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Smiths Speedo

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TR674

TR674

Jedi Warrior
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Hello all
this has probably been posted many times before, but can anyone shed some light on my speedo guage? Both my tacho and speedo indicators 'jump' around quite a lot. The tacho cable recently broke and the replacement cable stopped the jumping indicator. I greased the speedo cable and the jumping has reduced, but not by much. Is there something worn within the guage? Can they be serviced, or should I just live with it?
Regards
Craig
 
A good cause is a break in the speedo as well.There has been discussions and fixes were called out. I hope I spoke the correct Fix.
 
If greasing the cable reduced the jumping of the speedo then I would suspect that a new cable will be even more helpful. The cable can bind apart from a lack of lube (kink in the cable, damage to the housing, etc).

The jumping can also be a result of someone attempting to lube the speedo. Any more than a very very small amount of very light lube applied to a couple of specific spots can eventually find it's way to the drag cup and cause erratic action between the spinning magnet and the cup.
 
[ QUOTE ]
A good cause is a break in the speedo as well.There has been discussions and fixes were called out. I hope I spoke the correct Fix.

[/ QUOTE ]

DNK -- You're a 'Jedi Warrior' but that sounded more like Yoda to me /ubbthreads/images/graemlins/tongue.gif??
 
Thanks Geo.
I did notice a slight resistence when pushing the inner cable back in. The last 4 inches felt tight, at the diff end, i assumed the new grease would fix this. The speedo cable looks new though. I'll replace it before I pull the guage appart.
Regards
Craig
 
Craig- If my fuzzy memory serves me correctly, the binding usually is at the Trans end. By the way don't touch the diff,it's along way from the problem.

I know that was a brain typo, common here too!! /ubbthreads/images/graemlins/cool.gif /ubbthreads/images/graemlins/laugh.gif
 
DNK
yes, it's late Friday afternoon and almost beer'o'clock.
I'll be thinking alot clearer in a few hours time....
Regards
Craig
 
I took my Smiths Speedo into a local shop because it was jumping all around, too. It wasn't the cable, and new one I put in made no difference. There was no issue with the connection at the transmission.

I was told the problem was strictly internal to the speedometer. I was also told to be careful with cable grease. They said you have to keep the grease away from the unit itself.

Anyway, the point is that there wasn't any way I could've fixed it myself. Good luck.

P.S. They fixed it for $50.
 
[ QUOTE ]

I took my Smiths Speedo into a local shop because it was jumping all around, too. It wasn't the cable, and new one I put in made no difference. There was no issue with the connection at the transmission.

I was told the problem was strictly internal to the speedometer. I was also told to be careful with cable grease. They said you have to keep the grease away from the unit itself.

Anyway, the point is that there wasn't any way I could've fixed it myself. Good luck.

P.S. They fixed it for $50.

[/ QUOTE ]

Same here. My speedometer jumped around to the point that it was almost useless. Tried changing cables, cable sheath, etc. Finally sent it to Nisonger when I had to have it calibrated because of addition of overdrive and tire size change. It is now working flawlessly, and looks brand new. This would be the ultimate fix. Lots of plastic parts in the instruments, they don't last forever.
 
I had mine repaired for the same symptoms in 2004. It lasted about 500 miles. Seems now it is toasted. The speedo cable apparently had been occilating while spinning and had worn out the brass worm gear inside the speedo. Being taken apart back at the repair shop, it was full of brass shavings. I was NOT going to put more $$ into it. Period.


For all those interested in keeping things stock...stop reading from this point on... /ubbthreads/images/graemlins/grin.gif Out side of the gearing I figure speedometers work pretty much the same.
I've decided to replace the internals and use the TR faceplate for whatever might work. Well,,it might be hard to believe, but a Honda CB750 speedo is the likely donor. The odometer openings line up almost perfectly - and it has the trip odometer. Faceplate screw holes the same. The back Smiths housing needs to be cut a bit. The 700r4 transmission has several gearing options to match the speedo internals.

Actually, nothing too scary since I am using an electronic tachometer for the V8 - using the stock TR6 faceplate. The aftermarket versions out there were too different for my taste (and budget).

...another engineering project soon to be launched.... /ubbthreads/images/graemlins/laugh.gif

I may need to christen this thing a "Franken-6" when it's all said and done
/ubbthreads/images/graemlins/tongue.gif
jeff
 
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