Mashed Gearbox

[metalguru]

Well it had to happen sooner or later, just coming home from work on my favourite bit of roadporn and chasing a Ducati, went to hook it up into 4th and CLANG....no drive, then heard all the familiar noises of things breaking. Found third gear and got it home with lots of grating and grinding, luckily only about a mile from home.
Pulled the engine out, removed sump and found 4th gear devoid of teeth.
well at least half the width. With much searching found the Daytona gearbox uses the same components as the Tigger, £45 later and have an 04 4k miles box heading my way complete.....Bargain. Not so much of a bargain were the gaskets and seals at £95....ouch.
All I've got to do now is strip it and clean out the mess and rebuild it. Will post some pics later.

[BigDan]

Oooh eck! At least you have the know how to sort this yourself.

[Bixxer Bob]

Oooh eck!

Master of the effin' understatement....... :lol:

[Timbox2]

Bad luck mate how many miles were on the box?

[metalguru]

This was about the right mileage these break if the gears are faulty at 30K. Mine has now done 29K!!! The selector barrel pins are showing signs of wear too.

Here is the damage to the gears after stripping out today, left out the boring bit of getting to them as the manual shows that.





And some of the larger shards in the sump.




Parts all ordered now and just have to wait for delivery, hoping to get it back together over the weekend, trouble is work gets in the way during the day DOH.

[Bixxer Bob]

Looks like it wasn't engaging fully.  Any evidence as to why?

[metalguru]

When the parts arrive I can compare and see the wear.
It has occasionally given a duff shift which will give rise to wear on the dogs etc as you rightly say. I cleaned up the lower case that still has the shift assembly installed and worked the gear selecor barrel a few times, it isn't as nice as I would like, so could be a culmination of all components

[iansoady]

Looks like it wasn't engaging fully.  Any evidence as to why?

That's what I would have said although to cause damage like that there must be a fault in the material / heat treatment etc.

[Chris Canning]

It ain't one of the great gearboxs in the first place,I've found  you can do lots with a Tiger,but rush the gearbox isn't one of e'm.

29000 blimey thats bad karma  :(

I'm not making any suggestions,but out of interest how often do you or anyone else change the oil.

[metalguru]

Not wishing to start yet another oil thread but changed the oil 4000 miles
ago and using fully synthetic. I am very keen on oil changes and it never
reaches the change limits on time or miles.
The end result is definately a mis-shift but it has been doing this since I
bought it about 18 months ago, occasionally giving a mis-shift more when the gearbox was not up to temp. 2nd to 3rd and 3rd to 4th which is consistant with the damage.
Thinking back my 855i was similar but not as bad but my steamer was great, never missed a shift and better shift.
This makes me think that it is initially a wear problem but will be able to compare the replacement and form an opinion.
The shifter drum is also under suspicion and again will compare.
Just waiting for the parts to get here now as all showing as despatched.

[Sin_Tiger]

I'd go with the shifter drum being the culprit too.

[Bixxer Bob]

Me too. If it's not been fully engaging for a long time the teeth stripping is not a great surprise. :?

[metalguru]

Just an update on events,
Managed to get the engine back together today and ready to go back in, just waiting on an inlet manifold gasket.
The interesting thing is, the selector barrel is totally different along with the selector forks having different casting numbers.
The gears are a different colour black to the ones I took out.
My deduction from this is although the same part numbers, the parts are different and possibly improved or modified. The shift as it is now feels different and more positive.
The different colour of the gears shows a different temp for heat treatment. Although the Daytona the g/box came from is the same year as my Tigger and the part numbers are identical there were obvious changes made.
Just to show the difference in the selector barrel here is a picture to compare.

[metalguru]

Next Update.

I have now found the reason the selector barrel is different.

When I put the engine in the frame today and connected everything up I thought the gear change had stuck!!! Was ok I thought as tested ok.
Now call me stupid/daft/inept/didn't check before buying/etc, the Daytona has a gear linkage, the Tigger doesn't, what this means is I now have a race bike shift.
Now it is 1up and 5down........wait for the comments!!!
I do prefer this pattern (luckily) as it is easier to change up the box, just lay your foot on the lever and pull the clutch. It was the same on my old Steamer as that had a non Tigger engine fitted.

As a precaution the gear lever rubber has been replaced as worn, also a contributor to mis-shifts.
The 3rd to 4th and 2nd to 3rd shifts produce several movements in the box compared to other shifts, another contributor for mis-shifts.
Would have had it running today but the inlet gasket didn't show, so looking at lift off next week fingers crossed it will be OK.
BTW the gear shift feels substantially better in all aspects.

Time for a beer or five............. :D  :D  :D

[metalguru]

Last update,

Set the bike up today as changed the TPS and balanced the throttle bodies, rather suprising they were out, they were only set about 4k ago.
Got a few issues with the mapping to sort but nothing bad.

As for the gearshift, it is better by a long way, going up and down the box very easily and quicker than it did before with a more positive feel to the shift.
I have always prefered the down for up GP pattern shift as it seemed logical perhaps why race bikes use it and old Brit iron.
I think it was a culmination of several components in the box that caused the failure.
The hardening, or lack of it, on the gears, the wear in the selector barrel and mechanism, the gear change lever rubber and of course me.

Back on the road in a week, interupted by work and good service to Lings for supplying gaskets and stuff

Now lets see if I can find a Ducati to play with.......if it ever stops raining.