[lro] ATF (was Oil or Grease or...)

From: C. Marin Faure (cmfaure@earthlink.net)
Date: Wed Jan 08 2003 - 23:57:21 EST


From: "Todd Schlemmer" <nullman@centurytel.net>
Subject: [lro] Oil or Grease or...

>....ATF was the superior fluid for use in Land/Range
Rover swivels. Posed: How does ATF differ from regular ol' gear oil? Are
there applications where they are equivalent? Is this guy so high on crack
he can't tell the difference?

ATF and 90wt (or 85/95 or whatever you use) hypoid gear oil are two
different animals. For one thing, ATF has much less viscosity than gear
oil. Our '91 Range Rover uses ATF in the transfer case, but the
chain-drive case is designed to use it. The differentials and swivel
housings on the same vehicle all require standard gear oil.

I'm not sure what advantages would be realized by putting ATF in swivel
housings. I doubt the standard swivel ball and hub seals would do a very
good job of keeping the ATF confined to the inside of the swivel housing
and hubs. They do an iffy enough job containing 90 wt. Plus I'm not sure
if ATF would provide the correct kind of lubrication to the wheel bearings,
which as you know are lubricated from the swivel ball lubricant up front
and the differential lubricant in the rear.

I have never been a proponent of using lubricants other than what the
manufacturer recomends, be it in engines, transmissions, differentials, or
steering boxes. The Series Land Rover isn't so old that its designers used
tallow and lard as lubricants. The basic lubricants that were in use after
WWII are pretty much what's still used today. Obvious exceptions are the
synthetic oils, and there have been additives developed for dinosaur oil to
help cope with things like higher temperatures. I have added ATF to engine
oil to free up a sticking lifter.... this works because of the very high
detergent content of ATF. But I was cautioned not to add any more than a
quart of ATF to the engine. Any more and the overall viscosity of the
engine oil would be lowered too much for adequate lubrication.

But I can't see ATF being used as a substitute for gear oil in any Series
drive train components. If your vehicle has oil leaks or seeps now, ATF
will likely run out almost as fast as you can pour it in. It may be that
the Saab transmissions and overdrives Todd's acquaintance works on are like
the transfer case in the Range Rover- they can operate with ATF as a
lubricant. I would guess that their seals are better and the tolerances
tighter than what you find in Series components.

Now here's a question.... I recall, but I may be dead wrong, that the
Range Rover's transfer case uses regular 90wt lube oil when bolted to the
back of a manual transmission, but uses ATF when mated to the ZF automatic
transmission. If this is the case, and it may not be, this would imply the
only reason for using ATF in the case with an automatic is to prevent 90wt
lube oil from contaminating the ATF in the transmission if, or knowing Land
Rovers, when the seal(s) between the two start letting lubricants move from
one box to the other. I don't know much about automatics, but I assume
contaminating the ATF in them with a heavier oil would be a Bad Thing.

If my recollection is correct, it would imply that the Range Rover's
transfer case is perfectly happy being lubricated with either type of
lubricant. If this is the case, I'm sure it's by design, and not by some
shade-tree mechanic's experiment. So my recommendation would be to stick
to the manufacturer's recommendation. This is just a wild assumption on my
part, but since the British came up with the fastest steam locomotive, the
fastest floatplane, WWII's best fighter engine, and the all-enduring Series
Land Rover, it's my guess they've had a pretty good idea how to keep moving
parts lubricated for quite awhile now....

________________________
C. Marin Faure
  (original owner)
  1973 Land Rover Series III-88
  1991 Range Rover Vogue SE
   Seattle, WA
   marin.faure@boeing.com
   faurecm@earthlink.net
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