I am about to start my 3.8ltr. 1963 MK2 after a long term rebuild.
I am now putting in fluids and wonder what is the best choice for a
4-speed manual transmision w/ overdrive. The service manual seems
to indicate 80/90 hypoid gear oil would be right. Is it? Any advice
would be appreciated.
In reply to a message from bollixx sent Sat 30 Jul 2011:
Mark,
A 63 MK2 came with a Moss gearbox, and the correct fluid is 30
wt non detergent motor oil, not 80/90 EP. That is the correct
fluid for the later synchro box. Valvoline stills makes a 30
wt non detergent motor oil. The best fluid I have found for
the Moss box is Redline MT-90.
Paul–
The original message included these comments:
Greeting,
I am about to start my 3.8ltr. 1963 MK2 after a long term rebuild.
I am now putting in fluids and wonder what is the best choice for a
4-speed manual transmision w/ overdrive. The service manual seems
to indicate 80/90 hypoid gear oil would be right. Is it? Any advice
would be appreciated.
Thanks,
Mark
In reply to a message from bollixx sent Sat 30 Jul 2011:
I used Redline’s MTL gear oil (30w equivalent) in my
four-synchro overdrive ('66 Mark 2). The MT-90 (40w
equivalent) I first used was a bit hard shifting into O/D,
but the 30 wt is quite nice. That viscosity difference has a
huge influence on the hydraulics in the overdrive.
MTL is the 30w equivalent
MT-90 is 40w equivalent
I use MT-90 in my four-synchro E-type because it has no O/D
and the slightly heavier oil seems to keep the gearbox quieter.
Synthetic has always made my Jaguar manuals shift better
than non-synthetic.
If you search ‘‘Quantum Mechanics Overdrive’’ you will find
information gathered by this east coast
transmission/overdrive shop. He used tools, pressure gauges,
etc.
I’ve been running the MTL for about 15,000 miles. It does
tend to seep out in places, but I don’t have a 30w
non-detergent baseline on this car for its comparative
leakiness.
The gearbox in my car is all original with about 65,000
miles on it, down to the o/d clutch and everything. I
resealed it when I did the engine.
Mark–
The original message included these comments:
I am now putting in fluids and wonder what is the best choice for a
4-speed manual transmision w/ overdrive. The service manual seems
In reply to a message from PS sent Sun 31 Jul 2011:
Hi Paul,
Is Redline MT-90 the best way to go for a 1963 Moss box? Or should
I use sae 30 non detergent?
Thanks,
Mark–
The original message included these comments:
A 63 MK2 came with a Moss gearbox, and the correct fluid is 30
wt non detergent motor oil, not 80/90 EP. That is the correct
the Moss box is Redline MT-90.
In reply to a message from bollixx sent Sun 31 Jul 2011:
Mark,
It is really a personal preference, many of us on this list
and the E Type list that have used Redline in Moss boxes feel
it improves the shifting. It is more expensive, but the
quantity is small and you do not have to change it often. When
I spoke directly to Redline, they recommended MT-90 for MOD
boxes because it is better at holding pressure. I suppose it
depends a lot on the condition of the gearbox, it can’t work
miracles. Do you know what is in the box now ?
In reply to a message from bollixx sent Sat 30 Jul 2011:
Thanks Paul and Mark,
I am getting a much clearer picture now of what the best options
are. I checked my chassis number and Paul is correct about the
gearbox oil requirement. 80/90 is for the later one.
There is no fluid in the gearbox now. I pulled the engine and
gearbox together and had the engine rebuilt in Seattle. I believe
the mechanic replaced the rear transmission seal and gaskets,
looked it over for smooth functioning, and then bolted it back onto
the engine for re-installation. I have been told that Redline does
tend to be leaky, but if the rear seal was replaced with new, that
might not be a big issue. Are there other seal points that could be
a problem?
In reply to a message from bollixx sent Sun 31 Jul 2011:
Mine seeps (no drips to floor) out of the joint between the
main housing and the OD housing, with some of it perhaps
coming out the studs that hold those pieces together. I
didn’t break this joint to reseal. I put copper washers on
those studs and it appeared to slow it down, but the box
still seeps some. Not enough to need to add between changes.
I would guess that if I pulled the box and resealed it using
modern sealants at all the joints it wouldn’t behave this
way, but I won’t know that for sure until I try.
Anywhere there is a copper sealing washer, I’d anneal that
washer. As I recall, there is a large one on the big nut
that holds the filter on my late, ‘‘compact’’ OD.
Mark–
The original message included these comments:
the engine for re-installation. I have been told that Redline does
tend to be leaky, but if the rear seal was replaced with new, that
might not be a big issue. Are there other seal points that could be
a problem?
In reply to a message from Whit Ranch sent Sun 31 Jul 2011:
If you take a look at the flange that connects the OD to the
adapter plate at the rear of the full synchro gearbox you
will see that the mating surface at the bottom is very thin.
This lack of sealing surface at the one area where there is
always oil sitting contributes to the leakage. My 1965 MOD
compact overdrive gearbox does the same. Your right perhaps
some of the latest high tech sealants would solve the
problem but it is not bad enough to remove the OD at this point.–
The original message included these comments:
Mine seeps (no drips to floor) out of the joint between the
main housing and the OD housing, with some of it perhaps
coming out the studs that hold those pieces together. I