17 replies to this topic

[MikeJE]

My '62 Woody rear driver's side suspension went a bit iffy a couple of months ago, dropping so the wheel arch was nearly touching the wheel. I assumed it was the suspension rubber so replaced both rear cones and associated knuckles and readjusted the Hilos. However, after a short drive the same thing happened, with the arch nearly touching the wheel. I now suspect the subframe has given way where the knuckle inserts but will need to dismantle around that area to see if that is the case.

 

The subframe itself otherwise appears to be in really good condition so I wondered if this was a common issue?

 

Also, if I do need to replace the subframe are the Minispares or Minisport or other own brand suitable or am I better off getting a genuine replacement?

 

As always, very grateful for the forum wisdom and advice

 

Best wishes

 

Mike

[sonscar]

The knuckle fits into the radius arm?The top or bottom subframe web being corroded may cause this,Steve,,

[MikeJE]

The knuckle fits into the radius arm?The top or bottom subframe web being corroded may cause this,Steve,,

 

Many thanks, Steve, of course the knuckle doesn't go into the subframe: I don't know why I thought that. Yes, I will have to have a proper look to see if there is something awry with the subframe, although everything I can see without dismantling looks good. 

 

Best wishes

 

Mike 

[mini-mad-mark]

Subframe mounting point corroded  in the heelboard?

Allowing the whole subframe to push up with the weight of the car on it but when you jack it up the subframe falls down to more or less its correct position so with a cursory inspection everything looks normal (as its hard to see the heelboard with the subframe in the way)

[Spider]

Check the Subframe for sure, but also check the Swing Arm Shafts, Bearing & Bush and also the inboard hole in the Subframe where the Shaft goes through, these can elongate and it doesn't take much to get a fair loss in ride height. When checking the Shafts, look in particular at the inboard end as the threaded section can and do bend.

[sonikk4]

You say you checked the knuckles but did you change the nylon cups??

[MikeJE]

You say you checked the knuckles but did you change the nylon cups??

Yes, changed them as an assembly. I did wonder if they had broken inside which would cause the suspension to drop but they appear to be fine. 
 

Thanks, Spider, I will check those in particular. I suppose one way of doing that is to see if there is any lateral movement.

 

And thanks Mark, I will check the heel board, too and the subframe mountings.

 

Very grateful to everyone for taking the time to respond. It’s much appreciated. I will report back on my findings….

 

Best wishes…and stay safe

 

Mike

[mab01uk]

I think if there was any serious enough corrosion of the rear subframe to cause suspension collapse you would have noticed it when you replaced both rear cones and associated knuckles and readjusted the Hilos....but all the points mentioned on this thread are worth checking. Let us know what you find.

Edited by mab01uk, 13 December 2021 - 10:51 PM.

[MikeJE]

I have checked everything and cannot see any damage to the subframe, heelboard or swinging arm.

 

What I have found is that when I jack up the nearside to adjust the Hilo the connecting bar (trumpet) and cone are tight in place. When I jack up the offside - the side with the problem - the cone is really loose to the point of nearly falling out and the bar/trumpet, too, is very loose. When back on the ground it all goes back into place and the ride height is fine, but this is what happened before but when I went over a bump it collapsed again.

 

I would have suspected the knuckle joint having collapsed, but it is new and feels to be OK when moving the bar around.

 

Now totally at a loss and really very grateful for any further thoughts.

 

Best wishes

 

Mike

Edited by MikeJE, 14 December 2021 - 04:37 PM.

[Spider]

That's a fairly big change.

What Hilos and extension bars have you got fitted ?

 

I should have included it when I mention about checking the Arms and Shaft, that you usually need to get in there with a lever to try and push the arm around in all directions as the pressure from the rubber tends to mask any movement.
 

[GraemeC]

Do you have locknuts on the HiLos?  I wonder if the threads in the alloy part are so corroded that the make thread is pushing past the female?

[MikeJE]

Thank you Graeme and Spider. Yes, it's strange as the rubber cone just falls about when that side is jacked up. Not sure what make the Hilos are, but they have been on the car for the 9 or so years I have had it without any problem. The suspension on that side just dropped when I was on my way back from Brooklands and I assumed it was the cone(s), but appears not. Yes, they Hilos have locknuts and the threads are tight into the alloy cup. Not sure what to do next: I do wonder if the swinging arm has broken somehow where the knuckle inserts, although surely that would show up as soon as the car is back on the floor. Many thanks indeed for all your thoughts. I think I will take everything out and order a new knuckle in case it's that.

 

Many thanks again, all, and best wishes

 

Mike

[Spider]

,,,,,,, Not sure what to do next:,,,,,,,,

 

Mike

 

I'd suggest removing the Arm. It's not a huge job and I'm sure it will be quite reviling.

Just your description there that it suddenly dropped, I'd say something worn through or broken.
 

[nicklouse]

 How worn was the old cup?

[MikeJE]

 How worn was the old cup?

 

Do you mean the cone or the knuckle? The old cone did seem quite worn compared to the new one. The knuckle seemed OK, but difficult to tell as it was damaged getting it out. I think I will remove the arm as Spider suggests (though not looking forward to bleeding the brakes again as it took ages last time to get even a firmish pedal). Many thanks once again for your thoughts

 

Best wishes and do take care

 

Mike