1988 3.0 4runner: Why would the gear on my distributor spin off the shaft? Has this happened to anyone else?

My distributor is a remanufactured NRD from NAPA and has been in use for 4 years/35,000 miles or so.

 

Not sure because I don`t have a 3.0 but all the 22 rec engines have a roll pin in the distributor .

From time to time these do break or come out for whatever reason the gear falls off or just spins on the shaft depending on the set up.

The vehicle stops really sucks along the road in a rain storm long before cell phones.

 

I rebuild my distributor (22R) a few weeks ago. I had to use a gear puller to remove my pinion, it was on TIGHT. There was no roll pin on this unit. You may have gotten a hairline fracture that loosened its friction fit to the shaft?

 

Thanks for the info - I bought a new distributor ($284 !) and it's running now. I guess it just failed - it's a press fit with no pin. Good news is my 3.0 rebuild is complete and I'm finally back on the road after 6 weeks!
Special thanks to Johnson Quality Machine in Grants Pass, Oregon - excellent work at a good price.