How to Remove Engine from Frame

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thunderbolt

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I have pretty much stripped everything off the frame apart from the engine, gearbox and swing arm. Pictures below to show current situation. Pictures show bike loaded to go off to a guy that does frame and fork straightening to check frame and forks for straightness.

What is the best procedure for removing the remaining parts?

Do I need to remove cylinder head and barrels before lifting the engine out?

Can I remove the gearbox from the engine plates without removing outer and inner covers first?

How is it best to remove the swing arm and engine cradle? How to support frame while these bits are removed?

Are there any parts that are going to be hard to remove? e.g. swing arm spindle, etc.

Do I suspend frame from roof rafters to remove swing arm (I guess it comes off last)? Or just lay the frame on the grass and pull it out that way? Or does the swing arm come off first?

Please help with your great suggestions.

How to Remove Engine from Frame


How to Remove Engine from Frame


Cheers
Don
 
Don,
You should be able to remove the engine as a unit. Take the top iso off from the head and the frame completely. Take the front Iso off the engine and the frame completely.
Undo the three bolts from the engine/gearbox cradle. If you have a good back you can pull it out from the timing side without any issues. Remember the gearbox goes back in first before you button up the engine in the reverse order (on some models) as you put the bike back together. The Gearbox should come out next after the engine is out. Two fasteners at top and bottom. Pay attention to the 1/8" spacer on the drive side of the upper bolt hole. It needs to go back to this spot. I have seen too many Norton Commandos with this spacer in the wrong location. Everything else should be straight forward. There is a bolt that holds the swing arm shaft that you must remove first. If the shaft is tight you can thread the rear Iso shaft into the swing arm shaft and use it as a slide hammer with some ingenuity. Its all in the Norton Commando manual.
Cheers,
Thomas
CNN
 
CanukNortonNut said:
Don,
You should be able to remove the engine as a unit. Take the top iso off from the head and the frame completely. Take the front Iso off the engine and the frame completely.
Undo the three bolts from the engine/gearbox cradle. If you have a good back you can pull it out from the timing side without any issues. Remember the gearbox goes back in first before you button up the engine in the reverse order (on some models) as you put the bike back together. The Gearbox should come out next after the engine is out. Two fasteners at top and bottom. Pay attention to the 1/8" spacer on the drive side of the upper bolt hole. It needs to go back to this spot. I have seen too many Norton Commandos with this spacer in the wrong location. Everything else should be straight forward. There is a bolt that holds the swing arm shaft that you must remove first. If the shaft is tight you can thread the rear Iso shaft into the swing arm shaft and use it as a slide hammer with some ingenuity. Its all in the Norton Commando manual.
Cheers,
Thomas
CNN
Click to expand...

Thanks Thomas, comments appreciated,

Back is not that good, but ok for 68yo. Might need some help with it though.

Cheers
Don
 
thunderbolt said:
CanukNortonNut said:
Don,
You should be able to remove the engine as a unit. Take the top iso off from the head and the frame completely. Take the front Iso off the engine and the frame completely.
Undo the three bolts from the engine/gearbox cradle. If you have a good back you can pull it out from the timing side without any issues. Remember the gearbox goes back in first before you button up the engine in the reverse order (on some models) as you put the bike back together. The Gearbox should come out next after the engine is out. Two fasteners at top and bottom. Pay attention to the 1/8" spacer on the drive side of the upper bolt hole. It needs to go back to this spot. I have seen too many Norton Commandos with this spacer in the wrong location. Everything else should be straight forward. There is a bolt that holds the swing arm shaft that you must remove first. If the shaft is tight you can thread the rear Iso shaft into the swing arm shaft and use it as a slide hammer with some ingenuity. Its all in the Norton Commando manual.
Cheers,
Thomas
CNN
Click to expand...

Thanks Thomas, comments appreciated,

Back is not that good, but ok for 68yo. Might need some help with it though.

Cheers
Don
Click to expand...
Invite your mates over for a beer! :D
Cheers,
Thomas
CNN
 
Since you are that far down, are you planning on painting the frame, cradle, etc.? If so I would pull the rear wheel, swingarm, centerstand, and Z-plates. Put a large piece of carpet or blankets down on the floor and lay the frame/engine assemble on its side. Pull the isolastic studs and headsteady and front motor mount and remove the frame from the engine. Much lighter! (26 lbs.) You can then unbolt the cradle and gearbox from the engine.

When you put the engine back into a newly painted frame, reverse the procedure and you will reduce the risk of dinging that new paint.
 
Ron L said:
Since you are that far down, are you planning on painting the frame, cradle, etc.? If so I would pull the rear wheel, swingarm, centerstand, and Z-plates. Put a large piece of carpet or blankets down on the floor and lay the frame/engine assemble on its side. Pull the isolastic studs and headsteady and front motor mount and remove the frame from the engine. Much lighter! (26 lbs.) You can then unbolt the cradle and gearbox from the engine.

When you put the engine back into a newly painted frame, reverse the procedure and you will reduce the risk of dinging that new paint.
Click to expand...

Thanks Ron,

It all sounds like common sense to someone like me that has NO Commando experience. Yes the plan is to remove the engine, gearbox, cradle, swing arm, etc. Send the frame and other bits off to be sandblasted after they come back from the frame guy and then sent off to the painter for a lovely gloss black finish.

On reading the manual it talks about removing a nut and washer and withdrawing a long thin bolt/stud which holds the two end plates of the swing arm pivot in place and stops the oil coming out. If you look at the pictures I posted on my bike these are plain plates. There is no nut, washer, long thin bolt passing through the swing arm pivot. Or am I missing something here.

Thanks
Don
 
Don,
Looking closer at your frame it looks like a 72 or earlier. Not too sure. These would have a swing arm like this. http://www.oldbritts.com/1972_g11.html
if your bike is a 73/74 then this is how it should be: http://www.oldbritts.com/1973_g14.html
some one might have put in some non standard blanking plugs.
look at the swing arm and tell us what type of support you have across the tubes. If its got triangular gussets that would be for a 73/74 bike. if you don't have any gussets and just a tube across then its 72 or earlier.
What is the serial number range for the bike? e.g. 2068XX would help.
Cheers,
Thomas
CNN
 
CanukNortonNut said:
Don,
Looking closer at your frame it looks like a 72 or earlier. Not too sure. These would have a swing arm like this. http://www.oldbritts.com/1972_g11.html
if your bike is a 73/74 then this is how it should be: http://www.oldbritts.com/1973_g14.html
some one might have put in some non standard blanking plugs.
look at the swing arm and tell us what type of support you have across the tubes. If its got triangular gussets that would be for a 73/74 bike. if you don't have any gussets and just a tube across then its 72 or earlier.
What is the serial number range for the bike? e.g. 2068XX would help.
Cheers,
Thomas
CNN
Click to expand...

The engine, gearbox and VIN (on headstock) are all 315001. Date on VIN plate is 5 - 74. Frame No. is 850 - F109919.
 
Ok It looks like the 73/74 swing arm is in place.
Don, you see the bolt at the 12 o'clock on the engine cradle swing arm tube covered in grime at the center and left of the oil pipe. that needs to come out to remove the swing arm spindle. It looks like the plugs are from a 75 M3....maybe... he says (I). but because I don't know squat about Mk3's, then L.A.B. or others with 75's will need to clarify. Why you have this type plug in there is a mystery to me.
Slowly we are getting there.
Cheers,
Thomas
CNN
 
thunderbolt said:
On reading the manual it talks about removing a nut and washer and withdrawing a long thin bolt/stud which holds the two end plates of the swing arm pivot in place and stops the oil coming out. If you look at the pictures I posted on my bike these are plain plates. There is no nut, washer, long thin bolt passing through the swing arm pivot. Or am I missing something here.
Click to expand...

The late Mk2/2A models such as yours had the 'Mk3' 'sealed for life' swinging arm pivot assembly which requires the removal of the welch (not Welsh) plug or plugs in order to extract the spindle.

Removal of the plug often involves drilling a hole, inserting a reasonably substantial self-tapping screw and then pulling/levering on the head of the screw to deform the plug sufficiently to release it.

https://andover-norton.co.uk/en/shop-dr ... chainguard
 
It seems it was a good idea to use the Mk3 welch plugs, so why didn't they use the two bolts to hold the spindle in place instead of the one bolt on earlier models.

Cheers
Don
 
thunderbolt said:
so why didn't they use the two bolts to hold the spindle in place instead of the one bolt on earlier models.
Click to expand...



I have no idea.
Perhaps they hadn't thought of it at that time, or maybe it was considered too drastic a change to introduce in the middle of the production 'year' as it would have meant fitting a new type of cradle?

Or perhaps they were just saving the best things 'til last (Mk3)? :wink: :lol:

(The Mk3 "bolts" are cotter pins) https://andover-norton.co.uk/en/shop-de ... cotter-pin
 
Lay the bike down with a stack of semi-flattened cardboard boxes under the engine.

Un-bolt the power unit and flop it out onto the cardboard.

Hard part is done.
 
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