speedo ceased to work?

[Pat the Plumber]

having read most of the past comments on previous problems to do with the speedo, the car was promtly put up on axel stands and proceeded to check the very awkward positioned elbow. the cable wouldn't come apart from the elbow initially until a little more brute force was applied, out came the battery drill to check if the speedo worked, 80mph was showing on the clock. that cancelled out the clock and the cable.

onto the wonderfully positioned elbow. at this point nobody told me not to take the "cir-clip" out, too late. this revealed the brass top hat, with another pin protruding from the gearbox.

should the pin in t he gearbox come out?

a small srew driver into the elbow and twist would cancell out the elbow. HELP is now required, back together including the clip,still no speedo.....?

 

[mav]

Pat,

 

Perhaps the plastic (?) gear inside the drive has failed somehow...

[micksmetafors]

Just had to change my angle drive unit. There wasn't enough metal left in it to engage the squared off quill pin.

 

Good luck

 

 

[Pat the Plumber]

so do i get another angle part, or, and a new plastic pin from caterham . any more ideas

[micksmetafors]

To check if the plastic drive gear is OK put the quill pin (square section formed from wire into the sqaure socket in the end of the plastic gear.If it turns in it then you'll need the gear changing. if not, it's probabaly the angle drive that needs attention.

They're not the greatest strength item but at least it's not too tricky to change over.

 

 

[Pat the Plumber]

do i get that from caterham, the angled elbow.

with regards to the pin is it suppose to come out, it spins ok, but didn't seem to want to serarate from the gearbox. there is movement in and out but only a little

[JP]

The short length of speedo cable from the g'box the the angle drive broke in mine - you might need to grasp it with a pair of pliers to pull it out.

It should be about 1.5" in length if it is in one piece.

I get the impression that the holes in the g'box and the angle drive are not perfectly in line , stressing the cable which causes it to break eventually.

It's cheap part - about £1 check this first.

[Nigel Riches]

Pat, with reference to your comment about the pin not wanting to seperate from the gearbox, and it spins freely, well this indicates the drive gear in the tail housing has failed, you should not be able to turn the little short drive pin in the gearbox, as this is a worm and nut drive, sounds as if the plastic gear (nut) has stripped teeth, or the gear on the output shaft (worm) has come adrift, the former can be repaired in situ, with several blooded knuckles, the latter will be a gearbox out job, sorry to be the bearer of bad news. Nigel.

 

1982. 5 speed, clamshells. B.R.G / Ali. The True Colours.

 

PS try a new short quill drive in the angle drive, and apply the battery drill to turn it, check the speedo indicates, if it does, bad luck.

 

Edited by - nigelriches on 3 May 2005 09:16:37

[Pat the Plumber]

should i get pliers on the pin and pull it out, or should it not be that hard to get out. do i need to get the "cir-clip" back out and then loose my rag trying to get the chuffing thing back in.

[oldbutnotslow]

Pat if you need a quill I have a new one that you can have

 

Grant

 

Black and stone chip.

Engine now run in

here

[Chelspeed]

With the back wheels in the air turn the wheel(s) or start the engine and put it in gear (need good secure stands!) and see if the square section of cable sticking out of the gearbox turns. If it doesn't then it's either the plastic gear or the drive gear.

 

My experience of this problem is that the fault is usually the metal drive gear on the gearbox output shaft is a loose fit and moves along the shaft until it comes out of mesh with the plastic gear. As said before gearbox out job to fix. So don't bother, get a pushbike speedo to stay legal until the box is next out anyway.

 

Don't spend £50 on a new gearbox angle drive until you know it isn't the above.

[Pat the Plumber]

have jacked the car up and revved it hard through the gears, only joking. l think its good news as the spindle(pin) is spinning.

as i'm a complete novice would that prove that l need the angle drive thingy. can l only purchase it from caterham

[Chelspeed]

Caterham don't make them, I think they're originally VDO parts.

 

But Caterham do get them modified to suit the 5 speed box by brazing on the washer that the circlip fits against. So yes I think this means you can only get them from Caterham.

 

If the angle drive is off the car and in your hand then surely you can stick a screwdriver in the square hole on the gearbox end and turn it and see the square hole in the cable end turning. If it doesn't then it's definetely that which is broke.

[Pat the Plumber]

have had it out in my hand and tried the small srewdriver and both ends twisted when either end was moved.

next bit of advice is of any help

[John Vine]

Just a (long-shot) thought....

 

If all the individual components appear to work (gearbox drive, quill, angle drive, cable and speedo), could it be that you have somehow dislodged the cable at the speedo end at some point? It's quite possible to assemble the whole shebang yet not have the square cable end correctly inserted in the back of the speedo.

 

And one other (even longer-shot) thought....

 

The gearbox drive is held in place by a metal cap (on the opposite side of the gearbox). Is this still firmly pressed in?

 

JV

[Pat the Plumber]

have tried all the easy options, have even bought the angle drive after speaking to caterham , guess what it still doesn't work.

any offers for some wizard to come round and see if l'm a complete plonker and may be missing something quite simple, especially as l've spent money on a part that is not required 😳