18 replies to this topic

[Tomf]

Well i had play in one of my radius arms, so i stripped it down today to find that it has two roller bearking.

Now all the repair kits i have seen have one roller bearking and one solid that needs to be reamed.

So why is mine different? and what do i do in the ways of a replacment breaking?

The arm has come of a mini.

Edited by Tomf, 29 June 2009 - 08:05 PM.

[Frog]

Well i had play in one of my radius arms, so i stripped it down today to find that it has two roller bearking.

Now all the repair kits i have seen have one roller bearking and one solid that needs to be reamed.

So why is mine different? and what do i do in the ways of a replacment breaking?

The arm has come of a mini.

I have stripped a subframe for my mate & he to had x1 radius arm as normal, one bush one bearing the other had 2 bearings, I had heard of people in the past machining out the outer edge of the radius arm to fit the other bearing but hadn't come accross it until then. In theory it would never wear if kept greased !! Troubleis no kits come with 2 bearings that I know of so either got to buy a second kit or source a bearing.

[Dan]

The arm you have is a cheap re-con. They are common, the only problem with using two roller bearings is that they wear out faster than the bush would. It's a poor engineering solution. I believe that once the arm has been machined for roller bearings at both ends it cannot be refitted with a standard bush but I might be wrong about that.

[Tomf]

Ah dam, looks like ill have to try and source two roller bearings then.

I did think it was a bit strange as i always thought that one end had a smaller bore than the other but i measured it and they were both the same.

Thanks for the advice.

[nicksuth]

Ah dam, looks like ill have to try and source two roller bearings then.

I did think it was a bit strange as i always thought that one end had a smaller bore than the other but i measured it and they were both the same.

Thanks for the advice.

Whats the manufacturers reference on the Needle Roller Bearing ???

[MRA]

As Ethel says its a cheap trick created by a bodger who only wants your money.... It will not last as the point loading on the bearing rollers is far too high, this will lead to accelerated wear, on the other hand I don't think you need to worry about fitting a bush as I think they are the same outer diameters..... I can check this tommorrow

Regards Martin

[Tomf]

Thanks for the information.

It would be good to know if the outer diameters are the same, as im sure i read somewhere that one end was smaller, but hopefully thats just the internal diameter.

[MRA]

Just checked a new kit, the bearing and bush are quite different in size....... which also means that a lot of the strength of the radius arm has been machined away to fit the second bearing

[Nightrain]

IIRC the metro had bearings at both ends, seeing as there aren't many metro's left. There's probably an excess of radius arm kits kicking about/been bought very cheaply to bodge mini arms.

[Ethel]

Did I reply to this?

Would a refurbisher machine out a radius arm as a cost saving measure?

It would be a way of reclaiming arms when the pin has worn right through the bush. I don't know if it would be worth anyone's while to process all arms the same as a streamlining measure.

Metros do have 2 rollers, in longer arms on a heavier car.

[Tomf]

ill measure the bores of both ends again to double check. and ill post up the measurements.

[MRA]

IIRC the metro had bearings at both ends, seeing as there aren't many metro's left. There's probably an excess of radius arm kits kicking about/been bought very cheaply to bodge mini arms.

They are different lengths

[MRA]

Did I reply to this?

Would a refurbisher machine out a radius arm as a cost saving measure?

It would be a way of reclaiming arms when the pin has worn right through the bush. I don't know if it would be worth anyone's while to process all arms the same as a streamlining measure.

Metros do have 2 rollers, in longer arms on a heavier car.

The metro refurb kit has the oversize tooling and the sleeves for when they wear through...... I don't ever remember there any requirement for the Mini ones.

The metro kit has these oversize sleeves because they do wear out quicker, and when they wear out they usually damage the arm.

Yes metros have rollers........ however an OLEO leg of an aircraft will have bushes NOT bearings, as they transmit loads more evenly, and don't wear out so quick.

Edited by mra-minis.co.uk, 30 June 2009 - 03:45 PM.

[Nightrain]

What about some bush kits, to convert to a bush at both sides like the very early mini radius arms martin.

[MRA]

Yes the early ones did have a double bush instead of the bush and bearing arrangement...... but they are pretty rare (we have the kits though ) the mod was for reliability.... I seem to recall that it was something to do with getting the grease to the farther most bush.... which lead to accelerated wear on the inner bush.

A later arm would need to have a sleeve to accept the inner bush though

Regards Martin