MatraSport Forum

What are the symptoms of worn trailing arms. Do they actually break ?. Is there any more progress on the alternative method of making them. regards  TOG

Rust is the problem. Treating them on the inside if they are rust free with Waxoyl or similar product helps. If the outside is sound, shotblasting and powder coating or alternative protective coating as you prefer is required. One area of weakness is the inside shock absorber mounting bracket which fills with dirt and starts corrosion. This needs to be kept clear of debris.

See Pictures.

GP

TOG wrote: Do they actually break?
Oh yes in the end they will breake!

Hans

a lot of weight is found by removing the rust there ;)
(http://img33.imageshack.us/img33/1841/31656345.jpg) (http://imageshack.us/photo/my-images/33/31656345.jpg/)
pic Godfried.

After welding close the gaps and make one on the lowest point so no condens and water can close in.
(http://img32.imageshack.us/img32/3662/p1010282medium.jpg)

Fill this with acid free kit (to keep dirt and moister out).
(http://img195.imageshack.us/img195/9424/p1010288medium.jpg)

Use copper grease to mount the bolts (important to get it off again after a few years).
(http://img32.imageshack.us/img32/7513/p1010286medium.jpg)

The 1.6 types do break.

Now that my hunt for pistons is over I started to take out the engine yesterday and look what I found waiting for me on the right arm. I had them refurbed only 2 years ago which is disappointing.

Any one willing to part with a half decent arm for the 1.6?

Have you made  a will yet?  ;D

GP

Those trailing arms could have broken any time under hard cornering  :-(((

I bought a lot of murena parts from a gent in Edinburgh.  He had a pair of very good trailing arms but they were for a 1.6 - mine is a 2.2 so I didn't buy them.

I will see if I can find a phone number.

I always thought the suspension on the 1.6 and 2.2 was the same, except for maybe stronger springs on the 2.2. Are you sure the arms themselves are different? If so what is the difference? ???

The arms are different. The 2.2 arms has a different shape in order to make sufficient space for the bigger 2.2 engine. Further to me the 2.2 arms looks stronger with a much bigger cress section. You can use the 2.2 arms on a 1.6 but not the other way around.

Hans

2.2 arms are way stronger then the 1.6 ones. Also the 1.6 arms look like they are made from sheet-metal and then been formed in two halves that have been pressed together, while the 2.2 arms loook like they are made from solid steel welded together.

Anyway, both of this arms will rust away, so replacement or reinforecement is a must!

Thanks for all the advice.

Having spent £700 on the refurb of the two arms (excluding bushes) only 2 years ago, and the car has rearly been in the wet and garaged, I am reluctant to spend money on an unknowen arm history.

Does anyone have experience of the Politecnic remanufatured arms please? Very expensive but are they worth it?

refurbing 1.6 arms is a lost case.
welding is impossible because of misforming of the arms.
The 2.2 arms can be welded but you need a profesional to do it.
My right trailing arm was welded by a amateur.
My wheel ended up 7 mm out of line, so i replaced it for another one.

Oh yes they are definitely different Jon.  Not only are they stronger, they are designed in a different way, and one thing no-one else has mentioned yet - the rear track is wider on a 2.2 compared to a 1.6, so although the 2.2 arms could theoretically be fitted to a 1.6 you should strictly have slightly longer driveshafts too.  Since the driveshafts can compress and extend within a limited range (and you will note they have to be compressed as you assemble the rear suspension) it is possible this will take up the extra width, but the shafts will not then be working in the correct area, or as they were before and this may lead to premature failure.

The 1.6 arm is made up of two pressings joined along the flange.  The 2.2 arm is made of four flate plates welded along the corner joins to make a box section.  Both rot owing to the fact that when welded, any protective paint on the inside is burnt off leaving it unprotected and as we know, no manufacturer ever bothers to pump in a protective cover afterwards!  So the moisture gets in and does its worst.

Before fitting replacement arms you always want to apply as much protective to the inside as possible, and then re-apply more at intervals during their life.

Roy