Changing final drive oil

So this is on my list of things to do, and I've been noticing all sorts of oblique references to things getting screwed up, or it being really difficult. Are these jokes, or is there some trick to these that's different from other 2-hole rear ends?

Is the issue just people ripping out the upper vent and filling it that high? Or is there something else I should know about?

 

No, the upper vent doesn't have to be removed. There should be a drain plug on the bottom of the final drive, and a filler about an inch below the axle nut.

Make sure you drive the bike so the oil is warmed up, put it on the centre stand and drain the oil. Then fill it until the oil level is level with the filler hole.


grz Thijs

 

Right, that's what I figured.


I'm just not sure what all the somewhat veiled references to secrets of it and stuff are about...

 

Bump.


Anything further? Anyone?

 

There's some different trick to the XJ and XS-11 FRONT hypoid housing- - or middle gear- - where you DON'T fill all the way.
And you don't remove the top vent on the regular XJ's

I sprayed some starting fluid in the housing, hoping to flush out any stray shavings, didn't really find anything. Let it dry for 15 minutes.
Wipe off the magnet, of course. Use anti-seize, that's about it.

 

Ok, thanks.

 

WOW so it seems to me the final drive holds a lot less gear oil than I would have thought, but of course I suppose as long as theres a couple inches of fluid in there bathing the gears it should still be able to bathe everything pretty well under use. I have this big ol' jug of gear oil and htought I'd be using at least half of it to fill my unit. From what came out when draining, even assuming I'm a little low, it doesent seem to be more than about 6oz of fluid.

BTW- anyone have any feeling on using 90wt oil instead of 80? Is my bike going to explode/burn up/ self destruct? It's what i have and I'd like to use it..

 

I think one of the jokes is that it's difficult to change the final drive oil on a 550 since they have a chain instead of shaft drive.

mikeg

 

According to my shop manual for my 82 XJ750 Seca the diff holds a whopping 0.18qts/200cc of 80/90wt GL4. Ain't much folks but I've never had a rear end problem (quite in the peanut gallery!) ever so it must work well.
Hucker, you should be safe.

 

Thanks Robert- appreciate the quick reply! I'll def let you all know if I have any issues, but I'm hoping all will be well. Ive had my XJ 650 for over a year and a half now and I ride it A LOT. (like over 15k miles at least since I got it) and I have never changed the gear oil. No performance issues except it is hard to find neutral when cold, I'm hoping by changing the gear oil I may get better lubrication and possibly it will shift to neutral easier. Maybe that's optimistic but it's all I can think of to do for now.

 

Changing the gear oil isn't going to do a thing for your shifting, your crankcase oil will effect that.
Good luck!

 

DOH! LOL well I change that fairly regularly so I guess I've probably got what I'm gonna get in that department! Sigh..