I imagine you took it to the limit then used percussion?
Project Money Pit !
- Thread starter Stirlingmoz
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I took it to ‘my limit’ but it’s only a 2 leg puller so not the most stable.
I’ve discovered that Bayer make a bespoke removal tool
I’ve discovered that Bayer make a bespoke removal tool
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Motobins sell them.
Looking at your puller it should work,
Put as much load on it as you can.
Leave it outside tonight as it’s pretty cold.( I’m guessing the freezer is out of bounds as well.) more torque on the the puller in the morning
Blowlamp on the flange,and a good smack with a hammer on the top of the threaded screw..
Or buy the tool if you’ll use it again.
99415
£50.40.
Or about £200 cheaper than a new end cover
Looking at your puller it should work,
Put as much load on it as you can.
Leave it outside tonight as it’s pretty cold.( I’m guessing the freezer is out of bounds as well.) more torque on the the puller in the morning
Blowlamp on the flange,and a good smack with a hammer on the top of the threaded screw..
Or buy the tool if you’ll use it again.
99415
£50.40.
Or about £200 cheaper than a new end cover
Bit of progress today.
Managed to get the flange off which revealed the horrors beneath..
Then had another go at loosing the last cap head bolt retaining the gearbox rear cover.
Good old Torx bit and some heat did the job
Managed to get the flange off which revealed the horrors beneath..
Then had another go at loosing the last cap head bolt retaining the gearbox rear cover.
Good old Torx bit and some heat did the job
Now for some heat so we can finally see inside..
As you can see it’s a bit of a mess in there.
There is a mix of oily sludge, water and more of the polystyrene it came packed in.
Some serious cleaning required so we can see what we’re working with.
As you can see it’s a bit of a mess in there.
There is a mix of oily sludge, water and more of the polystyrene it came packed in.
Some serious cleaning required so we can see what we’re working with.
And I’ve found at least one smoking gun.
The reason I couldn’t get it to shift gear is a broken spring in the selector mechanism..
Since I took this image I’ve managed to remove the 2 selector forks and the shaft that they slide on,
There’s some wear on them - I think maybe too much - but I have a good spare set.
Just the output and intermediate shafts to remove now.
The reason I couldn’t get it to shift gear is a broken spring in the selector mechanism..
Since I took this image I’ve managed to remove the 2 selector forks and the shaft that they slide on,
There’s some wear on them - I think maybe too much - but I have a good spare set.
Just the output and intermediate shafts to remove now.
Great job you are doing there, and to be honest those gearbox internals look way better in the pictures than I was expecting (though I would say that being a Marine Engineer and used to finding horror stories).
I managed to remove the output and intermediate shafts today and given the gearbox case a good clean.
Not finished - but certainly an improvement
Not finished - but certainly an improvement
And then it all went a bit sideways.
Another smoking gun.
Having cleaned the gearbox case, I could actually read the code number stamped on the side.
This indicates it’s an 85 box.
A quick look at the output shaft and - no circlip ! Not only that, but the helical gear is slightly wobbly on the shaft. Further inspection and the the outer race of bearing itself is cracked
Classic symptoms of the ‘no circlip’ scenario on this era of gearbox.
Does this also explain the wear on the side faces of the shifter forks ?
Anyone got a spare output shaft they’re willing to sell ?
Not much point rebuilding it with a worn output shaft
Another smoking gun.
Having cleaned the gearbox case, I could actually read the code number stamped on the side.
This indicates it’s an 85 box.
A quick look at the output shaft and - no circlip ! Not only that, but the helical gear is slightly wobbly on the shaft. Further inspection and the the outer race of bearing itself is cracked
Classic symptoms of the ‘no circlip’ scenario on this era of gearbox.
Does this also explain the wear on the side faces of the shifter forks ?
Anyone got a spare output shaft they’re willing to sell ?
Not much point rebuilding it with a worn output shaft
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I’ll have a look on Tuesday
That would be awesome - thank you
Excuse my ignorance, I know very little about airheads. Is it possible to machine a circlip retaining groove into the shaft to solve your problem? Does the helical gear run on needle rollers ??
I assume you would be replacing all bearings and seals as a matter of course ?
I assume you would be replacing all bearings and seals as a matter of course ?
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I always machine a groove and fit a Circlip if the shaft hasn’t got one fitted.
If the bearing pushes off the shaft slightly the 5 th gear will have excess end float,
Is it just this you are seeing or is the shaft actually worn?
I haven’t pulled the bearing off the shaft - yet - looking at various bearing puller kits on eBay.
I noticed as soon as I pulled the shaft out of the case, there was no circlip on the hidden end and my heart sank a little.
The helical gear has a v small amount of lateral movement along the shaft and some discernible radial movement - it is rocking on the shaft itself.
The shift forks are very polished and look like they have been rubbing.
I have a nice set of shift forks in my spares stash so that’s not a problem.
I now know it’s good practice to change all the gears at the same time and they are available as a complete set. False economy not to do this, particularly on this gearbox which has had water ingress.
I noticed as soon as I pulled the shaft out of the case, there was no circlip on the hidden end and my heart sank a little.
The helical gear has a v small amount of lateral movement along the shaft and some discernible radial movement - it is rocking on the shaft itself.
The shift forks are very polished and look like they have been rubbing.
I have a nice set of shift forks in my spares stash so that’s not a problem.
I now know it’s good practice to change all the gears at the same time and they are available as a complete set. False economy not to do this, particularly on this gearbox which has had water ingress.
£££££££££ !
You’re not wrong but a good airhead gearbox is now an expensive thing and I’m trying to teach myself a new skill and string swear words together in whole new order.
(I cheated on my previous gearbox refurb and got Mikey to build it for me
)
It only owes me £100 and a few hours work at the moment so I’ve got some headroom.
However, a worn output shaft is likely a deal breaker. If I can’t source one I’ll cut my losses and try and sell it for parts.
(I cheated on my previous gearbox refurb and got Mikey to build it for me
)It only owes me £100 and a few hours work at the moment so I’ve got some headroom.
However, a worn output shaft is likely a deal breaker. If I can’t source one I’ll cut my losses and try and sell it for parts.
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The thing with anything mechanical,is you need to understand in the first instance,what you are looking at.
Then,what is repairable,serviceable or scrap.
On a second look,is what the primary use will be.
If a gearbox is going to be raced or taken to Mongolia,it needs to be tip top.
However,it said gearbox is only going to be used locally for bike nights it may not need the same amount of expensive parts.
Then,what is repairable,serviceable or scrap.
On a second look,is what the primary use will be.
If a gearbox is going to be raced or taken to Mongolia,it needs to be tip top.
However,it said gearbox is only going to be used locally for bike nights it may not need the same amount of expensive parts.
Chances are, a good cleanup along with fresh seals and bearings where needed and a few new parts and it will be a good useable gearbox.
My cheapo second hand Chinese bearing puller was on my doorstep when I got home today.
Had a quick go, just to see what it will do..
Pretty chuffed that it worked quite so easilly. That bearing is absolutely cream crackered. So much play, I’m surprised it’s still in one piece.
Had a quick go, just to see what it will do..
Pretty chuffed that it worked quite so easilly. That bearing is absolutely cream crackered. So much play, I’m surprised it’s still in one piece.
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You’ve not achieved or learned anything though.
What is the 5th gear fit like with the bearing pressed properly down.?
I’ve got a good output shaft ,but you don’t know if the issue you have is the shaft or just the gear?
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