Small oil leak.

I have some oil weeping out of the alternator (?) covering. It's not much but after a long ride it will leave a few drops on the floor. How much trouble is it to fix? Since it is so small is it even advisable to fix? 85 XJ700

 

all oil leaks should be fixed.
how much oil is inside that is the important question.
this oil will be all over your alternator after a while .
could leave you on the side of the road

 

I'd fix it. Small leaks turn into big leaks, especially where shaft seals are involved.
There is an oil seal on the alternator shaft, and an o-ring around the bearing retainer. It's a straightforwarrd job, with the most difficult step being seperating the alternator rotor from the alternator shaft.

 

Is there any link on the repair?

 

Might be, but I doubt it since it's covered in the service manual. I know the replacement of the seal and o-ring have been mentioned, but I don't have a link.

Here is what I wrote up for another fella this week.

You'll need a 3" (or so) long bolt ( 15mm x 1.0 or 16 mm x 1.0, I forget which, to be called the removal bolt), a socket to fit said bolt, ideally a short length of bar stock to set behind said bolt when in use (not absolutely necessary though), and a friend who has a foot you can borrow.

With the alternator cover off and the engine in gear have the owner of the borrowed foot press on the brake pedal.

Remove the holding bolt from the center of the alternator shaft.

Place the short length of bar stock into the hole if you have a peice of suitable diameter (again this is not absolutely necessary, but will help to prevent the working end of the bolt from mushrooming).

Thread the removal bolt into the alternator shaft (you will notice that there are two sets of threads; one for the holding bolt, and the smaller diameter is set for the removal bolt.

Turn the bolt until the alternator pops off (note, it is unlikely that the alternator will pop off easily. This is a taper fit and those are a bear to get unstuck).

Since the alternator did not pop off do the following while the removal bolt is still tight (do not overtighten the removal bolt or you risk stripping the threads and needing to have your alternator shaft reworked or replaced).

Use a 4 pound sledge and a block of hardwood to "gently whack" the head of the alternator removal bolt until the alternator pops off.
This last step takes patience and care as you are working near some easily broken aluminum engine cases. You may find that carefully applying heat to the area immediately surrounding the remoal bolt will help the taper fir to release. You will find that applying excessive heat to this area will melt the laquer on the alternator feild coils. DO not apply excessive heat to this area.

Installation is the reverse of removal, except that you will not need the removal bolt during installation. Resist the urge to lubricate the taper of the alternator shaft. A taper fit requires that both tapers be dry as they come in full contact with one another. Any lubricant will resist compression and either cause damage to whichever taper yields first, or allow the alternator to slip on the taper, shearing the key.
Do feel free to use a medium-strength threadlocking compound on the threads of the alternator retaining bolt.
Tighten the alternator retaining bolt to 39.8 ft lbs.

The alternator shaft seal is behind the bearing retainer, and that comes off once you remove the retaining screws (twist and pull. The o-ring holds it in place pretty well). The o-ring is on the outer diameter of the bearing retainer body.

 

Thanks. Sounds tricky, especially the taper fit. I had the same thing on a tractor and almost never got it off. By the way, you are right about it not being in the service manual--at least I can't find it. I'll contact Chacal about the seals.

 

It is covered in the service manual. It's part of the engine teardown procedure, so you won't find it on just one page.

 

Tabaka, whatever you do... take pictures and post! You did an awesome job with the fork seal replacement... While I haven't done the job yet, I just purchased the hex drives I need to get the job done... will be ordering the rebuild kit from Chacal soon.

 

If you can't get a hold of a friend and if your bike has the engine guards you can wedge a piece of 2×4 between the brake pedal and guard like this...


Gary H.

 

looks good. Thanks

 

The service manual shows the rotor removal bolt, which is easily attainable for several sources. It also shows a rotor removal attachment (part YM-04052), which I can't find anywhere, although Chacal has not yet responded. Anyone know what's it purpose and where to get one or make a substitute? Even Moton-Pro say that it is needed but apparently they don't have it either.

Also, how long is the rotor removal bolt.? I have a 16mm bolt but I don't know if it's long enough.

 

The rotor removal attachment isn't needed. IIRC it's to hold the rotor in place, which we are subsitiuting for by borrowing a foot.

The rotor removal bolt is about 3" long.

 

+1. The motion pro bolt...

Gary H.

 

The attachment is actually just a short dowel pin, it goes into the hole first, and allows the force from the end of the bolt (pictured above) to be transmitted to the center of concave end of alternator shaft....rather then having the bolt actually contact the shaft and possibly distort the threads as it is torqued down.

 

Thanks. I couldn't remember and don't have the FSM handy today.

 

So, it is smaller in diameter than the bolt, goes in first and acts as a push rode and centers on the middle of the concave end of the shaft? Chacal, did you receive my email about the seal, etc? Sent earlier today.

 

Tabaka, your understanding is exactly correct! Yes, we did get your e-mail and replied to it earlier this afternoon.......around noon.....did you not get it?

 

Sorry I just saw it. I'll contact you tomorrow.

 

Ok, got the write up form Chacal, and now I'm a little concerned about what is involved. I was under the impression that the seals were accessible after removing the rotor, but his write up seems to imply removing the torx screws which might require an impact driver and/or heat. I have an impact driver but I really don't like using it on aluminum and especially don't like using heat on aluminum. So, what exactly is the process after getting the rotor removed? He also mentioned an oil spray nozzle seal.

 

You do have to remove the torx screws that hold the bearing retainer. You should not need to use an impact driver to do so, but if you do you won't cause any damage. That part of the case is stout. The oil nozzle is easy to deal with. You can replace the oil nozzle o-ring, but I have yet to find one that really needs it.

 

Here is a good write up on changing the seals on a later model Yamaha. Probably not exactly like the XJ700, but close enough to make me feel better about the process. Very good pictures.

http://www.xjrider.com/viewtopic.php?t=2101

 

Nice find! Excellent write-up.

 

I have the stator off and two of the torx screws are loose. The one on the bottom right doesn't seem to want to come out. I tried a little heat with no success. My impact driver is 1/2 in drive so I'm on the way to get a 1/2 to 3/8 adaptor and will try that. By the way, the alternator cover and coils are also a little in the way for that screw and one of the mounting screws for the starter seems stuck an I don't want to take a chance on braking it. Any idea how to get the screw out if the impact driver doesn't work?

 

So far the impact driver is not doing any good. If anything, it is messing up the screw and it is beginning to slip when I try to turn it with the ratchet. Damn. all the other screw came out fine! Any suggestions other than to just keep hitting it with the impact driver?

 

What are you using as a heat source?

You should have both the rotor and the stator out of the alternator housing at this point.

 

Ok, I finally hit the screw hard enough to get it out. What I didn't know, and wasn't prepared for, was that when I pulled the plate off the shaft would come with it. I have now replaced the large o-ring and the o-ring on the oil spray nozzle. I assume that the shaft seal is simply pushed in from the outside. Is that correct? How is the best way to remove that seal? Finally, when I get that seal replaced, I hope all I have to do is line up the shaft and the gear inside and it all goes back in place easily.

 

I finally got it all back together and it seems to be working well. I have to admit to being a little worried when I first turned it over--hoping I wouldn't hear any grinding or strange noises. Fortunately, it started and runs well, and the alternator is operating as it should. While in retrospect it is a fairly straight forward repair, it can be a little intimidating for a first timer--it sure was for me--especially when the shaft came out and the sprocket was left loose in the housing. I took some pictures and will do a "how to" with pictures later. But, if you are going to remove the stator I highly recommend that you get the rotor removal attachment from Chacal. It's about $4.95 but it prevents any chance of damaging the shaft or mushrooming the removal tool bolt. The one he sent appears to be hardened metal with a polished chrome like covering that prevents any damage to the threads inside the shaft. Also, plan to replace the shaft seal, the large o-ring for the plate, and the very small o-ring for the oil spray nozzle. As it turns out, it was the oil spray nozzle o-ring that was leaking in my case. Thanks to everyone for your help. Although I've turned a lot of wrenches in my life, it's always good to have a really friendly source of knowledge and experience to draw on, not to mention an incredible source of part for these older bikes.

 

Just a follow up question or two.

The alternator shaft plate has 3 screw holes and small tabs, apparently to assist in positioning the plate over the screw holes. There are tabs on each side of one of the holes and only one on each of the other holes. When I reinstalled it I put the two tab hole over the oil spray nozzle on the lower left. I just noticed the picture in the service manual and the two tabs are at the top. I can't see why it matters, but if it does let me know.


The shaft seal and the large o-ring are good and tight but the oil spray nozzle seems to sit in place easily, i.e., not very tight, but held in by the shaft plate tab. Does that seem normal?

 

Orientation matters. There is an oil passage in that cover, and if it's not in the right spot no oil will flow to the bearing.

 

Thanks for letting me know. It will be fixed tonight. I just hope the shaft doesn't come out with it again.

 

Push on the shaft as you pull on the cover.

 

just a question but how does the oil nozzle come out of the case? mine is leaking from there

 

I'm assuming the case is not split. Use needle nose pliers to wiggle it out.

Gary H.

 

no case is not split was replacing shaft seal and noticed some oil around the nozzle i have a seal to change it