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MOT failure: front upper suspension arms

Posted: Fri Jul 24, 2015 1:19 pm
by thesmithsUK
Hi,

1968 Convertible just failed on (amongst other things):

"Nearside front upper suspension arm rubber bush deteriorated".

Is this an easy fix?

Can anyone send me a link to the part I need to order?

Or even a diagram that shows me what part this is?!

Thanks,

Geoff

Re: MOT failure: front upper suspension arms

Posted: Fri Jul 24, 2015 2:09 pm
by les
He could mean the small rubber dust/ grease seal, around the bottom of the top trunnions. If not the rubber bushes that go through this trunnions. Maybe you could ask the mot man to be more specific. Probably the latter suggestion.

Re: MOT failure: front upper suspension arms

Posted: Fri Jul 24, 2015 2:29 pm
by bmcecosse
If it's the bushes connecting the arm (and he does say 'arm') from the damper to the kingpin - then yes - easy fix - and be sure to use poly bushes here - they make a huge difference to the precision of the handling. What else was on the list ? items 23 in this diagram - but be sure to buy POLY - not rubber... Do the other side too when you get a chance after the MOT is secured.

Re: MOT failure: front upper suspension arms

Posted: Fri Jul 24, 2015 3:22 pm
by thesmithsUK
Thanks bmcecosse.

You refer to a diagram?

Other items: lost of welding, one TRE, a tyre, imbalanced brakes across an axle...

Re: MOT failure: front upper suspension arms

Posted: Fri Jul 24, 2015 3:29 pm
by panky
I've just done ( literally just come in from the garage) the upper trunnions with poly bushes. I did them last year with rubber ones and they had deteriorated alarmingly :o so it's poly all the way from now on.

Re: MOT failure: front upper suspension arms

Posted: Fri Jul 24, 2015 4:16 pm
by bmcecosse

Re: MOT failure: front upper suspension arms

Posted: Fri Jul 24, 2015 5:31 pm
by thesmithsUK
That's the one! Just spoken to the MOT guy to confirm.

Both sides need doing, so will order 8 (poly rather than rubber, as advised).

I've noticed that the nut on one side has some sort of retaining pin:

Image

Does anyone know how to deal with these?

Re: MOT failure: front upper suspension arms

Posted: Fri Jul 24, 2015 6:01 pm
by Matt
Yes... don't take that side off (no need too)

But its called a split pin, bend it so the legs are straight and pull the eye with pliers etc

Re: MOT failure: front upper suspension arms

Posted: Fri Jul 24, 2015 6:05 pm
by panky
A good wire brushing and soaking in release oil, then straighten the two bent ends out, grip the eye with a pair of pliers and pull. With any luck it will come out but it might be a bit of a struggle, what I've had to do in the past is to knock a thin screwdriver or spike through the eye, this then gives you something to tap against with a hammer. Failing that you may need to just shear it off by undoing the nut then drill the hole out again.

Re: MOT failure: front upper suspension arms

Posted: Fri Jul 24, 2015 6:14 pm
by philthehill
I suspect that the split pin through the castellated nut on the side that does not have one has been sheared off and not replaced. Both sides should have castellated nuts (Pt No: AJD8408Z(MOSS)) and split pins (Pt No: BHF503 (MOSS)) fitted.
As above remove nut find remains of split pin and knock out or drill out. Replace split pins on both sides with new - never reuse an old split pin.
If you are replacing the top link/arm rubbers (Pt No: ACA5282 (Rubber) or ACA5282SPK (Poly) (both MOSS Pt Nos)) you do not need to remove the top pin (Pt No: AAA3653 (MOSS)). The top trunnion can with the outer bush removed and a little pressure be turned and twisted over the end of the top trunnion pin with little difficulty.
Yes - poly bushes are best :D

Re: MOT failure: front upper suspension arms

Posted: Fri Jul 24, 2015 7:07 pm
by bmcecosse
You only need FOUR - not eight... Moss sell them as a kit of 4....that's what to get. Of course you don't need to go to MOSS - I just show that diagram because it is one of the best - and explains how it all goes together.

Re: MOT failure: front upper suspension arms

Posted: Fri Jul 24, 2015 7:59 pm
by thesmithsUK
Ah yes, 2 per side.

I notice they seem A LOT cheaper at Bull Motif...

Re: MOT failure: front upper suspension arms

Posted: Fri Jul 24, 2015 8:58 pm
by bmcecosse
Buy there then! Although you may get what you pay for..... But note MOSS have a 17% off sale going this weekend. As another has already said - DO NOT undo that rusty nut/pin - it's the other end nut - should be held with a lock washer - that you will release. Then with a secure jack under the lower suspension arm, lift it slightly - and twist the top trunnion off pin.

Re: MOT failure: front upper suspension arms

Posted: Sat Jul 25, 2015 12:15 pm
by thesmithsUK
Forgive the dumb questions. I'm looking at MOSS diagrams, the workshop manual, etc.

This is as far as I've got (nut and washers removed):

Image

Rubber bush clearly perished.

Jack in place supporting lower arm.

But what's my next move?

Re: MOT failure: front upper suspension arms

Posted: Sat Jul 25, 2015 12:31 pm
by panky
It makes it easier if you can dig out the remains of the old bush with a screwdriver, that gives you a bit more room to twist the leg off the pin. It needs a little bit of effort so don't be too gentle.

Re: MOT failure: front upper suspension arms

Posted: Sat Jul 25, 2015 12:33 pm
by The vast minority
Just wiggle the trunnion off the pin now, it's easy as putting a hat on your head,
Wiggle it off, fit new bushes and twist, wiggle back into position.

Al

Re: MOT failure: front upper suspension arms

Posted: Sat Jul 25, 2015 1:38 pm
by thesmithsUK
Thanks for the continuing input...bear with me!

So, this is the one on the passenger side. Outer nut, washers and rubber bush removed. Inner bush still in situ. Am I right in thinking that I now need to pull/wrestle the top trunnion in the direction of the arrow, over the end of the pin?

Image

Re: MOT failure: front upper suspension arms

Posted: Sat Jul 25, 2015 2:27 pm
by bmcecosse
Exactly.

Re: MOT failure: front upper suspension arms

Posted: Sat Jul 25, 2015 3:02 pm
by thesmithsUK
Success!

The key was raising the damper arm clear of the rebound stop. Once I'd done that, the upper trunnion popped of the pin easily enough.

Many thanks all. That's another piece of knowledge added to the small-but-growing MM list!

Re: MOT failure: front upper suspension arms

Posted: Sat Jul 25, 2015 3:36 pm
by bmcecosse
I did say earlier to jack it up... Well done!