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Gearbox recall repair


guido

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So, I have started to rebuild my green V11. It has not yet had the gearbox up-grade done, so out with the engine and box. Box is now in pieces, and I have re-placed the two shift rings. The originals look fine, the new ones look much the same, but have a cut groove around the circumference. Are the originals cast and the replacement milled?

The job, so far, has been easier than I feared.

Just a couple of things. The sixth gear has been rubbing against the fixed sliding sleeve on the lower secondary shaft. See picture. You can just notice the bluing at the top of the splines. It looks to me as if the splines are not exactly the same height, and 3 or four have been in close contact, to the point where they have blued, and and started to fuse with the gear.

I have filed the rought patches and smoothed it with fine paper, I hope that will do.

Just before I had the accident, I felt a roughness in the bike, I wonder, can this explain it?

It seems too minor to me to be able to cause a significant force on the back wheel,but I am no expert on gearboxes, yet!

Secondly, there are two extra items in the factory re-call pack, apart from the two sliding rings, namely part of a flexible coupling and another shim (for the internal cushion drive) Both look absolutely identical to the items already there.

They are a bit trickier to get at, because you have to compress a stack of special springs to be able to get at them, and all my efforts to improvise on that front, so far, have yelded no success. I wonder, is it necessary to replace them ( I have never noticed these items being mentioned before) and, are they supposed to be changed because of another design, in which case I already seem to have these items installed, or are they also prone to failure of disintegrating6Y200132.jpg

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Guest Gary Cheek

The original parts were sintered, AKA "powdered" metal. The replacements are billet parts. I don't beat mine up and wish I had never let them touch the box. Went from silky smooth to harsh and nasty, sticky POS. First chance I get it is coming apart and getting a good massaging.

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Just a couple of things. The sixth gear has been rubbing against the fixed sliding sleeve on the lower secondary shaft. See picture. You can just notice the bluing at the top of the splines. It looks to me as if the splines are not exactly the same height, and 3 or four have been in close contact, to the point where they have blued, and and started to fuse with the gear.

I have filed the rought patches and smoothed it with fine paper, I hope that will do.

Just before I had the accident, I felt a roughness in the bike, I wonder, can this explain it?

It seems too minor to me to be able to cause a significant force on the back wheel,but I am no expert on gearboxes, yet!

 

That would bother me, a lot. The gears, etc., are inundated in oil which has additives to help it work in high load conditions. For something to break down that lubrication to the point where blueing has occured means that _something_ is seriously wrong. You absolutely _must_ be sure that all dimensions, clearances and suchlike are correct before you use the box again. I would not use the box until I was sure of the reason for this.

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That would bother me, a lot. The gears, etc., are inundated in oil which has additives to help it work in high load conditions. For something to break down that lubrication to the point where blueing has occured means that _something_ is seriously wrong. You absolutely _must_ be sure that all dimensions, clearances and suchlike are correct before you use the box again. I would not use the box until I was sure of the reason for this.

Well, it has started to bother me, a lot. I can't find a good reason for what I see. The issue is more than bluing as there has been fusion and pick-up (welding). The box has got 1100 km. It is brand new. There are no other signs of wear, what so ever. It was full of oil, it was clean and everything looks fine, except for four tops of the flanges. The rest of the flanges are perfect. The gear is supposed to rotate here, and I can't quite phatom what could possibly cause only some of the flanges to be affected. The bearings are fine, the shaft can't? be bent, and in any case it is brand new.

I had a feeling of roughness, or vibration, just before I crashed the bike. I wonder if this can explain what happened.

I have given the shaft, complete, to the Guzzi importer, he will (he says) try and get a reply from Italy, when he is going there in about a week.

Should be interesting!

I will not put the box together again before I can explain what has gone wrong. One experience of this nature in a lifetime is enough.

On another track, I have done the mods to the shiftspring arm, the boss was 16.2, now it has been filed to about 14.8mm, and the edge of the support sanded nice and round. Thanks to Belfast and dlaing for good info on this subject and to the others in the forum.

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  • 1 month later...
  • 1 year later...
Any news on this?

Just to fill you in.

I took the whole lower secondary shaft to the Guzzi importer here, for them to take it to the factory. He promptly lost it!

I have since been in contact with Moto Guzzi in Italy, (what a nightmare, they responded only when I started phoning, ignoring my repeated e-mails and faxes) They seem to be quite understanding so far. Maybe it helped when they realised that I am quite devoted to the make.

The local importer in the meanwhile has given up on Aprillia and Guzzi. Aprillia has been taken up by Thriumph/Kawasaki, but Guzzi is, unfortunately, dead here !!sigh!!.

We have come to the arrangement that the box goes to an Aprillia dealer here, and they will then interact with Moto Guzzi in Italy.

The box is now with them, and they must take it further.

If you prompt me later, I shall give you all the info as it becomes available.

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