Speedo Problem?

[veale001]

Hey guys.

Figured I ask another noobie question, since I got soo many good responses last time round.

The speedo on my 73 tr6 has gone the way of the dodo. The gauge was beat up pretty bad so i opted to grab a new(refurbished) one. I purchased a Smith Gauge #SN6317/04A from "the gauge shop" on eBay. I also got a new cable. I greased the cable and it is secured properly on both ends. Sounds like there shouldn't be a problem right? Wrong. I dont think its the gauge because the needle floated around using the old cable that was worn/stripped?

Any help would be appreciated.

Thanks
W

 

[TR3driver]

I'm not sure I understand the problem with the new speedo; but it's a very common problem apparently for the inner cable to protrude too far. The speedos are very sensitive to pressure applied to the workings by the cable being too long; as the bearing between the input shaft and the needle shaft looks more like something that belongs in a clock. You might try loosening the fitting at the speedo by a few turns and see if that has any effect on the problem.

It may be that both the old and new cables have the same problem; the excess pressure may even have been what caused your old speedo to fail.

 

[martx-5]

I'm ran into the same problem with my tach. When it came out of the car before the resto it was working perfectly, so all I did was take off the glass and clean things up. After I got everything put back together, with a NEW cable, the tach started bouncing around and making lots of noises.

I dug out the ORIGINAL cable that I had stuffed in the loft, put it in, and the tach worked like new.

Edit: Just as a point of information. I put in the Toyota trans conversion using the kit from HVDA. It came with a new speedo cable. Despite the fact that it makes quite a tight turn when it leaves the tranny, it works flawlessly. No bounce or noise whatsoever from the speedo. I guess that Dutch engineer knows where to buy stuff. (Actually, he probably has that made up for him)

 

[veale001]

I forgot to mention that the gauge floated around with the old cable.

I took the gauge out and drove around the block. The cable did not move at all? Can it be too tight at the other end?

 

[Geo Hahn]

Never heard of it being too tight there -- in fact, given that is the loose end, in cannot be too tight there -- just is what it is. Soooo...

If the cable isn't turning it is either broken or not engaged. You should be able to withdraw and reinsert the cable from the speedo end of the housing, but when reinserting you fiddle it until it seats in the square drive on the gearbox, once it seats you cannot turn it from the the speedo end.

If you drive with the cable not connected to a speedo it may pop out and thus not be engaged -- though you can press lightly on the end of it to keep it engaged and feel it turning.

Be careful if you do this -- especially if you have hairy legs. Someone out there must know what I mean. Ouch!

Guess I should ask if the cable goes directly to the gearbox or to an angle drive (i.e. do you have overdrive?).

 

[veale001]

Directly into the gearbox.

The cable didn't engage the speedo in my first or second try at installation. When people say the cable is broken, do you mean if I retract the inner wire out that the wire will actually be broken aka kinked or in two pieces? Both ends seem to be in good condition.

Speedo cables are one size fits all right?

Thanks for all the help,
W

ps: Im interested to hear the hairy legs scenario

 

[TR3driver]

When people say the cable is broken, do you mean if I retract the inner wire out that the wire will actually be broken aka kinked or in two pieces?

Well, that's what I call a broken cable.
<div class="ubbcode-block"><div class="ubbcode-header">Quote:] Speedo cables are one size fits all right?[/QUOTE]No, but the big Triumphs use a pretty common size. Some cars do have a slightly larger or smaller square on the ends though; for example my angle drive won't fit into the speedo gear on the Volvo J-type I bought for parts; but fits the original J-type just fine.<div class="ubbcode-block"><div class="ubbcode-header">Quote:]ps: Im interested to hear the hairy legs scenario [/QUOTE]What, are you a masochist? Gives me the willies just thinking about it! Basically, any spinning shaft can grab hairs and yank them out by the roots.

 

[veale001]

In regards to the size of cables. The gauge is a Smith, made for a Jaguar so I wanted to know if that was the problem.

<div class="ubbcode-block"><div class="ubbcode-header">Quote:] Basically, any spinning shaft can grab hairs and yank them out by the roots.
[/QUOTE]

How many of you have hairy thumbs?

Anyways I pushed the inner cable in with my thumb while the the speedo was out and it was engaged and spinning for a moment and then stopped again. How do I keep the inner cable forced in the gearbox?

 

[TR3driver]

Anyways I pushed the inner cable in with my thumb while the the speedo was out and it was engaged and spinning for a moment and then stopped again. How do I keep the inner cable forced in the gearbox?

IMO that means there is something else wrong. Normally there is a collar at the speedo end that keeps the inner cable from moving too far one direction or the other; but it's not supposed to keep constant pressure in either direction. The square end of the inner cable should be free to move in the square socket at the gearbox by at least 1/4" or so, without losing drive. (It will move somewhat, as the engine/gearbox move on their mounts, because the outer cable changes length when it flexes.)

Sounds to me like your inner cable is too short, or broken, or possibly just doesn't fit into the shaft in the gearbox. Time to pull the gearbox end off and see what's going on.

 

[veale001]

good answer.