Yellow metal damage

[Guest sherlok]

Well just when I thought I knew what's going on, another potential gremlin rears its ugly head.

Reading the past posts, I note that there is some real concern about modern oils possibly attacking bronze transmission bushings in early Buick gear boxes. I own a '47 Road Master and since I understand the three speed gear box design went virtually unchanged for years, do I run the risk too of damaging my bearings with today's oils? I'm quite sure the previous owners of the car never thought to use lubricants from Australia.

Appreciate the advice.

Moving from Model A's to Buicks.

Thanks,

Sherlok, Chattanooga

[Guest DaveCorbin]

Dear Sherlok:

Today's oils include additives that improve lubricating qualities, so the new stuff would generally be better. Two things are, however, very important. Use the right grade of oil, something that's specifically for a heavy duty manual transmission like a Corvette 4 speed or a heavy pickup truck manual transmission. Second, do not use a synthetic type oil. The possibility here is that the residual old oil would react with the synthetics to form a soap-like compound, which solidifies and doesn't lubricate the gears and shafts.

Regards, Dave Corbin

[Guffin]

It is true that modern oils are superior to the old but it is also true that many Modern HP oils are harmful to yellow metals. The differentials of Buick up to at least 1953 used some yellow metal spacers. I don't know about the gearbox but to be safe use the same oil as in the differential. A very good modern oil is Meropa 220 from Texaco. It can be used for all kinds of gears and is not harmful to yellow metals. This is an industrial oil so it may be difficult to find in small quantities.

Jan

[Guest sherlok]

Well that makes sense. I'll try to locate some Meropa 220.

Thanks for your responses.

Regards,

Sherlok