Speedo Gear drive removal 62 Vette 4 Spd

[Scotty]

Hi All,
I was wondering if someone can let me know how difficult it is to remove the plastic gear drive from my 62 Corvette with a 4 spd manual?
I have only just purchased the vehicle here in Australia and at this stage have not put a jack under it. Is it an easy removal and install or do I have to drop the box?
I note that the Speedometer is not working and thinking if I remove the cable from the box and check the cable to ensure that turns the speedo then I assume the drive is knackered?
Any assistance would be greatly appreciated......
Scotty

 

[Midnight 99]

The driven gear is easy to and replace. The drive gear on the tail shaft requires the removal and partial disassembly of the transmission (tail shaft housing). The driven gear is nylon and the drive gear is metal. Definitely check the cable first. If the cable operates the speedo, you need to remove the driven gear to see if the hole in the center is still square and the teeth have not been worn off the surface. To remove the driven gear you need to remove the hex bolt and slide the retainer plate out of the slot and then pull the housing out to replace the gear. The driven gear is usually the culprit. Before you replace it make sure that you know what your final drive gear ratio is so that you purchase the correct replacement part.

 

[Scotty]

Thanks Midnight, I assume I can do the removal under the car whilst the box is still in situ?
Cheers
Scotty

 

[Midnight 99]

Yes you can but you need to get the car up high enough to move around under there. The driven gear is located on the left side of the tailshaft housing on the Borg Warner trans. If your trans is not original and has been replaced with a Muncie, it will be on the right side of the tailshaft housing. If you have the correct trans for your car it will have a cast iron housing while the Muncie is aluminum. Please be careful and ensure that you use quality jack stands to support the car while you work.

 

[Scotty]

Thanks midnight,
Update is as follows...
Removed the speedo cable today not the nicest being on ya back most of the day found the best way was to remove the gearbox cross support that way u have easier access..
Tested cable with a drill not working pulled out plastic 21 tooth speedo drive not issues removed cable from rear of speedo checked again with drill it rotates.
Put cable back in to rear of speedo and found that it only worked if u apply pressure to the cable force towards the speedo end.... Phew working placed cable back into gearbox whilst the cars was on stands I thought I would try well you beauty she works..... Yes only for about 10 seconds.
So now I have ordered a new speedo cable hopefully this will solve the issue..
Scotty

 

[Midnight 99]

Cool. It sounds like the cable may be the culprit. Did you check the inside of the driven gear to make sure it was still square? If it is, the other issue may be the square hole in the speedo itself is rounded. Not trying to kick sand in your eyes, just making sure you find the problem so you can fix it.