[propuckstopper]

Originally Posted by propuckstopper

That is what I thought, and every old "NOS" GM pilot bushing I have ever seen "appears" to be genuine Oilite Bronze. I say appears because I have never actually had one in my hand.

Give me a few minutes, and I will be back. I am going to take a picture of the junk steel bushing I took out of my car side by side with a true Oilite bronze bushing (my spare).

I think you will be able to see stark colour differences...but you be the judge in a moment or so.

OK. I have snapped a total of five pictures, and would like to take a moment to explain each.

Photo one shows a picture of a genuine Muncie transmission input shaft. A transmission guy gave this to me to use to install the new pilot bushing as well as to use this as a clutch disc installation tool. If this input shaft looks a little weird to you, it is. A machinist friend of mine cut the gear off at the end of the shaft for me. He made it easier for me to use as the aforementioned clutch disc installation tool. This genuine Muncie input shaft fit much better than the cheap plastic installation tool supplied with the clutch kit, enabling the transmission to slide in much smoother. Note the diameter of the shaft. The Chinese magnetic pilot bushing is on the bottom, and the new Autogear Oilite pilot bushing is on the top. The Chinese bushing had been used for about 1000 squealing miles before I took it out. It was cleaned up with brake clean before this photo.

Photo two shows the magnetic Chinese bushing taken out of the car. Note the .6035 measurement. I do not know what diameter this bushing left China with, but it is a lot bigger diameter now than the genuine Muncie input shaft would like to see. However, as PONTIAC DUDE suggests, I obviously should have lubricated this bushing. The extra big diameter was probably caused by lack of lubrication, hence the squealing.

Photo three is pretty straightforward. This picture shows a new Autogear Oilite bushing. It is virgin. Note the measurement of .591.

Photo four shows the Autogear Oilite bushing on top, and the Chinese magnetic bushing on the bottom. Again, the Chinese bushing has been well cleaned. Just showing this picture for comparative purposes, but note the Chinese effort looks far from bronze.

Photo five supports all the information from the links I supplied above in an earlier post. I put the bushings side-by-side on the counter, then "snuck-up" to them with a magnet. I don't need to tell you which one stuck and which one is laying on the counter.

At the end of the day, I fully realize that PONTIAC DUDE is correct in saying that I should have lubricated the magnetic bushing. It certainly would have eliminated the squeal and excessive wear. Yet, all my research pointed to not having to lubricate the bushing, because I believed it to be self-lubricating. It wasn't, as the calipers show. I also believe this: PONTIAC DUDE has been lubricating pilot bushings for over 40 years. Somewhere, in the span of 40 years until now, the composition (metallurgy) of these bushings has gradually changed. Forty years ago, I believe they were genuine Oilite and that fact that PONTIAC DUDE added extra lubrication really did no harm. As the metallurgy changed, PONTIAC DUDE continued his method of lubricating them and had no problems because the more modern bushing actually requires lubricant. If I am correct, PONTIAC DUDE may have spared tons of more modern pilot bushings because of his original methods, and there is certainly nothing wrong with that!

I would absolutely love to get my hands on a genuine NOS GM pilot bushing just to see what material they were made of back then. I would bet the farm that they were Oilite or a derivative of the same.