Speedo runs backward???

[repo68]

Hi all,

A newbie here.  I recently bought a '70 Chally, and I just finished a standard gage to Rally conversion.  I followed the instructions posted on this site and it went together quite easily.  his site Everything works except the gas gage, clock & speedometer. 

The speedo has me perplexed though.  I tried spinning it my hand, and it appears to work, but only when I spin the cable in the reverse direction.  (The needle goes the wrong way too)   I checked my old (std) speedo in the same way, and it runs exactly the opposite (correct direction).

The previous owner gave me the Rally instrument cluster with the car, so who knows what's been done to it.  I'm just wondering if anyone has seen anything like it before. Maybe it's a simple fix I could do myself?   

Thanks for any help,

Pete

[Chryco Psycho]

wierd

[73EStroker]

I know our American cousins are not allowed to import and smoke those good Cuban cigars so you might have to slow down on the wacky baccy imported from BC.

Seriously though - are you saying the speedo runs backward in the car driving down the road? If you are trying to turn the speedo with the dash or speedo out of the car then you do turn it "backwards" looking at the speedo cable entry point on the back of the guage. this equates to counterclockwise at the back and clockwise looking from the front.

[repo68]

  

No smokin, really...

Actually, I need to double-check which way I was spinning the cable for each gage.  What's strange is, the Rally needle only moves in the reverse direction, and the original only in the forward direction.  Again, I don't remember way I spun the cable.  I'll let you know...

[repo68]

Okay,  I double-checked the cable rotation.     Basically, the Rally needle will only move if I rotate the cable CW (looking at the trans connection end). But when I do this, the needle rotates in the wrong direction from zero.   If I rotate it CCW, the needle doesn't move.   

With the standard gage, the exact opposite happens.  Rotating the cable CCW causes the needle to rotate in the correct direction.  Rotating it CW, the needle doesn't move.

Makes me think the Rally speedo was possibly rebuilt and assembled incorrectly.  Has anyone taken one appart?  Is it possible to assemble the needle mechanism inverted or upsidedown?

[repo68]

Probelm solved!   

Just in case anyone ever has a similar problem...   I pulled the gage, and found that a small metal tab, which rotates with the speedo mechanism, hits a brass rod which acts as the stop for zero. 

Bascially the mechanism rotates (maybe by friction) against a small torsion spring, which is always trying to pull it back to zero.  The tab and brass rod stop it at zero, and also prevent the dial from going backward when you drive in reverse.

With mine, somehow the metal tab got past the brass rod so it could move in the reverse direction, but not forward.  I just forced it back to the other side, and now everything is back to normal.   

Sure beats sending it somewhere to be rebuilt for big $$$. 

[MEK-Dangerfield]

Glad you found the problem, because I was stumped. 


  Mike

[70RTdroptop]

Remember Stephen King's " Christine " ? That car had that weird problem, too. Course, she also liked running down people she didn't like, too.

[Bearcuda]

MMmmmmm......C_H_R_I_S_T_I_N_E