MG-Cars.net

Welcome to our resource for MG Car Information.

Recommendations

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG Midget and Sprite Technical - triumph d type gearbox fit or not

Dear All,

I am considering a purchase option for a Triumph 1500 gearbox d type with overdrive to fit to my 1500 midget is this compatable with this car or will i have to mess about with the transmission tunnel.

I believe that originally this gearbox was taken from a late triumph spitfire 1V if this helps

regards

Douglas
df mccabe

Various mods are required to fit the overdrive box including removing and replacing the crossmember. Quite a big job but a good improvement on standard. I think someone does a kit of bits with instructions. I can't remember which O/D i fitted but it did come from a Spitfire

Cheers Carl
C Bintcliffe

Carl many thanks,

I know that i will need to change the speedocable, crossmember and prop, but the eliment i am struglling to assess is if the J type is the one that is the easier to fit or the d type.

anyone be of helps out there?

regards

Douglas
df mccabe

Douglas,

I am a wee bit confused by your post.

Initially you say it's a 'box plus O/D from a 1500, then you say it's from a late Spitfire MkIV.

You then say it is a 'D Type' O/D.



The UK spec 1500 Spitfires had the 'Single rail' gearbox with a 23 spline input shaft.

Mk IV Spitfires had the '3 rail' gearbox with a 10 spline input shaft.

(Early US export 1500s had a 3 rail box with a different flywheel to crank fixing and some of these have been re-imported so beware!)


The 3 rail box is easily identifiable because it has a top cover extension, in which runs the gear lever selector shaft. The single rail box lacks this extension - the selector shaft exits the back of the box and runs to a housing just forward of the output shaft flange.

If it is a 3 rail box it will fit but it is a lot more work since you will need a different clutch, modified flywheel, and you may well need to modify the top of the transmission tunnel around where the selector shaft extension lies. Albeit the 3 rail box is far sweeter and lighter than the later single rail type.

If it is a single rail box it is a far easier swap because it is essentially the same box as the Midget 1500 (albeit the gear ratios are different (shorter 1st and 2nd but taller 3rd and 4th).

HOWEVER, during the production run of the single rail box BL changed the input shaft oil seal from a scroll type (early) to a lip type (late). The two are not directly compatible; that is to say you have to match the correct front cover (and seal if applicable) to the input shaft type you have in order for the box to fit to the bellhousing (the cover [and seal if applicable] press into the rear face of the bell housing).



With regards to overdrives:

ALL 1500 Spitfires (where fitted) had the 'J Type' O/D.

Spitfire MkIV's were fitted with the J Type from Commission Number FH6001, prior to that they had the 'D Type' O/D.

The easy way to check is that on the J Type the solenoid is on the left (looking forward) and on the D Type it is on the right close to the speedo drive.


The D Type O/D will NOT fit a single rail box without SERIOUS work (and is a poorer unit than the J Type anyway). Thus if it IS a D Type then it is almost 100% certain that the box is a 3 rail and you have your work cut out for the reasons explained above.


Also note that a single rail box with O/D will require different mountings from a non O/D box - it s possible to modify the Spitfire mountings to fit the Midget.


I would suggest you get the Moss catalogues for both the Midget and Spitfire as well as the Rimmer Brothers Spitfire catalogue - they have some great exploded drawings that will show you what I have been trying to explain.



For reference:

This is a 3 rail gear box:

http://cgi.ebay.co.uk/TRIUMPH-SPITFIRE-GEARBOX-NON-OVERDRIVE_W0QQitemZ170383844306QQcmdZViewItemQQptZUK_CarsParts_Vehicles_CarParts_SM?hash=item27abab23d2&_trksid=p3286.c0.m14


This is a single rail gearbox/:

http://cgi.ebay.co.uk/MG-MIDGET-1500-TRIUMPH-SPITFIRE-GEARBOX_W0QQitemZ190330816606QQcmdZViewItemQQptZUK_CarsParts_Vehicles_CarParts_SM?hash=item2c5099c85e&_trksid=p3286.c0.m14

Deborah Evans

Thanks the details are fantastic and between your comments and the advise from the owners club my options are single rail with O/D or type nine modifaction and will steer clear of this oportunity

regards

Douglas
df mccabe

This thread was discussed between 18/09/2009 and 20/09/2009

MG Midget and Sprite Technical index

This thread is from the archive. The Live MG Midget and Sprite Technical BBS is active now.