72 commando 750

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So I am going to use this as an all purpose kind of thing because I am in desperate need of information on this bike. I received the bike from my dad it is currently in pieces because I tore it apart to rebuild it proper and everything is going fine. Just have some questions and right now the big one is how do I change the fluid in the gearbox. I have the Bible for the bike and it never mentions once how to do this. I don't know what fluid it takes how much it takes and where it empties out and where it fills back up I would appreciate any of this info. And on a side note I see a diagram with an oil filter coming off the oil reservoir in the Bible but I do not have an oil filter or any contraption to put one in because it looks like it was an old paper filter inside a case similar to a fuel filter but attached to the hoses coming off the oil pan. Is this a part on the 750's or is this diagram inaccurate because this Bible I have also covers the 850's so not everything matches up. Thanks guys.
 
There are 2 bolts on the lower back of the gearbox; the lower one is the drain plug, the upper is a fill level plug. Fill the oil through the inspection cap until it reaches the bottom of the fill level plug. Oil is normally 85-90 wt gear oil.

Oil filters were offered after 1971 and are a standard automotive spin on filter. It would be mounted to a bracket on the engine/gearbox cradle on the right side behind the rear fender. If you don't have one it's not a '72.
 
See the Rider's manual for your year. The shop manual leaves out a lot of the day to day maintenance info that you will need as the new owner. They are available to download online. Good to see you continuing the family tradition. Good luck with it.
Russ
 
I have the Bible for the bike and it never mentions once how to do this.

I presume the "Bible" you are referring to is the factory workshop manual, please say if it isn't what you are using.

Changing the gearbox oil is covered in section K.
Fig K6 shows the location of the drain and level plugs etc.

And on a side note I see a diagram with an oil filter coming off the oil reservoir in the Bible but I do not have an oil filter or any contraption to put one in because it looks like it was an old paper filter inside a case similar to a fuel filter but attached to the hoses coming off the oil pan. Is this a part on the 750's or is this diagram inaccurate because this Bible I have also covers the 850's so not everything matches up.

The spin-on filter wasn't fitted until mid-'72 production (from eng. 208754) so if it's an early 200000 series (or '72 if you like?) 750 model then it would not have had the spin-on filter originally although the filter kit can be fitted to earlier models and is a worthwhile upgrade.

 
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So I am going to use this as an all purpose kind of thing because I am in desperate need of information on this bike. I received the bike from my dad it is currently in pieces because I tore it apart to rebuild it proper and everything is going fine. Just have some questions and right now the big one is how do I change the fluid in the gearbox. I have the Bible for the bike and it never mentions once how to do this. I don't know what fluid it takes how much it takes and where it empties out and where it fills back up I would appreciate any of this info. And on a side note I see a diagram with an oil filter coming off the oil reservoir in the Bible but I do not have an oil filter or any contraption to put one in because it looks like it was an old paper filter inside a case similar to a fuel filter but attached to the hoses coming off the oil pan. Is this a part on the 750's or is this diagram inaccurate because this Bible I have also covers the 850's so not everything matches up. Thanks guys.
Paul,
I am so glad that you are getting to work on your Dad's bike. As L.A.B. stated the Engine oil filter was introduced later in the production run and it is a very good idea to apply it to your new project while it is in pieces. Both my combats did not have oil filters installed @206900ish. If it is in pieces as you say there are dimensions for hole position to get one installed. The fluid in the gearbox is drained from the rear lowest plug on the rear of the gearbox shell. EP90 is the stuff but we will get into an oil battle if I carry on. Keep asking questions cause we are here to help.
cheers,
Tom
 
Just make sure the gear oil is GL-4.

GL-5 is suitable for hypoid gear service under severe service and shock loads and not for use in a gearbox.
 
So let me start by saying WOW great response guys lots of good info here I can't tell you how much I appreciate it. I'm going to try and answer all questions in this statement. I am sure it is a 72 because it was bought brand new. The Bible I have is most likely a workshop manual it is in a binder and printed on printer paper my dad claims that's what they gave him when he purchased the bike back in 73 and as far as not being sure about some aspects it is because I unfortunately did not tear the bike apart. My brother disassembled it and I was not there to help. I then received it literally in buckets and bags and of course the frame and engine were there but it is nearly as disassembled as possible so I have to sift through buckets to find parts and boy there are a ton of parts to this bike. He realized pretty quickly that he was a bit over his head and I fortunately have experience rebuilding cars and some work on bikes but for the most part and engine is an engine wether it's a Chevy 350 or a Kawasaki Vulcan 1500 so I know my way around these pretty well. I'm just struggling at this point because the "Bible" I have covers the 750-850 models and doesn't always discern what model the diagram is referring to and I am assuming it is because there are probably similarities to both models considering the engines are so close in size. But to end this extremely long post I cannot thank you guys enough for this info and now that I know about the gearbox oil I can drain and clean it and refill it seeing as how it seems to shift and move freely so I really don't want to tear it apart if it is unnecessary. So again thanks guys and I'll be back with more questions I'm sure and I'll have photos when this beautiful slice of history is back to it's former glory and tearing up the road again!
 
I presume the "Bible" you are referring to is the factory workshop manual, please say if it isn't what you are using.

Changing the gearbox oil is covered in section K.
Fig K6 shows the location of the drain and level plugs etc.



The spin-on filter wasn't fitted until mid-'72 production (from eng. 208754) so if it's an early 200000 series (or '72 if you like?) 750 model then it would not have had the spin-on filter originally although the filter kit can be fitted to earlier models and is a worthwhile upgrade.

Where can I find the production number? I do not see a plate on this bike with VIN or anything and like I stated before I didn't disassemble it so I have no way of knowing if there was a VIN originally and it got pried off when the frame was powder coated and tossed in a bucket somewhere. Is this perhaps on the engine block itself? Thanks in advance
 
The spin-on filter wasn't fitted until mid-'72 production (from eng. 208754) so if it's an early 200000 series (or '72 if you like?) 750 model then it would not have had the spin-on filter originally although the filter kit can be fitted to earlier models and is a worthwhile upgrade.

I have a template for drilling the cradle for the oil filter. It's MUCH easier than doing it by measuring. I made it from a cradle factory drilled for the oil filter. PM me and promise to send it back and I'll send it to you. I've used it to drill several cradles.
 
Where can I find the production number? I do not see a plate on this bike with VIN or anything and like I stated before I didn't disassemble it so I have no way of knowing if there was a VIN originally and it got pried off when the frame was powder coated and tossed in a bucket somewhere. Is this perhaps on the engine block itself? Thanks in advance
Left (drive) side of the engine case near the cylinders.
 
VIN=engine number is on the left side of the case, below the barrels. Same number should be on the gearbox. You can get a replacement VIN plate from Old Britts and stamp it.
 
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engine number is on the left side of the case, below the barrels. Same number should be on the gearbox. You can get a replacement VIN plate from Old Britts and stamp it.
You can get replacement VIN plate (actually called a Certification Label) from Andover Norton and you can specify how you want it stamped and they will stamp if for free. It normally will have the serial number (engine number) and the Month/Year of "manufacture". If you don't have the old one, you can order the factory record from them and make a best guess of what it should say for Month/Year or leave it blank. Learn more here: https://www.gregmarsh.com/MC/Norton/CommandoID.aspx
 
I'm surprised that AN would provide such a service. Selling the blank plate is one thing. Stamping the numbers with no "official" verification (original title/sales receipt, whatever) could involve them in any complaint re subsequent purchase/representation of the motorcycle. Since "matching numbers" can make a major difference in the the selling price of 'vintage' vehicle, if a question of fraud arose, wouldn't they automatically be a party to it if there was a complaint?
 
Paul,
get some pictures out of your Dad's bike for us to see and what's needed to be attended to. If I can't see anything weird, or someone else could pipe in, this will help.
At what stage are you ready to fire the old girl up at?
Keep on Keepin on..
cheers
Tom
 
One of the most useful publications is the parts manual.


Andover Nortons Part listings are also useful but assembly detail is often obscured by their part numbers.

Also, my vote for best Workshop Manual goes to Clymer. Get an original old one if you can, picture quality is better than the reprint. I got a tatty copy on eBay, that is even tattier now, but you will probably find it easier to get in the US.

Have fun. I wish I had your boxes of bits!
 
As mentioned, the parts diagrams are a great resource on seeing how things fit together. It's not perfect, but it helps a lot. Andover Norton supplies virtually all parts which is great for a 50 year old machine (wish some Japanese car companies did the same)


The Factory Service Manual is aonother great reference. You can get it online, but best to also have a hard copy which can be purchased for not a whole lot. Another good manual i found, as supplement to the FSM, was Clymer's (don't bother with Haynes). A good pictorial build thread is Chris Rooke's book (albeit an 850)


There's also a whole lot of good info on this site. I am about 3 months ahead of you and still learning a lot myself


Good luck
 
Mexico Mike very interesting point about stamping numbers I had a friend of mine do one for me but again, in case of a question arising who bears the responsibility?
 
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