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MG MGB Technical - Wishbone bushes

Hi. I want to change the inner wishbone bushes. Can I just unbolt each side of the wishbone and change the bushes or does everything have to come off?
Thanks
s page

What do you mean by 'everything'?

You have to remove the spring, which needs care to do safely as there is a lot of energy remaining in the spring even with the suspension hanging down. With the car safely supported elsewhere jack under the spring pan until the damper arms just come off the rebound rubbers. Then detach the spring pan from the wishbone arms, lower it on the jack which lets the spring unload. Then remove the arms from the pivot on the cross-member.

With an anti-roll bar you may not get the drop-link out of the front wishbone arm and spring pan as it has a tapered pin that often seizes in place. But with the other side off and the drop-link disconnected from the bar the three can come off as a unit.

You may have to cut/drill/hack the old bushes out of the A-arms if they are V8, and the inner sleeve bay seize to the pivot pin.

You will probably have to press the new bushes into the wishbone arms using a socket, a vice and rubber lubricant, and lubricate the pivot pin with copper grease to prevent future seizure.

If using V8 bushes which is recommended don't tighten the wishbone to pivot nuts until the weight of the car is compressing the suspension.
paulh4

When I removed a set of negative camber wishbone arms to replace them with standard length arms a few years ago I found that the wishbone bushes had pretty much seized up.
So I replaced them with a needle roller version to prevent this from happening again.

Paul's instructions for removing the wishbone are spot on.

Cheers
Colyn Firth

Wishbone bushes seized? They're rubber or polyurethane! As such they are part of the means of isolating road noise and vibrations.
Allan Reeling

I was under the impression the original 4-cyl type were a two-part push and a separate steel sleeve that controls how much the bushes can be compressed, and stops the large washers clamping up to the sides of the A-arm eye, which would nullify the effect of the rubber. The V8 are a one-piece with integral sleeve that does the same spacing job.
paulh4

No sleeve on the 4-cyl, just rubber. The washer sits against a shoulder on the pin.
Dave O'Neill 2

Fairy-nuff. When replacing those on the V8 I had to drill, cut and file the rubber out of the eye as that had bonded to the A-arms, so grease may help there even if it isn't needed on the pin.
paulh4

Incidentally I forgot to mention one step and that is to remove the pivot both through the A-arms and lower trunnion once the spring has been removed.

While that is out check the thrust washers either side of the swivel axle bush for wear on the inner faces with a finger-nail. This can give rise to a clonk under braking. It only wears one side so you can just turn them round if needs be.

Also check the holes in the A-arms for ovalling, which comes from the pivot bolt not being fully tight, and gives rise to suspension and steering misalignment. If found then really they need replacement.

If the grease seals either side of the trunnion are in reasonable condition reuse them. Don't be tempted to replace them as a matter of course as new ones - like most rubber parts these days - have been reported as failing in months.
paulh4

As Paul has stated there was/is a problem with the bottom trunnion seals, Part number AAA1323,Moss have since stopped selling these under this part number, and are selling them under part number AAA1323X at a cost of 1-66, as compared to 95p for the old ones, I have had a few of these new type ones AAA1323X and they have been ok and have lasted.
Andy Tilney

You mentioned these last year (June 2018) saying they expand in use i.e. no longer keep dirt out and grease in and have to be replaced each year. Are you saying that's no longer the case?
paulh4

Yes they have changed them again same part number but these latest ones are ok
Andy Tilney

Thanks, worth knowing.
paulh4

This thread was discussed between 17/02/2019 and 19/02/2019

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