Automatic Transmission Routine Service
One of THE most common questions is "What kind of automatic transmission
fluid do I use ?" so let's start there and get it over with ! That's
probably why you turned to this page anyway.
If you have an XJ6 your owner's manual and the shop manual specify "Type
G" trans fluid. That's where the problem begins...."Type G" is a
European designation and may be obsolete by now even in Europe.
The correct fluid to use is "Type F" or "Type FA". These are readily
available. If you prefer a slightly softer shift you may use "Dexron"
transmission fluid with no harmful effects; some Jag owners prefer
this. Incidentally, the Borg-Warner transmissions used in the 6 cylinder
cars (and older V12's) is nothing exotic, it's cousins dating back to
1950's Fords and Ramblers. It is not a particularly smooth or refined
transmission but is robust and reliable.
All Series III 12-cylinder cars (and later Series II V12's) use the
General Motors Turbo-Hydramatic 400 transmission. The correct fluid for
these is "Dexron", period. The latest formulation of this ATF is "Dexron
III" and is what you should look for. This transmission, by the way, was
first used by GM in 1964 and became a industry benchmark by virtue of
it's ruggedness and smooth shifting.
OK, on to routine service....
Firstly, check the fluid level on a regular basis and top-off as needed.
If you're a quart low your transmission will probably tell you about it
by giving sluggish shifts and delayed initial engagement.
The major consideration in transmission maintenance is changing the
fluid. At minimum the fluid should be changed every 30,000 miles but
many Jaguar owners prefer to cut that interval in half.
There are two schools of thought on changing your transmission fluid...
The standard, conventional method of "transmission service" is to remove
the oil pan, clean it, replace the transmission filter and pan gasket,
button it all up and top off the fluid. This is fine except that
dropping the pan only removes about 1/3 of the total fluid, the balance
of old fluid remaining inside the transmission.
The newer...and fast becoming popular....method is a transmission
"flush". This method uses a pump to pull out all of the old fluid and
replace it with new fluid. No old fluid is left inside the transmission.
Some clever Jag lovers have devised their own method of doing this at
home but, really, it's easier just to have it professionally done.
One common question about the new method is "what about the filter ?".
True, the filter would not normally be changed when a flush is done but
that's OK. The flushing cleans the filter and, truthfully, if your trans
filter ever actually clogs up then your transmission is beyond the point
where new fluid will help. As an alternative, do both types of service
to begin with and then just use the flush method on future changes.
You'll want regularly inspect a few things on your transmission. You'll
probably find leaks. Transmission leaks can be a real nuisance. Some are
easy to fix, others difficult. You'll have to balance expense vs.
benefit. Check the shift cable for binding or deterioration. Check then
pan for dents or other impact damage. Look at the cooler lines....check
for loose fittings and clamps and deteriorating rubber hose sections.
If trans fluid hoses are due for replacement, you must use hydraulic
hose, not fuel hose !
If your shift cable is binding and/or needs frequent replacement you'll
want to check that all of your electric grounds are in good shape. If
they are not, then your shift cable becomes the ground and goes to heck
in a handbasket ...in a hurry !
The Borg-Warner transmission does have a band adjustment but that job is
beyond the scope of this article.
Clunking with the BW trans can often be eliminated by adjusting the
downshift cable. No difficult, per se, but a delicate hand is required.
See the archives.