Speed Servo gear

[Paddywhack]

The fun just keeps piling on this weekend. Figured I could still change the speed sensor in the 4+3 since the speedometer hasnt worked since I owned the vehicle. Got the old sensor out and fournd out why it didnt work...there is no gear on the shaft! Is this gear available anywhere?
Thanks

 

[vetteoz]

Better auto trans shop or a GM dealer
Same as T700 /4L60 auto gear

If you have stock 3.07 rear then you need the green 42 tooth driven gear.
GM Part # was 25513049.
Make sure the red gear that drives it is on the output shaft as well

 

[Paddywhack]

I THINK its the stock rear end...but nothing surprises me lately...how can I be sure?

 

[redvett]

You should also have a SES light since there is no speed input to the ECM. This will cause poor performance and drivability.

 

[toptechx6]

I THINK its the stock rear end...but nothing surprises me lately...how can I be sure?

Positive identification would require removing the batwing to see the markings on the ring gear, however, if you suspect the car has been modified the easiest way to determine the rear axle ratio is to jack up the car and safely support so both rear wheels are off the ground, mark a line on the front yoke and differential pumpkin with chalk, place the transmission in neutral then rotate the rear wheels until the driveshaft makes one complete revolution while counting the number of wheel or halfshaft revolutions needed to do so.
A close approximation corresponding to the available ratios would be 2 1/2 turns = 2.59, 3 turns = 3.07, 3 1/2 = 3.45 etc.