Retrofit overdrive cost availability?

[tonydgray]

Hi all

Has anyone got any thoughts regarding fitting an overdrive to an existing 4 speed manual(1973 145) regarding the cost/availability/parts required etc. I'm just wondering if it would be a viable option or not.

Thanks

Tony

[classicswede]

You will need,

OD Box
OD prop or shorten your existing one.
OD switch

[Dylan144GT]

Hi tonydgray

If you find an M41 (M40 + overdrive as complete unit) all you need it the shortened prop, od cross member and switch as mentioned by classicswede. I'd say this is the easiest route. If you want to convert a M40 (Std 4 speed gearbox) you'll need the conversion kit that consisted of the elongated output shaft, the actual overdrive (Triumph owners had the same one), the shortened prop, od cross member and switch. I've seen the conversion kit elongated shaft on ebay once. Maybe someone has a part number for you.

Dylan

[laptoprob]

Originally Posted by Dylan144GT

Hi tonydgray

If you find an M41 (M40 + overdrive as complete unit) all you need it the shortened prop, od cross member and switch as mentioned by classicswede. I'd say this is the easiest route. If you want to convert a M40 (Std 4 speed gearbox) you'll need the conversion kit that consisted of the elongated output shaft, the actual overdrive (Triumph owners had the same one), the shortened prop, od cross member and switch. I've seen the conversion kit elongated shaft on ebay once. Maybe someone has a part number for you.

Dylan

True. I sold my M41 unit, but still have the shortened shaft and the original crossmember. But shipping from Holland may be heavy/pricey.

[john h]

If you can weld, the gearbox crossmember can be cut and modified to fit.

It's well worth the effort of fitting OD. Makes a massive improvement to cruising ability.

John

[tonydgray]

Thank guys, does anyone have any thoughts on where the best place to source bits for the conversion whether it be an M41 box or converting the M40 box with a kit? Nothing on ebay at the moment, I suppose I need to put a wanted advert somewhere and see what happens?

Cheers

Tony

[marcmarel]

No such thing as an M40-M41 conversion kit. A man in Holland makes his own output shafts and can bolt on a J type. Price is not bad either, 575 euro.
It's all in Dutch: http://www.frankefort.nl/overdrive/index.html

It is worth looking at wreckers and cars sold for parts etc, I once found a working M41 under a 145 donor that I got for 200 euro. Lots of folks don't know what an OD looks like or what it's worth.

[tonydgray]

Hi guys

I posted before asking about what was required to fit an overdrive unit to my 145(1973). Thank you all that replied and the general consensus seemed to be that I needed the overdrive box, prop and switch.

I have now sourced a Volvo "M410 gearbox with J type overdrive as fitted to late Volvo P1800E ES and 164" and I hope this is not going to be to difficult coupling it up to my B20. I assume that if I had sourced an M41 as apposed to an M410 then it might have gone together a little easier. Can anyone give any direction as to whats bits I need now that I have the M410?

Many thanks

Tony

[laptoprob]

Wow Tony!
That's the strongest one around. You will need the crossmember and a shortened prop. Any switch can do.

good luck!

Rob.

[940_Turbo]

Originally Posted by tonydgray

Hi guys

I posted before asking about what was required to fit an overdrive unit to my 145(1973). Thank you all that replied and the general consensus seemed to be that I needed the overdrive box, prop and switch.

I have now sourced a Volvo "M410 gearbox with J type overdrive as fitted to late Volvo P1800E ES and 164" and I hope this is not going to be to difficult coupling it up to my B20. I assume that if I had sourced an M41 as apposed to an M410 then it might have gone together a little easier. Can anyone give any direction as to whats bits I need now that I have the M410?

Many thanks

Tony

You can only fit an 1800E M410, the 164 version won't bolt onto a B18/20 engine. The vast majority of ESs had M41 BTW