New speedo cable needed

[KKson]

Hi all, and almost happy New Year! Was having a fettle with the Wedge today in readiness to a drive to Shelsley tomorrow for the New Years day run and cholesterol fueled breakfast - the speedo has been somewhat erratic of late, jumping around and recording quite optimistic speeds even when I know I'm only doing 30mph. Anyway took the speedo out and the end of the speedo cable has parted company with the end fitting so the cable is twisted and putting pressure on the internals of the speedo. I've had a play with a load of duct tape and managed to secure the screwed connection back on to the cable temporarily. The speedo now reads the correct speed but there's a noticable satellite delay in the speedo recording the speed and when I stop it still shows 20mph. If I slacked the screwed speedo connection on the back then the needle returns to zero.

I'm assuming it's just the buggered cable that's the issue. I've not had a thorough look yet but from the back of the speedo where does the cable run through? It is through the gearbox cover and on to an angle drive on the gearbox? I did read a post about a 400SE with an intermediate transfer box so one cable from speedo to engine bay inner wing and then a second cable from there to the 'box. I've certainly not seen anything similar in my engine bay but then again the bulkhead is off a 400SE and not the standard 350i, due to the SEAC style dash board.

I see from previous posts that most have had replacement cables from Cable-Tec. I'm assuming that the cable is not an "off-the-shelf" item but was a special for TVR? Does anyone know if it was used on any other TVR's?

Thanks and a safe and healthy 2015 to you all.

[The Hatter]

My SEAC and 350i both use the same speedo cable/route; straight forward through the bulkhead grommet near the clutch master cylinder, then in a big loop across the back of the engine and down to the nearside rear of the geearbox extension. It runs pretty close to the exhaust so may have been cooked.

[KKson]

Okay thanks for that. I'll get a new one ordered up on Friday. Cheers.

[Jack Valiant]

Land Rover Discovery 1 V8 EFi and correct coloured gear wheel (seperate) to suit the box / gearing you have in the LT77 box. There are two types (1) is a single cable and (2) a 2 piece

Chris

[wooly350i]

We sent two cables to cable-tec for them to copy with instruction to increase length on one, came back within a week both perfect for each wedge, they did need everything though to copy to be sure they were correct, cable and any broken off ends. Wooly.

[RCK974X]

As a temporary bodge job, I used electrical 'heat shrink' tubing on mine, which is still going fine after 2 years....

used it on speedo end when it had split and come off the cable outer....

Just saying this as an idea if you're stuck....

[GV]

My Speedo has been playing up - but I am thinking about going electronic which will mean new gauges all round. Will probably send my cable off for replacement first though.

[bradderztvr]

Keith, so when the Rozzers stop you and say...."Do you know how fast you were going sir"... You can honestly reply "Haven't got a clue"... Happy New Year.
Ps. It was an interesting experience with the Inspector driving back today !

[KKson]

Despite the roof down Emms was asleep pretty much the whole journey, after we had to get the Wedges push started. Embarrassing....

[Wedg1e]

The usual reason for a 2-piece cable on the LT77 is to allow incorporation of the pulse generator used to feed speed info to the ECU on a 14CUX-based system, whilst retaining a cable-driven speedo.
The later SD1s used an electronic pulse generator in the side of the gearbox (replacing the cable drive) to feed the electronic dashboard they had fitted.
I used the 2-piece idea and the same pulse generator to drive the cruise control on my car; I sent the old single cable to Speedy Cables and they produced a 2-piece version that puts the pulse generator behind the dashboard rather than out in the engine bay.