Speedo drive is seized on the wheel bolt.

The drive wheel has a locking tab washer under the bolt which holds the wheel assembly on the end of the drive shaft. Step one is to bend the tab (or tabs) away from the side of the bolt. Put a socket on the bolt to remove it. Make note of the washer and lock tab orientation because there is another tab on the inside which locks into the motor shaft keyway. Spray lube into the shaft and keyway to free up the wheel and remove. A wheel puller is sometimes helpful here. When replacing the parts use Loctite on the bolt and tighten. The final step is to bend a lock tab up against the bolt head to keep it from backing out. The hard part of this whole process is removing the wheel assembly from the motor shaft. It may have seized on to the shaft. Place anti-seize or grease on the shaft after cleaning and before reassembly.
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Well......it depends on the application....997 twin turbo 911....or a chevette.....

when you spin the front wheel with the cable removed, does the spindle turn in the speedo drive?
If not:
1) Check that drive is fitted correctly, often there is a washer or spacer that if omitted can stop the drive from working
2) try another drive unit in the wheel.
I think that option 1 is most likely

Is the speedo electronic or cable operated? If cable operated there are a number of things to check. Firstly remove speedo cable from back off guage. Remove speedo cable from speedo drive generally front wheel. Check that the inner is still one piece, by spinning. If that is good you need to check if your speedo drive is functional. Screw cable back to drive, lift front wheel and check if cable inner is turning, if it is you may need a new speedo. (spring worn like my old Triumph.

you need to raise front wheel from ground with hoist or stand
remove brake calliper bolts and then twist callipers on disc to push pads back so that you can remove callipers.
loosen pinch bolts on one fork leg then undo axle nut ( large allan bolt) loosen other pinch bolts on other leg and remove axle and spacers/speedo drive and the wheel. take note where spacers go and also make sure to line up speedo drive tangs correctly when refitting wheel in reverse order to taking apart.

FIRST SECURE THE BIKE ON A SUITABLE REAR STAND, WITH THE FRONT WHEEL STIL ON THE GROUND, UNDO THE 2X 6mm ALUN KEY PINCH BOLTS ON THE R,HAND FORK, NOW INSERT A SUITIBLE KEY INTO THE SPINDLE AND CRACK OF THE SPINDLE IN AN ANTICLOCKWISE ROTATION, WITH THE SPINDLE NOW LOOSE, SUPPORT THE FRONT OF THE MACHINE AND RAISE THE FRONT WHEEL OF THE GROUND, DONOT UNDO THE ALUN KEY BOLTS ON THE L,HAND FORK AND CONTINUE TO UNDO THE SPINDLE FROM THE R,HAND SIDE, REMOVE 2X 12mm BOLTS FROM EACH OF BRAKE CALIPERS, TWIST THE CALIPERS SLIGHTLY TO PUSH HOME THE PISTONS TO EASE REMOVAL, YOU SHOULD NOW BE ABLE TO REMOVE THE CALIPERS FROM THE WHEEL BY PULLING THEM BACKWARDS AWAY FROM THE DISC, REMOVE SPEEDOMITER CABLE, THIS WILL EASE REPLACMENT, AS THE SPEEDO DRIVE CAN BE A BIT TRICKY TO LOCATE ON TIMES, THE SPEEDOMITER DRIVELOCATES IN THE LH FORK WITH A SMALL LUG, THE REASON YOU DONT UNDO THE LH SIDE IS TIGHTENING THE SPINDLE FROM THE LEFT PUTS FRICTION ON THE SPEEDO DRIVE AND BREAKS OF THE LUG, WHEN REPLACING THE WHEEL LOCATE THE SPEEDOMITER DRIVE IN THE WHEEL FIRST AND ENSURE CORRECT LOCATION, WHEN BACK ON THE BIKE TIGHTEN THE WHEEL FROM THE RH SIDE IF THE DRIVE IS LOCATED CORECTLY, WITH NO CALIPERS FITTED THE WHEEL WILL SPIN FREE, IF IT IS NOT CORRECT WHEN YOU TIGHTEN THE WHEEL IT WILL HAVE A SLIGHT BIND AND SHOULD BE REMOVED AND REFITTED CORECTLY

First off you should remove the front caliper, there are two bolts holding that on the lower fork leg, once that is removed that you can loosen the axle and slide the axle out.

Pay close attention to the spacers and the speedo drive when you remove the axle so that you install everything proper when you put it back together.

Also you'll notice that the speedo drive only goes in one way, there are two tangs that need to be lined up on the receiver part of the hub, those have to slip into each other, if not you will damage your speedo drive.

Also before you start make sure you have something to hold the bike up since you will be pulling the front wheel out of it.

Torque the axle nut to 65 ft-lb
Torque the caliper bolts to 24 ft-lb

First, remove the lower end of the speedo cable from the speedo gear box on the front axle. Then, lift the front wheel off the ground and remove the wheel. To remove the speedo-drive gear box, unscrew the axle nut that holds it in place. With the speedo-drive removed, inspect the two flanges that fit into the slots on the wheel hub, making sure they haven't gotten bent - or sheared off. When you turn flange on the speedo-drive, it should turn freely and you should be able to see the speedo cable drive-blade spinning. If not, then you will need to replace the whole unit because the worm gear inside has become excessively worn.

This depends on whether it is an electronic speedo or a mechanical speedo.
The electric speedo has a sensor near the rear of the engine. Sometimes a very small piece of metal will get stuck on the end of the sensor and the speedo will stop working. Remove the bolt holding the sensor into the engine case and carefully pull the sensor out. Wipe it off and reinstall it. If the speedo still does not work, it's probably something in the speedo itself.

On a mechanical speedo, a cable from the front wheel drives the speedo. The cable or the speedo drive unit may be bad. To check the cable and drive, lift the bike off the ground, disconnect the cable from the rear of the speedo. Turn the front wheel and see if the cable is turning. If it is, it's probably alright. I'd still pull the cable out of it's housing and lubricate it with some grease. If the cable is turning, the cable and drive unit is alright. The speedo may be broken.

Hi ...... You need to support the bike level (front paddock stand) and undo one side pinch bolt then using the hex adapter for that side unscrew anticlockwise ..................... I cant remember whether it's a 15mm or 17mm. The front spindle is threaded both sides. Support wheel & pull spindle out. Assembly is reverse but you have to make sure speedo drive is engaged correctly prior to tightening up.