MatraSport Forum

Hi everybody, could somebody tell me the exact inside diameter of the trailing arms,
where the silentblocks fits in, or the outside diameter of the silentblock ?



Finn  :)

Tomorrow Finn, when I've had chance to measure up my spare original Matra t/arms.

Roy

The outer diameter of the bushes are 33mm Finn.  They should be an interference fit in the arms.  The bores on my original new t/arms are 32.8mm although there is some paint there for protection so they could be fractionally larger.  I'm never comfortable with metric figures at tiny amounts having been trained years ago when we still worked in imperial!  So I still think in thou'.  However, 0.2mm (10 thou) interference sounds about right.

Roy

Hi Roy, thanks a lot for the information ! What should I do without this forum and
somone like you.

Concerning Inch/Metric, I have it the other way round  ;D

Thanks !

 Finn

does anyone know the exact dimensions for the bushes?    inner,outer etc?

and is there  metallcase around the rubber or is it free?

Since I stated an interference fit, there is obviously a metal case - if the outside was rubber you couldn't have a 10 thou interference measurement. :-)

The bushes are fairly normal metalastic type bushes with metal case and metal tube in the centre and bonded rubber in between.  As stated the outside diameter of the bushes is 32.8 mm  The longer bushes have a flange at one end.  The shorter bush outer casing is 52 mm long and the centre tube is 60 mm long.  The longer bush outer casing is 65 mm from flange to opposite end and the centre tube is 75 mm long.  The hole in the tubes is designed to take the 12 mm bolts that bolt through them.

Roy

just meassured and on my arm the inner tube is 52mm long and the outer 61mm,
or do you mean the inner bush is 75mm long total and the outer is 65mm total (inner metallic tube)?

Not sure, but remember the trailing arms for 1.6 and 2.2 are different... Though the bushes are the same I believe.

If you like I can measure both the 1.6 and 2.2 arms and bushes for you?

By the way... how is your HDI swap proceeding Waldo ?:)

yes i do have the 1.6.
I would be very happy if you could meassure the bushes  :)

You are confusing things by using the terms inner and outer.  These could mean the position on the car OR the bush.

What I stated was correct - I have some new bushes right in front of me to take the measurements.  The tube in the centre of each bush protrudes from each side, so the tube is longer than the bush.  My measurement were approx. and taken with a ruler so when I said the short bush is 52/60 mm and the longer one 65/75 mm long these are nominal figures, and if you have used a vernier your figures may be more accurate.

Roy

Regarding trailing arms. Does anyone have a drawing of the 2,2 trailing arms, showing all dimensions? Unfortunately I don't have accessto an old set.
My friend Jan and I have been discussing the possibility of making a jig to hold stainless steel bushings with the right measurements and then welding stainless tubing between them, thus making completely stainless trailing arms.
Any takers out there if we succeed?  ;)

Mine are almost brand new.. but I applaud the idea!.
I was actually considering something similar, since about half the people in my class are certified black smiths :)

ive come in contact with someone who might be able to produce them at lower cost then the original ones.

ok, these drawings are exact.

If more people are interested I can probably supply complete set, 2 of each 4 total, for around 60-70euros. 

Jon Waywadt wrote:
Does anyone have a drawing of the 2,2 trailing arms, showing all dimensions? Unfortunately I don't have accessto an old set.

A few years back we had some set of 2.2 trailing arms made in Denmark. A machine shop known to one of our members laser cut pates for ten set of trailing arms. As a part of the original trailing is needed to produce the new set, we handed over our old set and had a new set made. I got the first set myself.
The steel plate for our reconstructed trailing arms had a better quality than the original and as we used a thicker plate the new trailing arms only had one layer of steel plate all way around. The original trailing arms had two layers on the sides.
The original trailing arms rust mainly from inside and between the two layers of plate.
Therefore I closed my trailing arms completely, drilled a hole on the upper side poured in some rust protecting oil, and then closed the hole with a plastic plug. Not stainless but I am sure that my trailing arms “will last forever”

Maybe the drawings or files for controlling the laser cutting machine will still be available at the machine shop.

If you are reproducing some trailing arms please have in mind that stainless steel does not have the same strength as normal steel.

Regards Hans

just meassured the bushes and also noticed they have number 34 on them. can anyone confirm if they also have that number stamped on the side of the bushes? its on the rubber.

i wounder if someone might have used 34mm bushes on these trailingarms...

Thanks Hans. Yes, I have also learned that the strength of stainless steel is not as good as normal steel. I will have to calculate how much thicker tubing or plate we would have to use to compensate. I also want to make sure that they do not get heavier than the originals.

I was not aware that the original swing arms had double plate on the sides. That makes it much more difficiult to get a good rust protection inside if I chose to restore them rather than making new ones.

Do you still  have the contact information to the machineshop that made the new arms?

just updated my earlier post with exact drawings of the bushes and more info :)

You are confusing things by using the terms inner and outer.  These could mean the position on the car OR the bush.
[/quote]

Only in England, Roy.

I still can't get my head around the term nearside, offside, inner and outer ... it all starts by having to drive on the wrong side of the road you see :-)   

/Lennart  (ducking while jumping into the flameproof suit :-) )

LOL


Now these are two terms that really should never be used in my opinion as so many get it wrong and you can be looking in the wrong place!  But they have become so common to use that for those of us that do understand them it is too much to try to change and not use them.

They really mean 'with the car facing forward, nearside to kerb and offside from kerb' and that is it.  This means that in the UK nearside is the left of the car, and offside is the right.  It doesn't matter whether the car is LHD or RHD or even centre drive (McLaren F1...) it is the same.  That was one reason for the term the side being described did not have anything to do with the steering position.

However, on the continent where you all drive on the wrong side ;-) ... sorry the right side of the road, the nearside (to the kerb remember) is the right of the car and the offside is the left.  Doesn't matter where the steering wheel is, that is not the point.  Simple really but as you can see easy to confuse too.

This is why I try to stick to Left and Right sides but sometimes I slip and use the nearside/offside terms.

Roy

Anybody know the dimensions of the bolts thats used to mount the traling arms?
I'm thinking that some titanium alloy bolts might be available... they should easily be tough enough, and have up to four times the corrosion resistance of stainless steel ones.

They are M12, with a 1.75mm pitch thread.  The long one is 110mm and the shorter one 90mm, both lengths exclude the head.

Since the trailing arms being made on the continent are in fact incorrect, as well as costly, I am investigating having some made in the U.K.  Now it may turn out that it will not be economic, or there is insufficient demand and to make the unit price reasonable we need a minimum number, but at this stage it is only an investigation into the possibility, so nothing to lose yet.

Since you say that some drawings had been made Hans, and maybe are still available, would you be prepared to find out if they are available, and if they would want any charge to let us have copies?  Thanks.

BTW what were those Danish trailing arms like?  Good quality and accurate?  Did anyone recheck their suspension alignment afterwards to make sure the geometry was exactly the same as the original?  How did the cost work out - similar to those commercially sold or more expensive (or cheaper)?

If anyone is interested or in need of new rear trailing arms I would be pleased to hear from you (direct email please) and I will keep you informed of any progress.

Roy