Overdrive gearbox

Paul Goldsmith

Paul Goldsmith

0
I've discovered a Humber Sceptre o/d gearbox but it's for the older (ie. not Hunter based) Sceptre but still 1725 engine.

I'm guessing to fit the Commer I'll need to swap over the Commer bell-housing and gear selector mechanism so that existing linkages etc can be used plus shorten the propshaft and fabricate a new gearbox crossmember support.

I've got a Sunbeam Rapier 1725 alloy engine already but don't have any idea whether this older gearbox would be compatible still, so any suggestions welcome

Thanks



th_Commer_carpark.jpg

Commer 'Hi Tor' by TorCars
 
Hi Paul - you maybe lucky and find that the bellhousing is the same as the Commer either way it will fit onto the engine. If you can find a Rapier prop, or any other OD boxed car, from the 'Hunter' range then it will fit without modification as long as you use the Commer bell housing.

Harvey the RV
 
Thanks Panky, quite exciting ! With your o/d setup have you replaced the top gear selector unit with the Commer one though and was it a big job ?

Being the older gearbox am I correct is assuming it's likely to be D-type overdrive rather than the later J-type. What are the pros/cons of each ?

Cheers


th_Commer_carpark.jpg

Commer 'Hi Tor' by TorCars
 
The selector forks stay in place as they are the same - the top housing for the linkage just bolts straight on. You will need to make sure the inhibitor switch is screwed into position on the righthand side of the box - it only just clears the cotter pin on the linkage - there is usually just a plug in place on the Commer box where the switch screws in.

Don't know the pros and cons of the different types - bothe seem to work as well as each other in the conversiona I'v seen and heard about. I think there was another type as we - the 'O' type but I think this was quite rare.

Harvey the RV
 
dont forget to check the splines are the correct type.the earlier od boxes as fitted to the early vogue/superminx/sceptre had a fatter spline and arent compatable with the hunter/rapier props,all you have to do is take the spline off the later prop and swop it with the correct one off an earlier car
 
Also at the other end of the box the number of splines on the input shaft can differ.

Harvey the RV
 
swapping the bellhousing may (or may not) be a pain. The input shaft needs to go with it, and to swap that you need to take some er... bits out of the box - pretty straightforward but you just need to take your time.

mmm overdrive ...

I now get annoyed when I'm driving my Skoda as I can't flick the overdrive on when I'm in 3rd. I'm also trying to work out how to fit one to my minor!

Rupert



"With great cars comes great responsibility"

www.littleyellowcar.co.uk
 
quote:
Originally posted by BigMonkeyMan
[ I'm also trying to work out how to fit one to my minor!

Rupert



With great cars comes great responsibility

www.littleyellowcar.co.uk


easiest solution to that Rupert is fit a Riley 1.5 diff, 3.7 and straight in, i just happen to know where there is one going spare soon ;)





"you were only supposed to blow the bloody SLIDING doors off"
 
quote:

easiest solution to that Rupert is fit a Riley 1.5 diff, 3.7 and straight in, i just happen to know where there is one going spare soon ;)




I have a 3.9 diff in the garage that I got years ago - probably lots better than the 4.2 I have not and loads better than the 4.5 it used to have. Saying that I'm worried I'll loose the low down nippyness. Might as well suck it and see I suppose.

Would the riley 1.5 diff fit into the minor housing?

Rupert


"With great cars comes great responsibility"

www.littleyellowcar.co.uk
 
BMM, why don't you go the whole hog and fit a Rover V8? A work pal of mine had one in a Moggy pick up, he reckoned it was dead easy!

Not that I know bugger all, just what he said lol

'A brave man when Cazz is asleep'
 
quote:
Originally posted by Enigma

BMM, why don't you go the whole hog and fit a Rover V8? A work pal of mine had one in a Moggy pick up, he reckoned it was dead easy!

Not that I know bugger all, just what he said lol

'A brave man when Cazz is asleep'



thread hijack...

I like my mods in keeping with the original... So I've gone for similar A series mods and general BMC stuff.. I'd like a V8 minor (or just a Fiat twink) but not in Molly. She's one of the family and anything too severe would be too much of a shock!

Rupert

"With great cars comes great responsibility"

www.littleyellowcar.co.uk
 
I know what you mean - the custom jobs are great (and one day I will have one) but to carry out radical surgery on something that has been a part of you for so long - just seems wrong. I like the idea of evolution - producing something the manufacturers should have done [^]

Harvey the RV
 
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