Bent radius arm

[Plank]

I have this weekend changed the OSR radius arm on the 998 for anouther one out of my shed. It was bent to the extent that the tyre was badly scrubbing off on the outside edge and you could actually see that the wheel was sitting at an angle. Thinking back I did a side ways slide a couple of months ago when trying to brake hard on a lane and skidded on gravel.
I have had many many minis over the last 27 years (yes I am that old)and have never bent a radius arm before, has any one else heard of this?

[cone]

Yes , seen quite a few , looks a solid item but bends quite easy .

[Plank]

Well you live and learn. I thought they were unbreakable being cast iron.

[DanGT]

I have bent the radius arm on my mini. 360 spin stopping on the kerb. Some one told me you could see the car lift in the air? Found out one of the front shocks had gone and the othere was wroking very well.

[GTRMikie]

I bought a reconditioned arm from a respectable mini spares dealer. When I put it on the car it had about 10 degrees positive camber! They changed it for a straight one without a fuss.

[Mr2Mike]

Quite a common problem, if you ever see a mini crabbing chances are it has a bent radius arm.

[DanGT]

Radius arm monting (people weld them on with out truing up the arm) out of line puting the arms out of line I have seen a lot.

[Cooperman]

I've heard of them allegedly bending but have never seen a bent one yet. I have been navigating in a rally Mini which had one snap off on a stage in a rough forest - we were off the road at the time as well and still doing about 60 mph! One might expect the mounting brackets to bend, or the sub-frame to distort, or the axle shaft in the arm to bend, but for a cast arm to bend would seem unusual as cast iron just fractures.

[Mr2Mike]

Cooperman said:

I've heard of them allegedly bending but have never seen a bent one yet.

A friend bought a mini that turned out to have a 1/2" wheel spacer fitted to one rear wheel to prevent the tyre rubbing on the shock! The radius arm was well and truly banana-like, putting the new (s/h) replacement on top of the original clearly showed the difference.

At the time I was quite surprised it had bent rather than broken, but in hindsight I wonder if they are cast from a malleable iron? Considering the the thin wall section and the application (I'd far rather have a bent suspension arm than a sheared one!) it would make sense.

[Cooperman]

I guess that's right, Mike. Considering the abuse I've given my Minis over years of rallying I'm surprised I've not seen a really bent one, only a snapped one. In that instance we tried to gas-weld it. It seemed to take, but broke again 1/4 of a mile down the road. Did they ever change the material specification? That could be the answer as the early ones don't seem to have bent easily.

[DanGT]

The one I bent on my mini (I bent the shock, sub frame and the shock mounting point and had to have the body jigged) was from the 80s. It looked ok until the new sub frame was on and then you could see (easly). It was a very hard hit and I have never bent one racing.

[casbar]

The cooper I bought for my son in June had a bent radius arm. People tend to jack the car up on the radius arms, that will bend them nicely.

I fitted a couple of more substantial adj ones.

[cone]

casbar said:

The cooper I bought for my son in June had a bent radius arm. People tend to jack the car up on the radius arms, that will bend them nicely.

I fitted a couple of more substantial adj ones.

That'll be the tie bars you mean . Radius arms (rear swing arms) are at the back .
Peter I know one would think something else would give first , but compare two in a "jig" (vice) and you can spot a bent one against a known good un .

[casbar]

Yep, your right, didn't read the post correctly. Doh!!