>I don't understand where the use of motor oils in transmissions is
>coming from. I have heard of people adding sawdust to their
>transmissions to quiet them down to but that doesn't mean I am going to
>do it. Using motor oil may be some mechanic's short term solution to a
>bad rebuild, I don't know.
*****************************************
I believe that the motor oil usage, related to British cars in general,
stems from those who have or have had MG's. Certain models of MG's (* see
below) use regular motor oil in the transmission, which is (also I believe)
specified in the service manual, for use in those trannys. (those who own
MG's can validate that for me, and we KNOW who you are. . .:-})
However there may be specific differences which allow it's use in
those boxes. I would gather though, that the rear axle still specifies
that hypoid gear oil be used (and for good reason). The load's imposed in
that assy are far greater and the shearing action of the hypoid gear is
much more severe. I'd bet that using motor oil in the rear end would lead
to a very early demise of the ring and pinion. It is interesting to note
that while hypoid gears have a much more aggressive "sliding action" over a
broader area of gear teeth by their design, helical cut gears still do the
same thing, but to a much lesser degree. It would also be interesting to
see if the trend of using motor carries over to the later Midget which uses
the Spitfire/Marina single rail gearbox. I'll bet that it specifies gear
oil for those :-)
As for the sawdust, that's an old sellers/bad mechanics trick to quiet a
noisy transmission to sell, or get rid of the car, without fixing the problem-
*and quite possibly other models. My Borg/Warner T5 five speed manual,
specifies ONLY Dextron II/III automatic transmission fluid [fluif] be used
Barry Schwartz (San Diego) bschwart@pacbell.net
72 PI, V6 Spitfire (daily driver)
70 GT6+ (when I don't drive the Spit)
70 Spitfire (long term project)
|