No longer available from GM. Need a source for OEM or aftermarket. Brown, 18 tooth, according to the parts manual. Original part number 12554183. Anyone have a source?

 

What specific trans are you working on? The 4L60 used in the 93 had the gear in the VSS. I thought all the 4L60E's had the reluctor gear on the output shaft.

In any case. try the jagsthatrun.com website. The 4L60/60E parts are down at the bottom of the main page.

 

It's for a friend's 94 Z28. I'm not real familiar with automatics and I haven't cracked the manual yet. Is it an easy replacement job?

 

If its a 94, it does not use a gear driven VSS. Only the 93's. On a 94, you adjust the speedo in the PCM, not by changing the driven gear.

 

I understand that, this is a case of the gear being worn out at 200K miles. Just looking for replacement parts.

 

I'll try this one more time, because apparently I'm too dense to understand what part you are looking for.

What speedo drive gear? There is no speedo drive gear in a 94 4L60E. There is a reluctor wheel on the output shaft, and the sensor is a magnetic (Hall effect) pickup. The pickup sends the voltage pulses to the PCM, which interprets the pulses based on programmed rear axle ratio and programmed tire diameter, and sends the calculated pulse signal to the speedo. Totally electronic. The reluctor wheel may look like a "gear", but it isn't. And the reluctor in the 4L60E has 40 "teeth" on it.

A 1993 4L60 would be a different story, because it does have a gear actually driving the VSS pulse generator.

 

I'd be the last one to agree that you're dense. In fact I think you just supplied a clue.

Just occurred to me that this is not the original transmission in this car, was replaced about a year ago. Possibly they installed a 93 transmission?

Unfortunately the car is not local to me or I'd check myself.

 

Well she went back and pursued the matter with the service manager. And whaddya know? They've changed their diagnosis. A reluctor wheel is on order.

Hopefully that will fix the problem but I'm taking a wait and see attitude. Based on her past with this shop (which I won't go into) I have my doubts.

Anyway, thanks for helping, Injuneer.