removing rear isolastic and swingarm

fendermanz

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Nov 13, 2023
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71 commando 750 isosHi been trying to read the posts but most I look at seems to look different from what I have. I don't see the nuts on this one. I also do have a factory manual. Just want to know how do I remove the rearisolastic snd swingarm on this bike. Too much grease inside to see what's in there lol. Thanks in advance
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New item by Garrett R

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Start with the isolastic. It is held in with a single length stud (#46 see here) from one side to the other that is held in place with nuts at each end - I do not see that you have the nuts but you do seem to have something there? Sharp blows with a hammer and punch to start and as you get it moved in use Liquid Wrench to free it up and further it along. The swing arm similarly has a pin through it (#21 see here) though much larger - clean everything up first so there is no particulate and again you are hitting it with a hammer and something like a punch tool, or thread a bolt into the female end of the pin and attempt to draw it out - your call as your tool set permits.

removing rear isolastic and swingarm
 
fendermanz said:
71 commando 750 isosHi been trying to read the posts but most I look at seems to look different from what I have. I don't see the nuts on this one. I also do have a factory manual. Just want to know how do I remove the rearisolastic snd swingarm on this bike. Too much grease inside to see what's in there lol. Thanks in advance
photos.app.goo.gl

New item by Garrett R

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Too much grease inside the manual? The factory shop manual is excellent : both procedures and drawings. They should be kept grease and oil free. A Commando Parts Catalogue to supplement the resources is useful
 
It is probably someone's idea to save weight by tapping threads inside the ISo tube and saving the weight of the thru bolt. Remove socket head cap screws and tap cradle forward Don't know what your plans are for this frame, but I would be concerned with the thru hole. The rear hole is in a high stress area.
 
That looks like the spacer, that belongs there, just rusted in place.
Knock it off.
Swingarm removes per the manual.
Cradle will slide out from between the frame. May be rusted, from the looks of the rest of it.
 
Clean the grease off and start with the swing arm spindle, easier to deal with, with it still held in the frame. Use a length of 1/2 UNF stud bar, nuts, washers and suitable spacers to pull the spindle out of the arm/cradle. You may have to use a 1/2 UNF tap to clean the thread in the spindle to allow the stud bar to screw in.
Now to the iso stud, is the long iso stud removed? The photo just shows a tube? I would cut the rubber gaiters off and saw through the iso end caps, easiest done with a thin cut off wheel in a angle grinder. That gets the cradle out the frame without damaging them. The cost of replacing the iso rubber, end caps and spindle is nothing compared to repairing bent frame plates etc that can happen when hammering seized/rusted things trying to get them out. One thing that experience gives you is knowing when to sacrifice some bits to save other stuff.
You are going to have to get busy with a welder, looking at the photo again there are holes in the frame tubes putting a question mark over the frames integrity
 
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dobba99 said:
Clean the grease off and start with the swing arm spindle, easier to deal with, with it still held in the frame. Use a length of 1/2 UNF stud bar, nuts, washers and suitable spacers to pull the spindle out of the arm/cradle. You may have to use a 1/2 UNF tap to clean the thread in the spindle to allow the stud bar to screw in.
Now to the iso stud, is the long iso stud removed? The photo just shows a tube? I would cut the rubber gaiters off and saw through the iso end caps, easiest done with a thin cut off wheel in a angle grinder. That gets the cradle out the frame without damaging them. The cost of replacing the iso rubber, end caps and spindle is nothing compared to repairing bent frame plates etc that can happen when hammering seized/rusted things trying to get them out. One thing that experience gives you is knowing when to sacrifice some bits to save other stuff.
You are going to have to get busy with a welder, looking at the photo again there are holes in the frame tubes putting a question mark over the frames integrity
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Not just the frame tubes - looks like someone went crazy with a drill on the cradle
 
baz said:
I'd assume they are go faster holes
Can't explain the one through the frame though !!!!
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All those drill holes have NO rust on the bare steel. Fresh abuse wounds????
Not deburred, standing razor blades on the perimeter.

O.P., what can you tell us about the cheese holing?
 
OUCH!

The frame holes need to be brazed up, and the transmission cradle needs to be replaced.

I have a spare cradle on hand.
 
YING said:
Rob,

I couldn’t figure out what all those holes are for and why!Scary
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I wish I knew, Whoever owned this bike previously should never work on a bike ever. I just got this bike and am tearing it down . I figured u guys would see the cheese grater uggh. This guy was using crafty pipe cleaner to hold wires. mixture of bolt sizes on the head. Pistons looked good, turns over fine. I'm used to old harlies and jap bikes, this is my first teardown of a brit bike.
 
fendermanz said:
I wish I knew, Whoever owned this bike previously should never work on a bike ever. I just got this bike and am tearing it down . I figured u guys would see the cheese grater uggh. This guy was using crafty pipe cleaner to hold wires. mixture of bolt sizes on the head. Pistons looked good, turns over fine. I'm used to old harlies and jap bikes, this is my first teardown of a brit bike.
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Maybe find another frame & cradle to use.
 
That cradle could be replaced with an alloy one with no loss of strength/stiffness :rolleyes:
 
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