Head Repair springer 250 bevel drive pass through hole

[Duccout]

You are right, it is not easy. The car people seem to use yellow paste on their diffs, so let us know how you get on.


Cheers,

Colin

[Bevel bob]

I find that when using sealant its best to assemble the parts under gentle hand pressure on the fixings and then leave for an hour before tightening up. Then 24 hours to set.

[insanity]

A little bit interesting
if not flippin mind bogglin

https://www.youtube.com/watch?v=hG8J5wjQQRc

https://www.youtube.com/shorts/5cMDyHXMvf0?app=desktop

Have to pause to see the mesh contact pattern https://www.youtube.com/watch?v=xA0lWau1Gdc


the full monty https://www.belongear.com/production-videos/

[insanity]

Howdy,

Ebay post arrived, orange paste in tiny tub - but that is ok, can only get it by the litre locally.

The orange paste makes a difference, isopropyl alky washes it off, I think this is as close as I shall get.
Wotcher think ?

[Duccout]

That looks pretty good to me and I would be happy to achieve that meshing, but hopefully Nigel or Eldert will comment.


Cheers,

Colin

[LaceyDucati]

That looks good to me too, interesting paste.

[insanity]

Thanks Fellows,
Much appreciated,
72 year old eyes, I resorted to using phone to sharpen and magnify !
I took pretty much 6 hours of on and off, spin the back wheel. After even more time spent with blueing, just not enough contrast

Expensive but worthwhile

https://www.ebay.com.au/itm/32615364354 ... R_aAzfrJZA

Cheers

[insanity]

Hello all,

Found a seemingly a strange assembly on this bike.

The lower vertical cam drive shaft (which protrudes from the case) below the oldham coupler had some small dia shims sitting on top of the bearing,
but below the lower circlip.

BUT with that circlip it wont go together, it pushes the upper shaft upwards locking the gears at the camshaft.
So then, no circlip and the tube sits on the shims perhaps ? The Haynes manual does show a circlip P21 Item 13.
I really hope my custom bearing carrier isn't being a culprit.

As a note, the mesh of the bevel gears inside the case is nice and correct as there are grind marks on the pair, and they are flush, I tested with a needle showing they haven't been disturbed (the upper pair don't have grind marks, well, one does) .

Also the large dia spacer has shims but below the spacer, the manual says they go on top, do they ?


I appreciate your input.
Thanks

mr nutty

oh, photo of odd wear on the mating surface of the upper shaft.

[Duccout]

Hi,

The shims that are beneath the circlip are correct and are to remove play in the bearings. When the circlip is clicked into the groove it should butt up against the shims and there should be no side-to-side play in the gear if you wiggle it. The large shim goes on top of the spacer to prevent the lower bevel gear pushing up out of the housing.

Not sure what you mean when you say that the shaft won't go together with the circlip in place, the Oldham sleeve sits on top of that lower circlip. I am guessing that the two halves of the shaft are a little tight and are binding and are not slotting together fully. Try removing the upper shaft from the head and sliding it home in the Oldham coupling to see if it goes all the way down.


Colin

[insanity]

Hi Colin,
Thankyou,

I have disassembled and reassembled checking as I go to no avail.
Assembled as per the manual exploded view and the parts book as reference, and as I pulled it apart.

The gap between the lower circlip and the top of the bearing inner is such that the small dia shims have
room to float up and down, around a 3.5 mm gap, should there be 3.5mm of shims !.

In the images, the distance between the upper and lower circlips in situ (no head bolts) is about 32mm,
the length of the coupling tube is about 34mm just doesn't seem right, though the gap between the shafts isn't closed, if it were the gap between circlips would be less !

Perhaps that is why it failed to run and was stupidly hard to kick start and when it did run it smashed the
upper bearing and wore the hole in the head.