This is a follow-up to the earlier post I made (included below) regarding my
recent experience with seat diaphragms in my TR6. Hopefully it will be of
interest to others pondering replacing these items.
Note: this is not intended as a slam against TRF or an endorsement of Moss.
It is merely a "field test" based on a very limited sample set. YMMV.
As the post below states, I got two diaphragms from TRF and upon installing
one of them, it split. I subsequently found out that diaphragms are one if
the items TRF has made to their specs (in Taiwan). Further, Moss (and others
I'm sure) sell diaphragms made in England. I ordered and received two such
diaphragms from my local Moss distributor. There definitely is a difference
in the two products.
The main differences are the thickness, size and elasticity of the two
products. The TRF one is somewhat thicker and has a larger area (when not
installed). It is also much less elastic. The Moss one is slightly thinner,
quite a bit smaller and much more elastic. The support seems to be about the
same with both. The thing I didn't like about the TRF one was the
"stiffness" compared to the Moss one. It almost seems as if the TRF ones are
made of a lower grade (elastically speaking) of rubber/plastic. The Moss
ones fell more supple and stretchy. I don't think the thickness is the only
reason for this -- I think the material also plays a part.
In keeping with the originality and accuracy claims made by TRF, their
diaphragms have the extra holes for the seat switch fitted to later cars.
The Moss ones have no such provision. No sweat for me but the real purists
might want to take note.
In all fairness to TRF, they were very gracious when I called about my split
diaphragm and said no problem just return it. They also stated they sell
about 1500 per year and have very few problems. Maybe I just got a bad
example. I never tried installing the second one I received from them to see
if too would split.
PS. I found it better to reuse the original hooks rather than the new ones
supplied. They have an additional bend which makes installation a little
easier cuz the rubber does not have to stretch quite as far (almost 1/4"
PS2. I'm not (personally) looking for testimonials of TRF diaphragm success
stories (although others may want to hear them). I'm just passing on my own
experience, that's all. And I have no interest in Moss or TRF other than
being a customer of both and happy they supply parts for these cars.
Peter Zaborski CF58310UO
> From: Peter Zaborski
> Sent: Monday, February 15, 1999 11:51 AM
> There's been a lot of discussion lately about TR6 seat foams.
> I thought my slightly saggy seat was in need of a rebuild. It
> turns out a new diaphragm is all I need. I installed one on
> the driver's seat and the seat is back to normal. There is a
> catch however...
> First, my car is a late, late TR6. Which means it originally
> has the webbing type of seat support in place of the rubber
> diaphragms (check the TRF catalog for details). A couple of
> years ago one of the webbing straps on the driver's seat
> broke. I had it replaced at an upholstery shop. I don't think
> they did a very good job as the seat was still somewhat soft.
> So recently I got some new diaphragms from TRF. I began with
> the driver's side seat but in order to install the diaphragm,
> I needed to drill some new holes in the frame -- the original
> holes from the webbing frame did not match the diaphragm
> holes. No biggie, I drilled the holes and the diaphragm went
> in without a hitch. The seat is way more comfortable now and
> I am sure this is the cure.
> However, I just noticed that the diaphragm has already
> started to split in a small section of the middle part (not
> adjacent to any of the clips). I am certainly no heavyweight
> (175 lbs). Did I get a defective part from TRF or are the new
> diaphragms really that cheap? What is the opinion of the list
> on the replacement diaphragms? Are there better sources than
> TRF or are all the diaphragms the same?
> FWIW, I plan to call TRF tomorrow and I'm sure they will
> rectify the situation but what I really want is to make the
> repair and forget about it -- I don't want to install cheap
> parts which will just fail shortly. I could always have the
> webbing straps rebuilt with heavy duty materials but the
> diaphragm seems like a better solution (if it works properly!).
> Any info greatly appreciated.
> Peter Zaborski CF58310UO