Does this apply to the earlier models? I've removed the 'oiler' and replaced it with a grease nipple to keep muck and dust out, but never bothered actually sticking grease in - mainly due to advice on GoMog.
The earlier oiler type kingpins had a very small hole drilled down through it and I think you would really struggle to get grease through, whenever I’ve worked on front ends because the cost of parts is so reasonable I’ve always replaced King pins and bushes every strip down because 3/4 of the cost is labour even when doing my own car.
I always used hard chrome kingpins and spiral grooved phosphor bronze bushes from Peter M at Mulfab but since Pete’s retirement would shop via Cain at Wolf Performance.
