King Pin Top Bolt

Technical MGB discussion
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Bumpa
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Joined: Sun Dec 13, 2020 9:58 am
Forename: Mike
Surname: Howlett

King Pin Top Bolt

Post by Bumpa »

Trying to dismantle the front suspension on my project MGB. All the front suspension parts look like they've been at the bottom of the sea for a while. At the moment I am trying, without success to remove the top bolt that connects the shock absorber arms to the king pin. I have a jack underneath to take the load from the spring and I got the nut off but cannot persuade the bolt to move at all, even with a BIG hammer. The head of the bolt is captive against the casting so I can't try to turn that end. Any suggestions?
Mike
1969 MGB GTV8 3.9 Conversion, 1977 Triumph Dolomite 1850HL, 1971 MGB roadster undergoing restoration.
Ian Fozzard
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Forename: Ian
Surname: Fozzard

Re: King Pin Top Bolt

Post by Ian Fozzard »

Mike, when faced with this I've tapped an old cold chisel between the two arms to loosen things up a little. If you can get the smallest gap you can pour Plus Gas or similar in there to do it's work.
Ultimately I think the arms can be removed, but I've never had to do that.

Ian F
1972 BGT, Blaze, Navy trim, recessed grill
1961 Midget, 948cc, Clipper Blue, Blue trim and weather gear
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Paul Hollingworth
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Re: King Pin Top Bolt

Post by Paul Hollingworth »

I had one side of mine that wouldn't shift. The problem is that its not firm enough for a strike from a lump hammer to shift it. No amount of soaking with penetrating oil helped. I ended up taking one of the arms off the damper and with the four retaining screws out I could push the rubber bushes through. With the damper on the bench I was able to cut through the pin with an hacksaw. The annoying thing was that I had fitted V8 bushes 18 years previously. I'm sure I greased the pins but they had seized solid to the sleeves in the bushes. The new polybushes I put in seemed to have stainless sleeves and so with plenty of grease shouldn't seize again.
1971 MGB roadster & 2006 MGTF
Vic Butler
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Location: North West Hampshire

Re: King Pin Top Bolt

Post by Vic Butler »

A copper based grease is best.
1977 Stage 2 MGB GT
1975 SWB Series 3 Land Rover with a later 2.5 petrol engine
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Bumpa
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Joined: Sun Dec 13, 2020 9:58 am
Forename: Mike
Surname: Howlett

Re: King Pin Top Bolt

Post by Bumpa »

Nothing I tried worked at all so I cut through the bolt both sides of the trunnion with a hacksaw. It was a bit easier than it might have been as the car has no front wings at the moment. Even then, with it on the bench, although the end with the nut came out of the shocker arm, the head end wouldn't budge and I had to resort to drilling through it enough to make it collapse when I hit it.

I'm now trying to get the old bushes out of the inner ends of the lower arms. They may be old poly bushes as they have a steel sleeve insert. Old cars - who'd have them?
Mike
1969 MGB GTV8 3.9 Conversion, 1977 Triumph Dolomite 1850HL, 1971 MGB roadster undergoing restoration.
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