Final driven flange in rear wheel came apart

[admin]

I got a call this morning from a member of this board who had a breakdown. Seems all the nuts had fallen off the final driven flange fingers and it made a bit of a mess of the plastic covers back there as well as making noise while he's driving. He was thinking about carrying on without the nuts in place but I suggested that he obtain some nuts and washers and some blue Loctite so that he can secure what's left and try to make it home as gently as possible.

This is a first for me. Have any of you heard of this happening before?
I beleive that he is going to need a replacement driven flange when he gets home due to the fact that the loose nuts have allowed the pins to distort the holes so if any of you has a line on a driven flange for a GL1200 let's hear from you please.

I don't want to publish the guy's name until I have his permission but once he's home I'll get him to come on and let us know what's happening.

[exavid]

He will be very lucky if the isolators in the wheel are still okay. If you notice the Honda manual says not to undo the nuts on the driven flange. I would expect the flange is also shot as you said the holes are most likely wallowed out. They are a precision fit and won't hold together if they aren't a perfect fit.

I do agree that putting nuts and washers on the pins might hold the flange together for a run home but it could get pretty nasty if one of them came loose and jammed the rear wheel at road speed.

[admin]

He's going to have to do a complete teardown and inspection when he gets home to determine the full extent of the damage. I've never heard of such a thing happening before.

[Jazzwing]

The bike in question is mine; I was holding off making this post until I was able to make a thorough inspection.

First of all I would like to publicly thank Vic for talking me through this event; he gave me the confidence to move ahead with repairs with some insights of what to look for. And thanks to the folks at the Travelodge on Hurontario St. in Brampton, Ont. for letting me do the repairs in their parking lot and allowing me to get cleaned up well after checkout time!

After replacing all 6 nuts with nuts I picked up at Canadian Tire (M10 x 1.25) with a good dose of blue threadlocker on each stud, I made sure that there was no distortion in the holes where the driven flange is inserted (dampers). There was no slop at all in the flange and no visible damage or wear to the dampers. The threads on the studs had absolutely no damage, the studs were straight and true with no wobble, and the splines on the flange were in perfect shape. Since I didn't get the wheel completely out and I didn't have good light, I couldn't see everything in the final drive unit, but a 'feel' inspection of the splines indicated that there was no damage. I did notice that the screw boss for the screw that holds the plastic dust cover in place was broken out.

I got the wheel reinstalled and drove from the Toronto area to Sarnia, Ont. on Tuesday, then Sarnia to Traverse City, MI on Wednesday morning. The only trouble I ran into was not having the right change in my hand at the 'coin only' tollbooth on the bridge. (The fare is different going into the US than into Canada). The bike performed perfectly at freeway speeds the entire trip. (Note: I did a lot of testing at low speeds before getting on the freeways - I'm not completely nuts!)

I just finished getting the rear wheel off to do a more thorough inspection. The nuts I installed haven't budged. There is some surface damage (knicks & scrapes) to the metal casing of the final drive from the nuts bouncing around in there, plus that broken screw boss. The splines in the final drive unit are in perfect shape. It seems that the only damage done was some surface damage to metal casings.

The most peculiar thing I found was the number on the flange. After looking up part numbers, the '84-'85 part number include the code MG9 as do many of the other major parts on the bike. My flange has ML8 molded into it, which is a number used for '86-'87's. Apparently they're interchangeable, unless the wheel is also '86-87. Does that mean the drive unit and wheel may have been changed at some point in this bike's life? This is my third year with the bike and I don't know much about it's life prior to my ownership.

To conclude, I'm going to reinstall the wheel and get it back on the road. I feel confident that I won't have a major problem for a few months of riding, although I will be inspecting it constantly. In the meantime, I will be on the lookout for a replacement rear wheel, flange and final drive to swap out this fall or sooner depending on when the right stuff becomes available. Looks like we have another topic for informal talk at the August gathering!

Mike Hunter

[myplace 46]

sounds like you got lucky Mike.could have been a lot worse!

[admin]

I was just thrilled to hear that you made it home safe and sound Mike. I couldn't believe the nature of your problem. Those nuts just don't come loose, yet all of yours fell off. Anyway, it's great that you were able to get it fixed and carry on. Sure makes for an interesting memory.

It would be interesting to find out about those part numbers. Maybe your bike is a late 85 with 86 parts.