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MG Midget and Sprite Technical - Speedo cable sort out

My speedo and mileometer have not been working and PO had new speedo with 000000 miles on so swapped it today. No effect, 0000000 miles and no miles an hour.
So; have read my books and searched archive and can find:
A ref to putting some packing in the end of the cable to make the cable work. This does not say 1500 on the entry in the archive so having looked at the speedo end of the cable and gone !? has anyone any experience of this on a 1500?
I have no pics or descriptions of looking at the gearbox end or how to replace a cable on a 1500. Could do with knowing if I need to jack up car or if its accessible from in the car?
Also is there anything I may need to do the job out of the ordinary? have spanners etc. but is there a special tool required?
Someones decription of what they did to change a cable on a 1500 would be really good and helpful.

Just another one of those things that crawled out the woodwork that I have not done before. Its the last legal thing to 'fix again' appart from the dodgy horn that will be replaced tomorrow. Talk about a shake down, the more shaking you do, the more shakes out! :-)
Dave Squire

Dave,

if the 1500 set up is anything like similar to the A series, then it may be a broken speedo cable.
Not sure if there is a test you can do with it in situ (short of jacking the rear up, running the car in gear and checking to see if the cable rotates, although I can't really recommend this approach) but no doubt someone will be along with a more appropriate solution.

Jeremy

Jeremy 3

<<Talk about a shake down, the more shaking you do, the more shakes out!>>

It seems that's what owning one of these cars is all about! I started off replacing a worn rear wire wheel hub extension and finished up replacing the rear axle casing and redoing a leak on the diff pinion seal which I'm sure wasn't there before! (... and replacing both hub bearings, seals and brake shoes.....).

As long as you see it as "enjoyable" I guess that is all that matters. If it's a P.I.T.A. then I guess that's when to give up. It will also be "expensive".
G Williams (Graeme)

Dave,

The 1500 cable is held in place on the gearbox with a small clamp bolted into the gearbox.
Hav'nt been under a 1500 for a while but seem to remember it was accessible O.K.

As Jeremy has said could well be a broken cable - used to be able to buy just inners - not listed now, only complete cables. They are squared at both ends and just push into the sockets on the speedo head/box end.

I have previously jacked the car on axle stands + blocked front wheels and gently put in gear and at very low revs checked if the cable rotated i.e gearbox pinnion O.K / broken cable etc (Elf and safety warning alert).

Replacement is just routing through and connecting.

R.
richard boobier

it's very easy to test the cable, disconnect it, hang it from speedo or dash with long tie-wrap and if it turns as you drive the car then you know some sort of drive is making it to the speedo end
Nigel Atkins

Looks like speedo cable end could be missing at speedo end (its hollow and round in there. I will drive like Nigel says in the morning and see what happens. If its turning that could explain why someone in the archive put something in the cable to gain purchase at the end of the cable to drive the speedo.

Thanks all, hopefully fix tomorrow, and if not then tuesday.
Dave Squire

Hollow at the speedo end?
Can't you see a square pin which engages in the back of the speedo? It's that bit that drives the speedo and what you need to see turning when you do Nigel's test. It should be level with, if not proud of, the locking ring which grips the back of the speedo.

On the earlier Sprigets there is a rubber plug in the tunnel which is there to help gearbox top up but also lets you see the speedo connection to the gearbox. Might be one on your model?

Access to the connection on the gearbox to do any work is one of those 'orrible jobs because getting the car high enough on jacks/stands to be able to get underneath to see/reach has a slightly worrying feel about it. Getting under the middle of the chasis always seems the most awkward! Just use blocks, jacks and stands everywhere to be safe! Or put it on an hydraulic garage ramp.
G Williams (Graeme)

Looks like thats the problem then Graeme; no square bit. Will look closer when the light improves today but looks round and short of the locking ring in there at first glance.

No worries about car up, still have the four axel stands from welding underneath, and the baulks of timber to go with them. Now I know its do able and how it goes from crawling under its not so bad.

Car sounded better again yesterday so its all going in the right direction.

Thanks all.
Dave Squire

Dave,
what you're going through is pretty standard fare, as you've found the more you drive it the better it gets but the more it exposes things that need attention

also IIRC the car recently passed its MoT proving it to be a (recent) historical document

I hope potential and new owners see this thread as it's an example of what they need to be aware of - but as you've found the more you drive it and carry out the necessary work the better the car gets and the less there is to do on the car

keep going, if you can get through the winter the spring and summer will be a doodle and the car better and even more enjoyable
Nigel Atkins

Absolutely Nigel.

Rigged hand drill to old speedo today and yes it works. Looked in end of cable at speedo end in daylight and cannot see an inner drive part to it. Two of us agree it must be broken and someone previously assumed it was the speedo broke and spent 10 years ago the then equivalent of ....... £80 speculating.
Ordered drive cable part from sussex with the innevitable 'other bits' that are next on the list like drivers door 1/4 light to widscreen seal that has never fitted properly and probably caused previous 1/4 light frame to break through over vibration on door shutting.

:-) all good fun.
Dave Squire

Thanks for all your help fellows, new speedo cable arrived allowing me to compare and yes the drive pin in the existing cable is missing at the speedo end. Just need to get the car up and crawl underneath and a two minute job. Ho Ho.
Anyways thanks again it will be done soon. Old speedo will be back in and itl be an uncle bobs.
Dave Squire

Two minutes = half an hour!
G Williams (Graeme)

You got the coconut Graeme. Cable on gearbox end and through bulkhead, coffe and time to warm tootsies, then probably another 20 mins.

SWMBO always says I am wrong and what can I say? She's been saying it for 39 years so you would think it would have sunk in by now wouldn't you?
Dave Squire

OK so the speedo was knackered as well so took a bit longer cos of replacing that.All works fine now.

More driving - yippeeee.

Thanks all.
Dave Squire

Dave: it's a good feeling when you can tick something off the list!
G Williams (Graeme)

drive on your rev counter until you know how accurate your speedo is :D
Nigel Atkins

...or on sat-nav
Dave O'Neill2

A good and timely reminder. I have phone speed reading capability so will check with that. As Nigel says my tacho seems to have been a good guide so far.

Thanks all. I hate paying money for putting in more tax machines.
Dave Squire

It all checks out, speedo at low speeds is exact with phone read out and the speedo at 70 is showing 68 on the phone. Tacho matches for standard 78 diff as well so well chuffed it is all original spec. Just a shame the mileometer is wrong cos I think it could have been correct from new.
Do I have to notify dvla of replacement mileometer or just notify it has been replaced on selling? (I am not selling a car that is making me smile by the way).

Thanks all, can't wait for a longer run later.
Dave Squire

Dave,
why not just wind your speedo on to the correct mileage, you could practice on the old speedo
Nigel Atkins

Good idea Nigel, it would be nice to have it correct.

Went to a clients 20 miles away today so 40 mile trip mixed single and dual carriageway with some urban city driving at the other end; the engine is loosening up nicely and the power is coming back in it. Easy keeping up with small moderns and accelerating faster than a lot of them.

On return, top heater hose has sprung leak so I now know where that previous slow water loss probably was. Its split the rubber from deterioration. Fairly easy replace on the top of the engine and heater tubes. Then maybe the heater might work!
Dave Squire

two things I've put many times -

a) watch out for rubbish rubber (including hoses) (if the hose is deteriorated why didn't you change it before?)

b) I have a simple effective method of cleaning the coolant/heating systems (sneered at many times here but my heater is very hot), it'd best been done when you had the engine out but still can be done

cooling is very important to car engines especially it seems the midget 1500 so much so that many seem to need an addition to the secondary cooling system (oil) of a oil cooler (almost all without a thermostat so over cooling the oil at this time of year as the oil cooler isn't covered)

watch that you get the air out of the system when changing hose - clear instructions for refilling are in a certain bedside book
Nigel Atkins

Winding an old speedo on would be very slow using a drill. Lots of information on the 'net about stripping the speedo and resetting the digits.

A speedo needs 1400 revs per mile (as a general figure), so if you have a 1500 rpm drill, thats roughly 1 mile/min to wind on the mileometer. Much faster than that and you could damage the speedometer section.
G Williams (Graeme)

This thread was discussed between 03/02/2013 and 08/02/2013

MG Midget and Sprite Technical index

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