Vernier Isolastic kit

Not with the long bonded isolastic rubber. The primary drive will have to come off, inner chain case off, gearbox out (cradle needs to be released from the back of the engine to unmask the slot in the RH cradle plate to allow the gearbox to be removed) Cradle and swinging arm can be removed together. About an hours work with the right kit

The method below is copied from the files section of the INOA List on Yahoo groups, posted there by Mike Taglieri.

I fitted my verniers using this method and it worked a treat.

Subject: Easier Way to Rebuild the Rear IsolasticThe standard workshop manuals for the Commando generally tell you that the rear Isolastic mount can be rebuilt only by removing the engine, or even the entire power train. Today, helping Chuck Contrino rebuild the rear Isolastic on his '72 Interstate. I was finally able to test a procedure I've been contemplating for a long time that lets you rebuild the rear Isolastic without significantly dismantling the rest of the bike. It worked very well, and this is how you do it:1. Remove the tank.2. Remove the primary (optional -- see below).3. Remove the horn (optional -- see below).4. Remove the air filter(s) and the exhaust pipes.5. Put the bike on the centerstand and fasten the centerstand with safety wire, electrical ties, bungee cords, etc., so it cannot possibly collapse. Do not fasten it to any part of the frame, but only to the engine plates or some other part of the bike that hangs on the Isolastic mounts.6. Slightly loosen the nuts on the large central bolt that runs through the rear Isolastic, and also loosen the nuts on the headsteady.7. Put a small hydraulic jack, etc., under the middle of the left frame tube (with padding to protect the frame) and slowly raise the side of the frame until the left foot of the centerstand just leaves the floor. At this point, the weight of the frame does not rest on the central bolt of the rear Isolastic, and you can remove it easily. Using a suitable drift (a 1/2" socket extension works well), tap the big bolt loose, catching the various metal parts of the Isolastic that fall free when it's out. (By the way, using a hydraulic jack this way is also useful for getting the bolt back IN when you're done, and you can look through the hole with a flashlight and move the frame until the parts are exactly aligned).8. Lower the hydraulic jack. Now the frame is hanging on the powertrain by the front and top Isolastics, and the top Isolastics show it by twisting slightly under the weight. Lift the rear wheel (with a 2x4", brick, etc.) until the top Isolastics are no longer twisted. Now, remove the side plates of the top Isolastics. (You do not have to remove the engine steady from the top of the engine).9. The powertrain is now resting on the floor, held up the centerstand, but it's attached to the rest of the bike only by the front Isolastic. Now, put more stuff under the rear wheel to raise the frame until the centerstand almost comes off the floor.10. At this point, the frame tubes are out of the way and the rear Isolastic is completely exposed on both sides for rebuilding.THE "OPTIONAL" STEPS: If you didn't remove the primary, the Isolastic is completely exposed only on the right side, and you will need some kind of hook to pull the rubber parts out. If you didn't remove the horn, the frame tubes will be partly out of the way but not entirely. I recommend taking off both of these items if you're removing the original Isolastic rubber parts, because if they're truly stuck in there, it's a %$#@ of a job to get them out. On the other hand, considering how awful a job it is to remove the horn, you may want to try this first with the horn in place and remove it only as a last resort. (By the way, if you pound on the central rubber with an ordinary drift to get it out, the rubber absorbs the shock of the hammer blows before they get transmitted to the edges. The best way is to pound on the edges of the rubber by using a very large socket on an extension as your drift).REMOVING THE HORN: As anyone knows who has tried it, this is one of the ultimate bastard jobs on the bike. You can do it with the rear wheel in place by unbolting just the front part of the rear fender (two bolts near the top, two nuts on studs near the bottom), and flexing the fender enough to "pop" it off the studs and move it down. These studs turn out to be the bolts that hold the horn mount, which you remove (teaching children in the area several new words in the process). Finally, you can squeeze the horn out of the space between the frame and the fender -- moving the rear axle as far back as you can will help.

I've just finishing off doing this job. On my 850 mk11a and fitted RGM iso

I removed the oil tank,air filter,carbs,horn and plate(only removed this to test the horn out)Front iso and top iso

Also the Z plates

. Worked from the right hand side and also used a scissor jack same as Iain did and on the side stand.

The rubber boots i inverted them and just rolled the boot over

Used red rubber grease to lube the tube from both sides this was a must do and excess can be cleaned off.

Can lift the engine to re-align,but need another pair of hands to put the bolt back in

Bit time consuming but i would do it again. Maybe best if the whole cradle is out

Good luck

There are 2 different widths of front cradle, pre MK3 is wider than the MK3. You can convert pre MK3 to MK3 by turning the longer side shorter to match the short side so they are equal in length, its 1/4" wider from memory. Have done it myself but then I have a lathe, you could post it to me if you are in UK.

This may help

http://www.basmotor.se/eng/teknik/norton/n_isolast.html

This was before vernier isos were made longer so suit pre MK3 cradles, so you could get a longer replacement.

Previously john_holmes wrote:

There are 2 different widths of front cradle, pre MK3 is wider than the MK3. You can convert pre MK3 to MK3 by turning the longer side shorter to match the short side so they are equal in length, its 1/4" wider from memory.

John, How did you hold the front mount in the lathe? Did you use a very wide centre and face plate at one end? I have a very similar (but completely unrelated) thing to work on.

Previously Jonathan Soons wrote:

Previously john_holmes wrote:

There are 2 different widths of front cradle, pre MK3 is wider than the MK3. You can convert pre MK3 to MK3 by turning the longer side shorter to match the short side so they are equal in length, its 1/4" wider from memory.

John, How did you hold the front mount in the lathe? Did you use a very wide centre and face plate at one end? I have a very similar (but completely unrelated) thing to work on.

I got the chuck to fit the ID of the main tube on the opposite end I wanted to do the cut eg the short end, then to make sure the cutting forces did not try to push the tube to one side instead of a cutoff cut I cut from the side on the full thickness of the tube and shortened the tube on the long end as the tool moved across. I have a 12" chuck which helps.

If I am using a weak holding method I always go for a cutting action that increases the holding force instead of pushing at 90, if I can't then I can go to a fine feed of 1.5 thou per rev and take a number of cuts with a very sharp tool. Saves on use of faceplates and 4 jaw chucks which weigh too much and too long to set up even though I have them.