Ray Gibbons writes >
> Philip Ethier advised use of *non-detergent* 30W oil in Spridget
> transmissions, to save the synchros. I have an early ribcase transmission
> in my bugeye. I read all of the relevant manuals, and don't recall a word
> about non-detergent. I know I am using standard detergent motor oil; it
> may even be 10W30. I believe the manuals I read said this was OK.
OK, we have been around this block before. I was told this by Jack
Nesset, the mechanic that went through my Spridget gearbox when it stuck
in first gear. Jack has been a race car mechanic since Tipi was a pup.
He has worked on everything from TD's to CanAm cars. He told me that
Midget synchros have a coating on them which the detergents in motor oil
consider dirt, and dutifully work at removing. He told me that was
why my fourth-gear synchro was giving me trouble, and that the others were
on their way. He put in some good used ones from Mark Brandow and the car
shifted much better.
There are two possibilities about Jack:
1. He knows what he is talking about.
2. He does not know what he is talking about (I doubt this one).
There are two courses of action a Midget owner can take.
A. Use only non-detergent oil.
B. Use something else.
There are therefore four combinations possible:
1A You have saved your synchros from harm.
1B You may be screwing up your synchros.
2A You are not really helping your synchros, but you aren't hurting anything.
2B You aren't hurting anything.
So, whether Jack knows his stuff or not (I think he does, so did the guys
that paid him to maintain Lola-Chevs), you can't go wrong with the
non-detergent oil. Don't forget that the detergents in motor oil are
there largely to deal with combustion by-products that are not in your
gearbox.
Since I can't think of one good reason to use detergent oil, and there may
be a BIG reason not to...
phile@stpaul.gov
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