1940 chevy speedo

[hdbob5454]

the cable  went  in the  speedometer  and  buried  the  needle , how  can  I  get  it  back  to  zero ?  

[Andy J]

I have a '40 Chevy Master 85 but I don't know anything about the speedometer. I'll be paying close attention to this so I might learn something.

[m-mman]

Please explain further. 
1. the speedometer was working fine?

2. You removed the cable from the back, because?

3. You wanted to lube the cable?

4. You reinserted the cable into the housing (outer cable)?

5. You insured that the cable was fully seated into the outer “cable” and transmission?

6. You reconnected the cable to the speedometer?

7. The needle immediately moved to the 100+ mark when connecting the cable?

8. The needle immediately moved to below zero when connecting the cable?

9. You connected the cable to the speedometer, drove as fast as possible and the needle is stuck at 100+?

10. You reconnected the cable to the speedometer drove at a slow speed and the needle was bouncing radically eventually becoming stuck at either zero or 100+?  

Details are critical to offer troubleshooting advice. 

Edited December 27, 2023 by m-mman (see edit history)

[hdbob5454]

speedo  was  working  fine  until  cable  started  making  noise  getting  louder  until  needle  went  past  100, I  disconnected  from  Trans  and  needle  is still  out  of  sight . I haven't  disconnected  from  speedo  yet I'm  hoping  it returns  if I  do, I just  put  it  in  storage  for  winter  have  a  few  things  to  work  on  collecting  parts . thanks  for  any  help  

[m-mman]

Nope, not an easy repair.  
A speedometer works by spinning magnets around a steel drum.  The magnets are spun by the cable, the faster they spin the greater the magnetic field that moves the drum that is attached to the needle.  
 

The magnets and the drum never touch. 

The cable doesn’t make noise. BUT the bearings (aka Jewels) that position the spinning magnets does make noise. (When they are worn out.  They aren’t designed to be lubed, they last “the life of the car”). 
 

Most likely your spinning magnets touched the drum, slamming it into the stop at 100 mph. 
 

Speedometer work is similar to jewelry and watch repair.  Unless you have the tools and skill set it is best to let an expert repair it.  
 

Look up speedometer repair in your area.  Big trucks need this service.  
 

Otherwise I recommend Bobs speedometer repair.  He does old cars.  He is not cheap, but his quality is outstanding.