Bevel Gearshaft Repair

[legaleli]

Armed with my new torque wrenches (thank you GS Resources) and a repaired gearshaft (thank you GS Resources) last night I set about to install my gearshaft - and ran into a problem. I will take pictures tonight if I can't work it out - but I will start the thread now in the hopes that this happened to someone and they recognize the issue from my description.

Obviously, the bevel gearshaft is set in a housing. The housing is held into the crankcase by four bolts. A rubber o-ring seals the housing to the crankcase. The housing is spaced by metal shims. The tolerances of the housing and the crankcase are amazingly tight - so tight that I could not get the housing out of the crankcase until I was advised by Nessism to back off a pinch bolt that released some of the pressure.

When the housing came out of the crankcase I did not see how it happened... it just happened when I applied pressure and it happened to quickly for me to see.

So... last night I tried to put it back together and I can't. When I try to slide the housing into the crankcase I can't get a clear "straight in" perspective. The round outer edge of the bevel gearshaft housing comes in contact with a welded bumped out part of the frame of the bike near the swingarm holes (just below) so I have to angle the housing to not hit this bump of metal if I want to get it into the crankcase... but angling the housing to avoid this part of the frame as I try to slip the housing into the crankcase is impossible because the tolerances don't allow for it. Is it possible that the engine has shifted somehow in the frame because I have lifted the bike on a bike lift that is in contact with the crankcase?

Here are pics of my new tools and my repaired gearshaft:

 

[tkent02]

I don't know anything about your bevel gear questions, but those torque wrenches sure are pretty!

 

[rustybronco]

How about a nice shiny pic of the area in question?

 

[bwringer]

You have to loosen the engine mounts a bit -- enough to allow the engine to move a couple of mm.

 

[legaleli]

How about a nice shiny pic of the area in question?

This is the issue. The first pic is a straight on view. My finger is placed where the housing is rubbing against the frame (2). There is a pic from the front view as well (3). I also, at the bottom, have a pic of the engine mounts - which look fine (4). I think I can "force" it past the frame part that's in the way, but maybe grinding it off is a better option...

 

[TitanNeil]

I had to do this too recently, and somehow it went back together. I don't know EXACTLY how, as on my 1100 it too had the 'bump' that seemed to want to block the gear from going back in, but in it did go. It was a super-tight fit, but in the end it went in straight. A pry-bar on the frame (just gently, mind you!) might ease the process - and an extra set of hands would too.

 

[Steve]

Great timing on this. I am going to have to change those o-rings on my son's 850 when I get home, so I will be sure to watch very carefully as it comes apart to make sure I know how to put it back together.

.

 

[GregT]

I did this some years ago for a customer with an 1100. I ground the lump on the frame back to allow better access both to remove and reinstall.
I seem to remember it's a forging so there's plenty of meat you can remove without weakening anything. There may also be variation between one forged piece and another meaning some may not need grinding and others will.

Greg T

 

[Zooks]

When I did mine it went in with a fraction of a mm clearance. I didn't think it was going to go at first. I'd be inclined (as mentioned above) to loosen the engine in the frame and wedge a large screwdriver between the frame and engine to just lift it a few mm's.

Just make sure you remove the screwdriver and re-tighten the engine when you are done.

 

[legaleli]

Got it!

Got it!

Wow... I have SUCH a feeling of accomplishment right now. I managed to do it and all it took was a few hours of work and a few thousand hours of collective knowledge; again all due to GS Resources.

I will post pics and the method I used later today when d/l the pics from my phone (while drinking victory beer).

In short - I could not loosen the frame/engine bolts as they were REALLY tight and I didn't want to shear one off (I said REALLY tight).

I ended up grinding down a side of the bevel gearshaft housing a few MMs and it was enough to get the job done... there was a "bit" more to it... but that's the main thing.

Now I'm off to Canadian Tire to get some gear oil and some moly grease and back at the reassembly! Time to learn how to use a torque wrench... ok... I know how to use one of those!

 

[Nessism]

Good work! One thing regarding using torque wrenches: don't let hitting a number override your mechanical sensibilty. Sometimes the case screws can strip out at the stated torque, so if the bolt doesn't "feel" right near the limit, stop and don't try to get that last little bit out of it.

Good luck

 

[legaleli]

Good work! One thing regarding using torque wrenches: don't let hitting a number override your mechanical sensibilty. Sometimes the case screws can strip out at the stated torque, so if the bolt doesn't "feel" right near the limit, stop and don't try to get that last little bit out of it.

Good luck

Here are pics of the fix (my way). Because it was aluminum the gear housing was the easiest to grind. It still took some banging to get it in - but it worked.

One interesting issue was how to torque in the bolts holding the propeller shaft to the bevel gear end. I ended up tightening them as much as I could with a wrench and I made sure to clean the bolts and use "lock-tight ". I had the same issue with the fix for the actual gear shaft because I had no idea of the proper amount of torque to put on the bolt (the newly tapped bolt) so I just "gave'er" and made sure to use lock-tight. I'll know if something goes wrong!

The bike came back together pretty easily - I had one snafu - and this might happen to someone else., and I lost about an hour or so tearing the bike back down for no reason:

The bike was up on the bike lift being held up by the frame. The bike was in neutral and before I had put the "swing arm / propeller shaft cover" on I "tested" the rotation of the shaft and it was a perfectly smooth rotation - no binding or grinding and a nice firm feel to it.

I installed the swing arm and the rear wheel, but no shocks. The bike was still in neutral and I tried to rotate the rear tire and it would not move (the bike was suspended from the lift by the bottom of the frame). Something was binding and preventing the propeller shaft from turning, or something was wrong in the pumpkin - or so I thought. I pulled it all apart to find nothing wrong... then it struck me... the shocks were not installed... so the swing arm / rear wheel was extended so far as to cause the propeller shaft to bind against the housing. Basically the suspension was so far beyond its limits that there was a simple mechanical impossibility for the shaft to turn. Once I got the whole thing together WITH the shocks everything was perfect.

Here are the pics!

 

[Macguyver]

Done and Done. Good Job!

I too am going to replace some seals at the end of the riding season, and I have bookmarked this thread for fututre reference.

Thanks for posting pics!

 

[jhillier449]

Well done Eli. :clap::clap::clap:

 

[SqDancerLynn1]

Don't do as I did one time. I forgot to put one of the shims in place. So as to not remove every thing I cut the shim in 1/2 and put it in without any ill effects