The MGA With An Attitude

Installing the Nissan 5-speed gearbox in the MGA, originally found in the Nissan 240 cars. Pictures and technical content of this article are courtesy of Paul Urquhart (see e-mail contact below).

Paul Urquhart Why put a 5 speed in a 40-year-old car (MGA)? There are a number of reasons to do it and a number of reasons not to. For me it was to make the car a better road car and to lower engine RPM at highway speeds. There are kits sold to do this change so I am not the first to do it.

Over the past two years I have been working on putting a 5 Speed transmission in my MGA and have done a lot of work to do that. The project is almost done as of this date and I am in the testing phase now.
Original MGA gearbox

Standard MGA gearbox

The transmission that I chose is out of a Nissan 240 SX "89" it is just about the size of the MGA tranny it has a built in bell housing and runs a 12" flywheel the input shaft is the correct length and size. Other good points are that the starter and clutch lever are almost in the right place on the right side. I also used the Nissan flywheel and clutch but had to do some machine work on the flywheel to get it to fit the MG crankshaft. The making of the engine back plate was one of the biggest challenges and has the most time invested into it. Finding a starter to fit is the next challenge that took a lot of research but one was found and it works well. The rest of the work is in getting it in the car making some room and getting it all lined up to fit in the drive shaft.
Nissan 5-speed gearbox

Nissan 5-speed gearbox and MGA engine, mounted in MGA frame

Only a few modifications have had to be done on the frame for the trans mount and the trans tunnel had to opened up on the right side to make room for the trans. In all the fit into the car was not that bad. I will be installing a new electronic speedometer to work with the new transmission and the change over will be complete and the highway driving will start.

I would like to know if any of you would be interested in putting a 5 speed in your car? How much would you be willing to pay for the main parts as a kit? Steve Merical and I will be putting this set up into his "A" soon. Let me know if you have some interest or questions I will be more than happy to try to answer them all.

Paul Urquhart -
Modified opening top and side of tunnel
Open top & side of tunnel
Fiberglas top cover
Fiberglas top cover
Steel side cover with slight bulge
Steel side cover with slight bulge
Finished interior in MGA
Finished interior in MGA
Flywheel & pressure plate - Nissan & MGA
Flywheel & pressure plate
Nissan left - MGA right
Machined engine rear plate
Machined engine rear plate adapts
Nissan bellhousing to MGA engine

          MGA       MGA      MGB 3sync  MGB 3sync  MGB 4sync  Nissan
          Standard  Close    Standard   Close      Standard    240
          Trans     Ratio    Trans      Ratio      Trans      Trans
1st gear  3.64      2.54     3.64       2.44       3.44/3.33* 3.321
2nd gear  2.21      1.62     2.21       1.62       2.167      1.902
3rd gear  1.37      1.27     1.37       1.27       1.382      1.308
4th gear  1.000     1.000    1.000      1.000      1.000      1.000
5th gear   --        --       .802       --         .82        .759
                           Type D OD             Type LH OD
                                         * = post 1978 1st gear

Addendum, February 2003:
1. I used the total Nissan clutch, throw out bearing , release arm, and flywheel. Did use the MG slave cylinder had to make a new rod to get the right movement.
2. The Starter is a Toyota gear reduction. (STARLET).
3. The prop shaft is the Nissan modified to use a standard MG type flange. The Drive shaft is custom made 29" solid shaft no expansion joint.
4. As for the speedometer, the Nissan has an electric signal generator with a two wire output. The electronic speedometer will work with the out put and has a calibration feature so any gear changes in the rear end or tire size can be changed with no problem. I could have worked on a cable drive but I needed a new speedometer any way. I can send you more pictures and give you a more detailed write up.

Yes I would like to see if I could sell some of the parts that you need to do this. I have the CAD drawing for the engine plate and can get them lasered for about $50 each and then machined for about $100 each, if I do 4 at a time. I have over $900 invested in parts, no estimate on the time that I have spent, and most of the machining has been free to get the set up in my car.

Will be doing another one on Steve's car soon. We still need a clutch and fly wheel to get started on his. Right now I am trying to get some miles on it all to see if any problems show up. Working on a small oil leak now but it not a problem. I put in a tranny out of a junker with 140,000 miles on it I think and so far it shifts fine and is quit and all sychronizers (5) work great. The ratios seam to work out great.

Paul Urquhart -

Addendum, December 2003:
On 01 December 2006 at 19:00:46 UK time Steve Merical wrote:
Went digging through some old files to confirm the cost. I did this a couple years back and at that time it cost me $1,150 US$. I pulled all the bits I needed from a 240sx in a salvage yard. It had 100K on the ODO but from my understanding these trannies are very hardy. Nissan was originally going to be mating a larger HP engine than they ended up using for the 240sx. Anyway, I haven't had a problem with the used unit.

Some of the more expensive bits were:
Nissan Clutch pack
Drive shaft mod. (about $300)
Different Starter
VDO speedometer ($120)
Engine Plate ??

This is NOT a kit that comes where everything comes in a nice box. The guy that designed it (Paul U.) figured out how to do it. He made a special engine back plate to mate the Nissan tranny to the MGA engine. You need to get that item from him. He gave me a parts list of what else I needed. All the other stuff you can pick up at the scrap yard yourself or buy on-line/auto store. If you enjoy pulling your engine or at least aren't intimidated by that, this shouldn't be a problem for you to install. If you've never pulled an engine before this wouldn't be a good time to start.

Cheers, - Steve - '58 MGA - '62 Mk2
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