSER]

Sorry to say, I believe the XJ750 is NOT a swap in for the XS1100 Final drive. the XS750 or XS850 is.

[Erik the Red]

Sorry to say, I believe the XJ750 is NOT a swap in for the XS1100 Final drive. the XS750 or XS850 is.

Well, that's good to know. I just made a quick assupmtion. I guess I'll try to sell it to the XJbikes crowd, too, then.