Disco 1 Speedo needle issues

Hi guys, I've got an issue with my speedo on my 3.9 V8 D1. It has started to intermittently drop to zero, especially when it reads around 60 mph it'll just drop. Sometimes it bounces on the way down other times it falls like a stone.

I could return to the car within hours and it'll pick up again, other times it's a few tries and it'll pick up ss normal,

It needs sorted as it went to 0 on the motorway to Edinburgh, my wife had to download a speedo app for the rest of the journey,

Cheers

Craig

I would be interested to hear the jurys verdict too...
...my RRC 3.5L V8 has a speedo-needle-bounce issue, below 20 mph.

kurgan said:

Hi guys, I've got an issue with my speedo on my 3.9 V8 D1. It has started to intermittently drop to zero, especially when it reads around 60 mph it'll just drop. Sometimes it bounces on the way down other times it falls like a stone.

I could return to the car within hours and it'll pick up again, other times it's a few tries and it'll pick up ss normal,

It needs sorted as it went to 0 on the motorway to Edinburgh, my wife had to download a speedo app for the rest of the journey,

Cheers

Craig

Click to expand...

Loose/dirty electrical connection somewhere, either at the transceiver on the transfer box, or in the dash pod I would think.

Dizzy, I had assumed that both the D1 and the RRC had mechanical speedos....you would know, having owned both for a long time, though!
Disco-write-off-crash head injuries have done no good for my memory...

shocker said:

I would be interested to hear the jurys verdict too...
...my RRC 3.5L V8 has a speedo-needle-bounce issue, below 20 mph.

Click to expand...

Your needle bouncing is probably due to the angle drive on the back of the speedo. They can fail.

It's working again today, for how long who knows.!!!

Aaah, yes! I recall reading about that very thing, now that you mention it. Thanks Craig. I had discounted it (rashly) as it only appears at low speed...though just what I was using for logic at the time I couldnt say. Probably just making it up to show off to myself and feel clever. For once.
Hope you get a proper answer off someone soon mate

My 3.5 RR speedo used to bounce at low speeds something like 20mph when slowing down in traffic etc, the opinion at the time was that oil or grease had moved up the drive cable into the speedo head, so that's how it stayed for the remaining seven years of ownership, easy when one doesn't look at the speedo at low speeds.

I must say that I agree with your speedo-watching technique, viz-a-vi RRC. I rarely look at the speedo, making more use of the wine of the transfer box along with occasional glances at the rev counter. Hence I have no idea how long this needle bounce has been going on. I only noticed it after I got new tyres all round and thus had that much less to worry about, so (in the time-honoured LR fashion) noticed a new problem to fret over.

discool said:

Loose/dirty electrical connection somewhere, either at the transceiver on the transfer box, or in the dash pod I would think.

Click to expand...

+1 - @kurgan - my D1 had the same issue - in my case it was the transducer on the transfer box which had let the smoke out - a new one cured the problem - but it's also worth checking the connections in the instrument cluster for verdigris...