Looking at the 1979-1980 catalog and the 1981-1982 catalog it looks like the oiler went away around 1980-1981.
The 1979-1980 catalog has for the 1/4" 3/8" 1/2" part numbers 43175 43785 43975. There is a picture of one ratchet that shows the oiler.
The 1981-1982 catalog has for the 1/4" 3/8" 1/2" part numbers 43185 43784 43985.
But my 1/4" oiler has the 43185 part number from the 1981-1982 catalog, and my 1/4" non oiler 43186 is not listed in either catalog. Next time at the flea market if I see a ratchet that had the hole plugged I will pay attention to the part number.
TP,
Dave (Mr Craftsman Ratchet) and I recently traded emails regarding the 1/4" drive teardrop ratchets. Here's a summary of what he told me:
Model 43175 (this was the 2 patent ratchet with no model number stamped on it) was available from 1969-1979. This V-series ratchet had an oiler, QR, and a thru-post in the drive bit.
Model 43185 (MN stamped on the handle) was available from 1980-1989. This V-series ratchet had an oiler and QR, but no thru-post in the drive bit.
Model 43186 (MN stamped on handle) was available from 1990-1993. This V?-series (maybe V^) QR ratchet had no oiler or thru-post in the drive bit. And, the ratchet gear was upgaded from 24 teeth to 30 teeth. This model would have been the first of the Danaher period (the previous two models were from the Easco period).
So, according to Dave, and the 1/4" drive ratchet evolution history, the oiler disappeared in 1990.
That's my story and I'm sticking to it (at least until I have a new improved story). BTW-You and I may be the only two people here who fully appreciate the difficulty of re-documenting Craftsman tool history. So many twists and turns, and inconsistancies between sources!