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Finally got round to stripping the model d to see why it keeps jumping out of gear and found considerable wear of the sliding dogs (spigots ends and socket faces) as I suspected, I have posted in the wanted section but I know its unlikely.

I assume the gear sets from later versions, with the better dogs, are not interchangeable?

Obviously the leading edges of the pins do take a battering, what would be the affect of grinding the ends flat, say removing 1-2mm to give a square edge again? Do they need the full length engagement.

I suppose the simple answer is what have you got to lose?

It may come down to you grinding the dogs square, or having a large pile of engine parts going rusty in the corner of you workshop.

If you don't get a response to your request, try RLC or get the grinder out Barry.

Thanks Martin

Just spoken with Howard C, his opinion is that any shortening of the pins will almost certainly have a negative impact, he did suggest maybe enlarging the holes but no guarantees, and that doesn't help the pin condition (they are pretty bad).

He is going to have a look to see if he has any old components in better condition than mine....fingers crossed. Apparently Casa are also looking at producing some gearbox components for the early models but info on this is a little sketchy at present.

Hard tig weld or laser weld is an option

If you could post some pictures of the gears you need I might have some NOS to suit. I presume they are the ones with round dogs & holes.
Cheers. Rob.

Hi Rob
Yes the early ones with the round dogs. I looked on the Italian ebay and found a NOS sliding 1st gear for sale it looks to have the same angles on the end of the pins as shown on mine, looking at the pins closer I can still see some of the original surface texture of the forging, the outer diameter of the pins look pretty good so I now think that one is in reasonable condition...the corresponding static 1st gear holes are quite worn but apparently that one can be turned round (although the profile of the face is different) I have tried this and the gears appear to lock together better.

The sliding 3rd gear with the pins is the worst one and quite worn specially the outer diameter and leading edges of the pins. The static one with the holes (that connect to the final drive torsion bar) is not too badly worn, some wear to the hole edges but probably ok.

Hope that all makes sense, anyway let me know what you have please




The wear on the dogs and holes doesn't really explain the jumping out of gear in 2nd though, the only thing I can think of is that I was having to over adjust the selector position to allow 1st to engage properly and in doing this 2nd is only partially engaging......anyone agree or have another opinion?

I'll have a look on Saturday to see what I have.

I have all four gears with the following tooth count.
Part 29 - 26 teeth
Part 30 - 32 or 33 teeth
Part 37 - 27 teeth
Part 38 - 34 teeth
They are all NOS with slight surface rust spotting.
PM me for price.
I hope this helps.
Rob.

Hi rob
Don't want to sidetrack this thread but I'm after a kickstart pinion and other parts to Finnish the d I got from ralf a couple of years ago !!,
Parts and part numbers for stuf wanted=
Pinion 110473 _6 ramp type
Washer 110477
Spring 110480
Shim 110479
All for 150d mk3
Hope you can help mate
Cheers Iain

Hi Iain
I'll get the parts book out and see what I've got.I have some pinions but will have to check which ones.

Hi rob
Will post picture out of the parts book if it helps.
Waddos got the book and its the small blue one and parts are on page 7.
Cheers Iain

Back to the original postings - before spending money on replacing the 'peg & socket' gears, I would take a very close look at the state of the six 'splines' on the mainshaft and those on the layshaft - plus the matching internal 'splines' on the loose gears. The ones visible on the layshaft seem to have a chamfer on one edge, rather than having a square section. I'm not that familiar with the early gearboxes, but a couple of years ago I had a problem with a Mk3 Ld which kept jumping out of gear. Replacing the loose gears didn't cure it, and in the end I had to swap out the mainshaft and layshaft to fix the problem, which was due to excessive wear on the ends of the 'splines'. TBH, a previous owner must have had a problem, as attempts had been made to 'neaten up' the ends of the splines with an angle grinder.
If you discover the mainshaft is U/S, I'd be tempted to swap the entire mainshaft, layshaft & gearset for the later 3 dog or 5 dog type. OK, so it's no longer strictly authentic, but at least the scooter would be usable!

Just as an afterthought - is everything working properly in the selector box? ( - assuming it's the early type with the spring-loaded roller.)

Hi Iain. I thought I might be able to help you but I can't put my hands on the pinions I thought I had. I don't have the other parts either. Sorry,
Rob.

Hi Steve.
I have looked at the new shafts I have and the early ones have the chamfered splines and the later ones square. I could be wrong but Barry's part doesn't look too worn compared to the new ones.
Thanks.
Rob.

I agree I have examined the shaft that is out of the engine and some of the original tooling marks are still visible , thanks for raising the point though.
Barry

Hi rob
Thanks for looking mate, I'll sort it.

Hi ricey - I think I've found the parts you need - please PM me!

Thanks Steve you have pm
Cheers iain

Just to feedback, the NOS gears have been fitted and for the limited try out the gearbox performs perfectly, and for the first time the d125 is a real joy to ride.. can't wait till the warmer months now.

thanks all for you input