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How To Replace Speedometer Gear 64-74 Pontiac GTO

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  1. step : Removing the Speedometer Gear (0:33)
    • Disconnect the shifter from the transmission
    • Disconnect the speedometer cable with pliers
    • Remove the speedometer housing with a 7/16" socket and ratchet
    • Remove the speedometer gear from the speedometer housing
  2. step : Installing the Speedometer Gear (1:53)
    • Insert the speedometer gear into the speedometer housing
    • Push the speedometer housing into place
    • Tighten the speedometer housing with a 7/16" socket and ratchet
    • Connect the shifter to the transmission
    • Road test the vehicle, checking that the speedometer reading is accurate

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Hi, I'm Mike from 1A Auto. I hope this how-to video helps you out, and next time you need parts for your vehicle, think of Thanks.

In this video we're going to show you how to change the speedometer adapter gear on this '66 GTO with a Muncie 4 speed. This procedure is the same for a whole lot of GM Cars that use the Muncie 4 speeds. The biggest trick to this is getting the right gear. We've done a whole lot of work on GTOs through the years so we've got a little stock pile of extra ones for our own cars. We'll get on with it.

Here we're starting. You see that the transmission cross member has been taken out and moved back and also that the shifter has been basically disconnected. You do not have to move the transmission cross member. I just did that to make it easier to video. You will have to disconnect your shifter. Well, technically you don't have to, but it makes it a whole lot easier to get in there and get the speedometer cable off and then the gear housing out.

Start using a pair of pliers and disconnect your speedometer cable. Right here is my speedometer housing. If you change the gears in your car you'll want to change the gear in here. Right now it has a purple one. I can see a little purple end here. All I'm going to do is take out this 7/16 bolt here. Just loosen that up and then pull this out. This car had a purple in it which makes sense because this transmission was last in a car with a 308 rear end. We're going to go to a red. The red, actually, you might be able to see, has a few more teeth. That's because this car has a 355 rear end. This gear gets driven by a gear in there, and the more teeth it has, the slower it drives it, and therefore it reads the correct speed. I put that back in, flip this back up and around, and then tighten up the bolt. Now at this point you would want to put your speedometer cable back on, reconnect your shifter, and you should be all set for a road test. Make sure that speedometer is a little bit more accurate.

We hope this video helps you out. Brought to you by, your source for quality replacement parts and the best service on the Internet. Please feel free to call us toll-free, 888-844-3393. We're the company that's here for you on the Internet and in person.

Tools needed for replacement:

    Pliers, Cutters & misc Wrenches

  • Slip-Joint Pliers

  • Ratchets & Related

  • Ratchet

  • Sockets - SAE

  • 7/16 Inch Socket

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