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MG MGA - 5 Speed speedometer cable routing

If I'm reading the installation instructions correctly it's necessary to drill a hole in the tranny tunnel, hold the cable in position with a grommet, and route the cable under the carpet and through a hole in the toe board. To begin with, the grommet supplied doesn't seem likely to hold the speedo cable in position. The grommet I have looks remarkably like the one used in the valve cover. Is this right? I don't much like the routing idea for the cable either. Is there a better way to do this? I thought I read somewhere that there is a right angle adapter available. Input is appreciated.
Thanks,
Gerry
G T Foster

Gerry

I went down your route with the cable across the compartment. I ended up with a wavering speedo, partly due to poor inner/outer cable matching due to converting a Ford off-take shaft inner cable to the MGA instrument.

I strongly recommend going the extra mile with cost and fitting a right angle adapter to the the gearbox which allows you to use the original MGA cable up the inside of the tunnel. Many of us have done this modification with excellent results. Quite a lot in the archives.

Steve
Steve Gyles

I agree with Steve.

I made a removable panel in the tunnel as well, makes the whole exercise a great deal easier, otherwise the right angle adapter is a royal PITA
dominic clancy

I second Steves comments. Having invested in the 5 speed, the extra cost of a right angle adapter is not that much and you will be much happier with the results. Also, if you get the correct adapter, it'll compensate for the difference in speedo drive gearing so you don't have to get your speedo recalibrated.
Andy Bounsall

Guys,
I appreciate the advise. Where do I source one of these right-angle adapters?
Tx
Gerry
G T Foster

The company is called Speedograph Richfield. See here http://www.speedograph-richfield.com/html/rgb1030.html.

Check the archives to be sure, but I think it's the 1:1.4 ratio unit that will provide the required compensation for your MGA speedometer.
Andy Bounsall

Andy,
Thanks for the info. I will check the archives. Thought I did but apparently not the right words. Not available except from England? I'm curious, how does it attach to the tranny? Steve implies that the stock cable can be used, but their web site indicates a new cable must be purchased. Can you clarify?
Thanks,
Gerry
G T Foster

There is indeed a lot of info in the archives if you use the right words. Still, I haven't seen what holds the right angle drive in place although a "strain relief" was mentioned, it seemed to be for the cable.
Thanks,
Gerry
G T Foster

Questions, questions...
This removable panel I've seen discussed...what is this panel for? Do you install the transmission with the right angle adapter installed or do you put it on after the transmission is in the car? I prefer doing the engine and tranny as a unit, but I know there is a lot of "discussion" about this.
Cheers,
Gerry
G T Foster

Gerry

The normal out put from the 5-speed is a Ford fitting. Speedograph have a number of options available. The connecting end to the transmission is obviously a Ford fitting. However, if correctly specified, the out put end is an 'MGA'/Jageur/Smiths fitting, allowing you to use the original cable. Cable length is sometimes an issue. I found with my RHD car that the standard cable length was barely long enough. The longer cable (I believe standard on LHD) does the job just fine.

The problem with the Ford/MGA cable in the earlier days of the 5-speed conversion was an inner cable that was too small a cross section for the outer cable. This was because the Ford out-put shaft cable cross section was different to the MGA gearbox out-put shaft cable cross section. The supplier bodged a cable to fit. As a result, the inner cable tended to wind up and then release, causing significant speedo wander. I believe that Peter Gamble of Hi-Gear has now resolved the issue and supplies the correct cable for those who want one that crosses the cockpit.

Steve
Steve Gyles

Gerry

Just read your last. The problem with the right angle adapter is that it is very close to the transmission wall. It is almost impossible to fit with the gearbox and unmodified transmission tunnel in situ. There are probably 4 options:

1. Attach the right angle drive to the gearbox before fitting.
2. With the gearbox installed and transmission tunnel removed, fit the unit.
3. Cut an access panel into the transmission tunnel wall to allow room to fit/remove the unit when gearbox and tunnel are in place.
4. Grind a corner off the unit to allow it to be manoeuvred into place with Gearbox and tunnel in place. John Francis has done this and can supply details. Photos are also in the archive.

Steve
Steve Gyles

Gerry

Picture attached (looking vertical from below) of my right angle drive in place showing its closeness to the tunnel wall (almost touches). You can make out the outline of my access panel. I also fitted some sponge/soft rubber block between between the unit and panel wall.

Steve

Steve Gyles

Steve,
I appreciate your clarifications. Guess I'll machine the adaptor and remove the Tranny tunnel to be safe. Do you have machining dimensions? It appears that there is a circlip that holds the right angle adapter to the tranny. Is that correct?
Gerry
G T Foster

> It appears that there is a circlip that holds the right angle adapter to the tranny.

Yes, that's correct Gerry.
Andy Bounsall

Gerry

I didn't measure the part I machined but here is a photo of it. It was machined close to the brass fitting for the speedo cable take off (on the far side of photo). The fitting on the speedo cable is actually closer to the tunnel than the gearbox. Hope you can see what I mean. The machined angle is approximately parallel with the tunnel when fitted to the gearbox so gives maximum clearance.

Circlip to gearbox is also shown.

John



John Francis

PS

Speedograph can also make a cable which is 4" longer (whatever dimension you want) than the original and with the correct grey sleeve. Obviously I needed this for a RHD car, LHD will be slightly different but the gearbox take off point is further back on the 5 speed box than the standard by about 4".
John Francis

Standard speedo cable for a LHD MGA is 66". I used a 69" cable, Moss p/n 331-190, for 62-67 MGB w/OD. It works just right.
Andy Bounsall

Thanks for you inputs. As always, very helpful.
Cheers,
Gerry
G T Foster

This thread was discussed between 28/07/2011 and 03/08/2011

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