20 replies to this topic

[minstix]

So are you saying that your NOS 21A1889 pins do have the welded on washer?

 

I've tried fitting one of the arms with one of my original (washer welded on) pins this morning using new standard Mini Spares Centre tapered rubber bushes and it all went together ok. The inside flat of the washer sits almost against the subframe, probably in contact around the back. My concern now is that when the nut is tightened the arm moves by slippping against the rubber.

 

I was under the impression that the rubber should grip the inner surface of the arm and the metal tube inserts inside the bushes should also not turn on the pin and that all movement would be be accommodated by the bending/twisting of the rubber itself. Am I wrong in this assumption? It seems to me that the tube inside and the pin don't make a bearing of any sort and if the arm slips on the rubber it will just cause friction which will mean it would soon fail.

 

I'm wondering if the washer is prventing the bushes being squeezed enough to lock them solid?

 

Any thoughts on all this?

Edited by minstix, 13 February 2023 - 10:14 AM.

[Spider]

So are you saying that your NOS 21A1889 pins do have the welded on washer?

 

I've tried fitting one of the arms with one of my original (washer welded on) pins this morning using new standard Mini Spares Centre tapered rubber bushes and it all went together ok. The inside flat of the washer sits almost against the subframe, probably in contact around the back. My concern now is that when the nut is tightened the arm moves by slippping against the rubber.

 

I was under the impression that the rubber should grip the inner surface of the arm and the metal tube inserts inside the bushes should also not turn on the pin and that all movement would be be accommodated by the bending/twisting of the rubber itself. Am I wrong in this assumption? It seems to me that the tube inside and the pin don't make a bearing of any sort and if the arm slips on the rubber it will just cause friction which will mean it would soon fail.

 

I'm wondering if the washer is prventing the bushes being squeezed enough to lock them solid?

 

Any thoughts on all this?

 

The sleeves in the 2 bushes are ever so slightly longer that the plain shank of the pin on which they mount. When it's all done up correctly, the sleeves are pinched and don't turn. Many in these parts have stripped the threads on the Pin (the type that has the washer) thinking they need to be done up until the washer sits flat against the subframe,,,,,

And just as you are thinking, the rubber is gripped inside the arm, all the twisting and take up is in the rubber itself. This is where the Poly Bushes fail as they won't twist.

The P/N on the Pins we had here is 21A1889.

[minstix]

Great, thanks for the useful information.

 

I read in an old service manual that you are suposed to the final torque up of the nuts once the car is sitting on its wheels so the arm I guess is sitting in its central position before the rubber and metal tubes get gripped tight. how you get a torque wrench in then will be interesting but I'll give it a go.

 

Thanks everyone for your input on this one,

 

Steve

[Lplus]

Great, thanks for the useful information.

 

I read in an old service manual that you are suposed to the final torque up of the nuts once the car is sitting on its wheels so the arm I guess is sitting in its central position before the rubber and metal tubes get gripped tight. how you get a torque wrench in then will be interesting but I'll give it a go.

 

Thanks everyone for your input on this one,

 

Steve

Jack up under the lower ball joint untll the suspension takes the load.  Should be near enough.

[GraemeC]

Or use a crows foot spanner.
Or do as 99% of people will and use feel and judgement that it is tight without stripping thread. To be honest you’d be hard pushed to overtighten that nut with a spanner, or at least not to the point of damaging anything.

[minstix]

Now here's the issue I have that got me to start this thread.

 

I've got a set of new standard Mini Spares Centre rubber bushes, the tapered type. Fitting them to the subframe using the original 'welded on washer' type of pins, no matter how much I tighten up the nut, the metal tubes still turn on the pin. The welded on washer is not stopping the squeezing of the rubber further as it's not quite in full contact with the subfame face. I now realise that the welded on washer is irrelevant to the problem. It's all about the length of the rod that the bushes sit on when it's in the subframe and the nut is on.

 

The problem for me seems to be that the inner metal tubes inside the new bushes are very slightly short. All four are the same length. When two are added together they come to a total length of 39.2mm.The rod they sit on is 39.5mm. Not much in it but enough that the metal tubes can never be clamped together tight inside. If I try to tighten the nut to try and clamp them that's not going to happen and I would just strip the thread. So I don't want to do that.