Moss Rear Seal - My Story
Posted: Wed May 10, 2000 2:42 am
After reading the latest rear seal thread I have copied my e mail
correspondence with Al Moss. this took place last week. Hopefully
it will be useful.
I wrote:-
".............About 1 year ago I fitted one of your seal kits to my TC.
This was the new version which I got from Moss California. I also
fitted the Speedi-sleeve. I followed your instructions with great care
and made sure that there was concentricity and that the seal was in
proper contact with the Speedi-sleeve.
For the first couple of hundred miles there was a normal XPAG
drip. I then went on a 250 mile rally and the drip disappeared
completely. After this it returned and has got steadily worse. Now,
maybe 1500 miles later it is really bad and I am getting comments
every time I stop the car!
There has been a lot of discussion on the internet about this kit
and there seems to be some consensus that the surface speed is
to great because of the large diameter. Some people suggest that
a "Viton" seal be used. Others say this won't help.
I can't remember what type of seal was supplied with the kit but
perhaps you can offer me some advice before I strip the motor for
the third time.
My options are :
1. Replace the original seal and pray - not a good one?
2. If the original seal was not viton, install viton seal if
available.
3. Put it back the way it was when it left the factory!
If you recommend 2. can you tell me the part number and supplier
of this item?
Can you help?..................."
Al Moss replied the next day as follows:-
"...............Sorry to hear you are experiencing trouble with the Seal
Kit. If you will e mail me your address I will mail you an updated
instruction sheet (revised 9/99). Yes, I am well aware that we are
running the seal at a higher than recommended surace speed, as
well as a higher temperature. However, this has not been a
problem. I know of quite a few cars, including my own TC, which
have completely successful installations and have been or are
being raced at very high RPMs and very high temperatures. There
IS NO Viton seal available in the required size. CR (Chicago
Rawhide) lists such a seal and will only make a huge run to special
order. They do list an intermediate seal rated at higher RPM &
temp and it WILL NOT WORK!!! It is designed for something like
mineral oil and fails immediately in a car engine. I am sure if you
read very carefully and follow each and every instruction, you will
have a successful installation....................."
Like Neil's friend, I know that it was properly installed and this is
borne out by the fact that it worked well for a while. I am sure that
the high temperature wrecked the seal as has been suggested.
Now it has sort of settled in at the embarrassment level.
On my new cream TC I mave just completed the motor and I have
used the Chevy seal as per this list.
The problem is what to do with my black car without having to do a
full strip down to put in a Chev seal.
This week a talked to Chris Champion, a local TD owner who made
his own Moss type modification. He found out that Toyata use a
similar system and it works fine. He has used the Toyota seal in
his car which is driven lots and hard without any problems. Their
seal has an ID the same as the XPAG flywheel flange plus speedi-
sleeve. The OD is 115 mm against the Moss seal's 120 mm. I don't
know what material has been used but it feels much softer than the
Moss seal and it has a sort of angled rough surface on the inside
which probably acts as an extra oil thrower. The seal itself is a bit
wider but Chris machined it to fit without difficulty.
My latest plan for the black car is to machine a sleeve and then to
put a thinned down Toyota seal (HTC95) into the Moss housing and
then hope for the best.
In the meantime, with club events of considerable distance planned
for the next 2 weekends, I will just hold thumbs. The good news is
that chassis and underbody corrosion aft of the bell housing will be
substantially reduced.
correspondence with Al Moss. this took place last week. Hopefully
it will be useful.
I wrote:-
".............About 1 year ago I fitted one of your seal kits to my TC.
This was the new version which I got from Moss California. I also
fitted the Speedi-sleeve. I followed your instructions with great care
and made sure that there was concentricity and that the seal was in
proper contact with the Speedi-sleeve.
For the first couple of hundred miles there was a normal XPAG
drip. I then went on a 250 mile rally and the drip disappeared
completely. After this it returned and has got steadily worse. Now,
maybe 1500 miles later it is really bad and I am getting comments
every time I stop the car!
There has been a lot of discussion on the internet about this kit
and there seems to be some consensus that the surface speed is
to great because of the large diameter. Some people suggest that
a "Viton" seal be used. Others say this won't help.
I can't remember what type of seal was supplied with the kit but
perhaps you can offer me some advice before I strip the motor for
the third time.
My options are :
1. Replace the original seal and pray - not a good one?
2. If the original seal was not viton, install viton seal if
available.
3. Put it back the way it was when it left the factory!
If you recommend 2. can you tell me the part number and supplier
of this item?
Can you help?..................."
Al Moss replied the next day as follows:-
"...............Sorry to hear you are experiencing trouble with the Seal
Kit. If you will e mail me your address I will mail you an updated
instruction sheet (revised 9/99). Yes, I am well aware that we are
running the seal at a higher than recommended surace speed, as
well as a higher temperature. However, this has not been a
problem. I know of quite a few cars, including my own TC, which
have completely successful installations and have been or are
being raced at very high RPMs and very high temperatures. There
IS NO Viton seal available in the required size. CR (Chicago
Rawhide) lists such a seal and will only make a huge run to special
order. They do list an intermediate seal rated at higher RPM &
temp and it WILL NOT WORK!!! It is designed for something like
mineral oil and fails immediately in a car engine. I am sure if you
read very carefully and follow each and every instruction, you will
have a successful installation....................."
Like Neil's friend, I know that it was properly installed and this is
borne out by the fact that it worked well for a while. I am sure that
the high temperature wrecked the seal as has been suggested.
Now it has sort of settled in at the embarrassment level.
On my new cream TC I mave just completed the motor and I have
used the Chevy seal as per this list.
The problem is what to do with my black car without having to do a
full strip down to put in a Chev seal.
This week a talked to Chris Champion, a local TD owner who made
his own Moss type modification. He found out that Toyata use a
similar system and it works fine. He has used the Toyota seal in
his car which is driven lots and hard without any problems. Their
seal has an ID the same as the XPAG flywheel flange plus speedi-
sleeve. The OD is 115 mm against the Moss seal's 120 mm. I don't
know what material has been used but it feels much softer than the
Moss seal and it has a sort of angled rough surface on the inside
which probably acts as an extra oil thrower. The seal itself is a bit
wider but Chris machined it to fit without difficulty.
My latest plan for the black car is to machine a sleeve and then to
put a thinned down Toyota seal (HTC95) into the Moss housing and
then hope for the best.
In the meantime, with club events of considerable distance planned
for the next 2 weekends, I will just hold thumbs. The good news is
that chassis and underbody corrosion aft of the bell housing will be
substantially reduced.