Help required to fit overdrive gearbox

[WPR678B]

Looks like a bit of cutting and welding is on the cards then when i reach that hurdle. Thanks for the heads up!

[940_Turbo]

Originally Posted by WPR678B

Looks like a bit of cutting and welding is on the cards then when i reach that hurdle. Thanks for the heads up!

I dare say I'll have a 140 OD cross member if you get stuck.

[WPR678B]

Originally Posted by 940_Turbo

I dare say I'll have a 140 OD cross member if you get stuck.

PM on the way!

[tonydgray]

Thanks to everyone for your input, lots of it which is great.

WPR678B - yep its good we are both looking at this at the same time, hopefully it won't be too long before mine is all bolted up! Interesting what you are saying about the different overdrive rubber, I have the standard non-overdrive one at the moment so that may be something I will have to pick up.

john_h - photos would be great to get an idea of how it needs to be altered. If you also have the rubber mounting and the bracket the bolts directly to the gearbox that would be great to see as well.

I suppose the one difference with mine is that I am swapping from an M40 to an M410 so I'm also not sure of how the cross member differs with the different gearboxes as well as the overdrive. I managed to find a picture of an M410 where you can just about make out the little gearbox bracket along with the rubber mounting which does help a bit.

Unfortunately all was not well on the propshaft and overdrive flange on the weekend. The flange that sent was supposed to be 60mm deep and this was taken into account when giving the propshaft guy the dimensions of how much to shorten the prop. When the flange arrived it was 45mm deep instead of the 60mm so I'm 15mm short. I have to make the decision today of whether to get the prop guy to do what is required (increase the size of my front flange on my prop and make it the same length) or wait and see if I can get a 60mm O/D flange from the supplier.

Thanks again

Tony

[tonydgray]

Oh I forgot to ask. Does anyone know the thread size for the inhibitor switch in the cover. I have to drill and tap my cover to fit it but I've not got any taps at the moment so have to pick something up. Thinking about it that hole is pretty large to drill so I might have to pick up a larger drill bit as well!

Cheers

Tony

[Derek UK]

Looks like wheels breed in your garage.............

[tonydgray]

Originally Posted by Derek UK

Looks like wheels breed in your garage.............

Shame its not my garage :-) I'd sell those wheels to fund the overdrive conversion!! Google sourced the pic for me :-)

[REGAL 144]

Hi Tony,
I am puzzled why you have not got an inhibiter switch already fitted to your overdrive box, I was given to understand it is essential to avoid wrecking the overdrive when in reverse. The previous picture with all the wheels shows its location though maybe like me your'e missing the reverse switch? A little more info when wiring up, the workshop manuals are quite brief I think like me you will be modifying the loom from DL pattern to GL for overdrive. Behind the speedo head there is round multi-plug with female connectors 1,2, miss a few upto 11, No_ 12 is the connector point for the O D warning light, though there is nothing in the hole you have to make up a substitute with a wired bullet connector modified to fit the pin like the rest. A mate of mine suggested that this be wired piggy-back to the live feed on the overdrive selonoid so only illuminating when engaged. I,m sure it has been suggested elsewhere when/if you need to lengthen your speedo cable Speedy Cables of Swansea provided me with a very good service.Hope this helps a bit more,sorry to ramble on.
Best Regards
Bryan

[tonydgray]

Thanks Bryan, that's all good information.

I'm using the gearbox top cover off my old m40 box as it has the original reverse light switch that I think is used for the seat belt warning light as well. I want to keep the wiring as standard for this to be honest and the m40 cover has a raised bit in the casting indicating exactly where the inhibitor switch goes. The inhibitor switch is now fitted but I have yet to test it so fingers crossed.

That's a great bit of info regarding the number 12 connector for the overdrive indicator light, I'll have to look into that. I found some good information about the numerous wiring options here:

http://www.sw-em.com/OD_Retrofitting.htm#OD%20Wiring

I think I've decided on and interim wiring option of "OD Wiring 3" and then altering it to "OD Wiring 4" when I have sourced the column switch, relay etc.

Interesting what you say about the speedo cable. I do need to get one as mine is too short now. Did you send your original off to be lengthened or did they just send you the correct new one?

Thanks for you help, cheers Tony

[laptoprob]

Hi Tony,
I've changed a '73 144 and my '70 145 from M40 to M41. The first with a J-type, the second with a D-type. Just rerouted the speedo cable on both cars, no problem in connecting. Both are directly coupled, no angled drive at the OD end.

cheers, Rob