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TBW

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Nov 3, 2011
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Hi all. I have what I believe is an Atlas or Dommie gearbox , serial number N 17484 , that I’m looking to use in my ‘72 Combat whilst I overhaul the original. It appears to have been overhauled - assumption based on obvious new gaskets , new kickstart splines etc. However I’ll open it for assessment ;

Questions for the learned community i.e, everyone aside from me: apart from checking mounting lug measurements, installing longer lay shaft ( which I have) and -possibly - new bearing…will it fit ? ; is it suitable?

Many thanks.
 
As far as I know yes it'll be fine
I think you can also use a stepped clutch centre from RGMs to allow you to use the original short main shaft instead of changing to the longer commando type?
Hopefully someone will correct me if I'm wrong
 
AFAIK the gearbox shells are not identical. If you have an AMC-M type of shell, location of lugs won't suit the Commando. If you have the AMC-N type of shell, I believe the top lug needs machining to make it suitable for the Commando cradle. Not sure of the bottom lug.
Otherwise, the shells should be nearly identical. The 1962 onwards shell (AMC-NA) may be a tad stronger than the 50's shell which you have.

- Knut
 
The kick start spring and its location , tho working is not the same , you may /will find that it is more lazy to come back !
 
The kick start spring and its location , tho working is not the same , you may /will find that it is more lazy to come back !
Also the outer gearbox cover has the clutch cable entry point further back on a pre commando gearbox and won't work with the commando setup
 
As far as I know yes it'll be fine
I think you can also use a stepped clutch centre from RGMs to allow you to use the original short main shaft instead of changing to the longer commando type?
Hopefully someone will correct me if I'm wrong
Baz, thank you. As per your later reply I did mean Main shaft 👍. I’ll open it up for inspection etc.
 
AFAIK the gearbox shells are not identical. If you have an AMC-M type of shell, location of lugs won't suit the Commando. If you have the AMC-N type of shell, I believe the top lug needs machining to make it suitable for the Commando cradle. Not sure of the bottom lug.
Otherwise, the shells should be nearly identical. The 1962 onwards shell (AMC-NA) may be a tad stronger than the 50's shell which you have.

- Knut
Thanks Knut. I was kinda aware of some machining requirements having researched here and NOC site. 🙏
 
Marin, thanks . I wonder if I can use my outer case to solve this whilst I overhaul my original 🤔
The kickstart return spring is retained by the inner gearbox cover
And as stated earlier the outer cover cable entry point is not compatible with a commando
 
Hi Baz , understood. So do you know if outer covers are interchangeable?
Hi TBW
I have just done the same thing and built an earlier race GB back to road use for my '68 commando while I rebuild the original and the covers will fit but if you use the cdo KS shaft and spring you will need a commando cover ,the bigger spring fouls on the outer cover .Not sure about the inner as mine had the modified inner cover so was replaced also lay shaft shortened and no KS shaft . Cable inlet angle was also a consideration with the early oil tank and battery carrier.
 
Thanks AJS. I’m considering using the outer cover with re-routed/ modified clutch cable for the relatively short time - permanent optimist- for the original g/b overhaul…so happy to cope with kick start etc.
Appreciate sharing your experience 🙏
 


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