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#1 Speedo cable

Posted: Tue Nov 26, 2019 8:57 pm
by peters3103
Hi,
I want to replace my speedo cable as the needle jumps. I have removed and cleaned the old one which improved things but it’s now jumping again so points to the cable. My 3.8 has an all synchro gearbox fitted and the angle drive is on the drivers side of the box (RHD). Is the speedo angle drive on the opposite side on the Moss box? If so I’ll require a shorter cable. Would the 4.2 cable be suitable? I’d also like to stick to the grey outer.

Cheers
Pete

#2 Re: Speedo cable

Posted: Tue Nov 26, 2019 9:09 pm
by Gfhug
Pete, on my S2 with the all synchro box I used a new cable for the 2+2 as it is slightly longer and gives a gentler curve to the cable. You might wish to try the same.

Geoff

#3 Re: Speedo cable

Posted: Wed Nov 27, 2019 3:14 am
by peters3103
Geoff, yes I’ve read somewhere before (probably on this forum) about using a slightly longer cable. I’ll remove mine and measure it as a starting point. Thanks.

#4 Re: Speedo cable

Posted: Wed Nov 27, 2019 7:16 am
by chrisfell
Before you go any further, just check the timing of the “jumping”. On my car I replaced the cable, but found no improvement. Then I noticed that the jumping was exactly synchronous with the the mileometer. The tenths cylinder ticks every one sixtieth of a mile, exactly matching the jumping of the needle.

So.

I removed the speed head to apply Vaseline to the gears that drive the mileometer cylinders. Once lubricated the jumping disappeared.

#5 Re: Speedo cable

Posted: Wed Nov 27, 2019 8:55 pm
by peters3103
Thanks Chris, I’ll lubricate as you suggest but will also replace the cable while access is good (engine/gearbox out).

#6 Re: Speedo cable

Posted: Wed Nov 27, 2019 10:23 pm
by peters3103
I’ve removed my cable and it measures 50”. The part number is C24878 which is for all 4.2 E Types except 2+2. C17434 is the 3.8 cable which is 60” but I think this maybe a bit too long.

#7 Re: Speedo cable

Posted: Wed Nov 27, 2019 11:24 pm
by abowie
Pete I am in the same situation as you; RHD 3.8 with all synchro box.

I got a 60" cable and I have just looped it around the top of the box making sure none of the curves are too tight. I put a P clip on one of the top cover bolts to hold it in place.

Mind you I haven't actually driven this car yet :-) but it should work just fine.

#8 Re: Speedo cable

Posted: Thu Nov 28, 2019 3:37 am
by peters3103
Thanks Andrew, the 50” cable I have seemed to have a gentle curve from bulkhead to angle drive but does have a kink in it, perhaps it got jammed when the engine was removed previously. Might have been causing the jumpy needle. I’ve found a NOS 53” cable with apparently correct fittings and in the correct grey colour so I’ll buy and try that I think.

Cheers
Pete

#9 Re: Speedo cable

Posted: Thu Nov 28, 2019 9:17 am
by mgcjag
Hi Pete...if its NOS it could well be all sticky inside and need a good clean....check it out...Steve

#10 Re: Speedo cable

Posted: Thu Nov 28, 2019 9:25 pm
by peters3103
Good tip Steve, thanks. I did this with my old cable by spraying liberally with brake & parts cleaner, both cable and sheath (sheath in situ but disconnected both ends) then applied lithium spray grease. Any other tips re cleaning & lubricating?

#11 Re: Speedo cable

Posted: Thu Nov 28, 2019 10:02 pm
by mgcjag
There is a section in the service manual on the cable....too much oil can cause problems....off the top of my head think it says just 3 drops...Steve