Speedo

Thanks just trying to get to bottom of it keep stopping. Have replaced angle drive twice. Cable seems free needle moves when I twist the cable. Angle drive has copper washer at gearbox union. I don't know what to check next!
 
there are 2 angle drives on my rover p6b. replaced cable and checked bot drives no faults found . lubricated both drives and cable . speedo works but reads slower than actual road speed ! wondering if tyres are correct size now ? seems odd it works but keeps stopping .form description sounds as though cable isn't driving speed unit fully. Is cable sticking through enough for full contact? we checked cabe at speedo end with fingers when its in gearbox ? should be stiff and no turning ..do not force. if..cable isn't engaging fully in speedo head it may be creating a friction ..enough to drive a bit bit not keep going etc.
 
All problem now resolved. I decided to take angle drive apart. Its very simple just two circlips. Once they are removed the two gears come out. The one that goes into the speedo drive has a square drive shaft that goes through one of the gears. This was where the problem was. The shaft was spinning in the gear. I was able to pull the drive completely out. I assume that this should be an interference fit. However after cleaning all the bits of any oil I used a little bit of Loctite super glue gel. I find this better as it stays where you want it. After 30 seconds it sets. Now the shaft is fixed in the gear. I reassembled the angle drive. Left it for another hour to cure properly refitted it to gearbox refitted the cable took it for a little drive around the block and hey presto speedo is working again. I am not sure if the glue will last only time will tell. If it fails again I will try solder. One thing I did notice was the speedo was steady now no fluctuation. I took the other speedo drive I have apart too just to see if that does the same. It does spin in the gear also. However the shaft did not come out. I will look into this one further when I have more time. Hope this helps others who may suffer the same problem.
 
Speedo needle started to bounce recently, hint of problem to come and it did, speedo stopped working. Having removed dash and instrument I removed the inner cable to find a fairly clean break about 2ins from the gearbox end. I removed the angle drive from the speedo head, all well there, smooth a silk. Got to the gearbox end and found broken end of the inner cable. which now makes very useful tool for checking the angle drives and the speedo itself. BUT, I am having difficulty getting the angle drive off the gearbox. Before I go searching for tools, such as small mole wrench, has anyone got any advice? Thinking about the break about where the break is, can it have been a simple cable failure and not caused by jammed angle drive? Any ideas would be very welcome. ( and it would happen just s Paul at Get Smart is moving his business over the river into Wales!)
 
If the angle drive had jammed at the G.box end it wouldn't break the cable. I suspect its a poorly routed cable that has caused the inner to break or its just worn out after so many years use . I would leave the angle drive and just replace the cable making sure its routed correctly and is not strained when fitting. Had the gearbox been removed previously ? Straines or sharp curves are a killer for speedo. cables
 
Last edited:
Hi, Also make sure any cable supports are not too tight as it can 'neck' the cable and break the inner. It doesn't take much.

Colin
 
Thanks Colin and roverp480, good to have my thoughts confirmed! Attempting to move the cable has met with strong resistance, suggestive of a hard bend or summat. Excellent weather for outside work! BTW, bonus is access to the dash lights, only five working! Replacement LEDs on their way.
Tony M
 
The break in the inner cable has been caused by damage to the outer, by what means I know not. Having proved that the inner cable was free from the speedo to the break point, inserting it from the gbox end met with resistance at the damaged point; so any idea of cheating by simply replacing the inner went straight out of the window! However, trying to extract the outer cable met with strong resistance and no way would the connectors at either end clear whatever was holding it. OK, I cut off connector and pulled, and out it came. Fine, now just re-route the new cable and all will be fine, right? Wrong! No way can I find a path to the gearbox drive. Looks like a while before I am back on the road.
Meanwhile, I have replaced all thirteen instrument/warning light bulbs, lots of fiddling but great result.
 
I found path to gearbox form dashboard was fiddly and removed radio speaker blanking grille to gain access. with much wriggling and probing my cable did manage to get from dashboard end down to gearbox section. then fitted to gear box angle drive. attention back to speedo end. now carefully. connected .road tested . shows stable speeds but still. getting. slight noise as though 'sticking' so wriggled cable and pushed back and forth ( wont say if I was driving lol) and now all very quiet with a real effort to hear any noise form cable as other road and engine noises. now drown anything out . good luck with yours. I cannot get speedo trip to work and checking cable it seems it has been bent at joint where it meets speedo section. can't be bothered to sort so will check agin when off road end of year when season ends.
 
Where did August go?? Finally got back to sorting out the speedo cable and with help from one of the boys managed to find a route without nasty bends or obstructions. Result is perfect working speedo. The needle is rock steady and accurate. Thanks classicalgreen for your encouragement.
The instrument lighting with new LED bulbs is excellent.
Next operation is to fit door speakers for my updated Voxson Stereo 8, the radio gubbins has been replaced by fitting a Aurora Design FMR-2.7. The conversion was carried out by Adrian James in Paulton, sound quality is excellent and I may live long enough to be able to learn to work it properly?
 
Back
Top