King pin shims.

Technical MGB discussion
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Rommel
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Joined: Mon Feb 26, 2024 6:14 pm
Forename: Tony
Surname: Bave

King pin shims.

Post by Rommel »

So I have some vertical movement in my stub axles, so going to add some shims under the top trunnion should I also replace the bronze thrust washer? is this subject to much wear? or just add more shims? In the past with king pin issues I have just replaced the whole assembly with recon units but everything else is in good order just a bit of lift in stub axle, also can anyone tell me the thickness of a new bronze thrust washer? not taken it apart yey all soaking in WD40 at the moment.

Thanks in advance.
Ian F
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Re: King pin shims.

Post by Ian F »

It's a long time since I did this job ( due to relatively low mileage in recent years) and I was not spending a lot of money on the BGT.

However, my view is that the thrust washer is exactly that - just there to act as a bearing surface. I still have a string of shims of different sizes to take up the slack to the correct specification. They are steel. So as long as the bronze thrust washer still looks reasonable, all you should need is a set of steel shims/washers of the correct size.

Ian F
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1972 BGT, Blaze, Navy trim, recessed grill
1961 Midget, 948cc, Clipper Blue, Blue trim and weather gear
Rommel
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Forename: Tony
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Re: King pin shims.

Post by Rommel »

Ok so just done this and found that both the thrust washer and shims are subject to wear, new thrust washer significantly thicker than the old one.
So new washer and two new shims (57 thou) gave correct clearance of 0.02 thou.
Ian F
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Re: King pin shims.

Post by Ian F »

Good job!

Ian F
MGCC member
1972 BGT, Blaze, Navy trim, recessed grill
1961 Midget, 948cc, Clipper Blue, Blue trim and weather gear
Randy Forbes
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Re: King pin shims.

Post by Randy Forbes »

Maybe not such a necessity on an MGB, but the Healey (100, 100/6 & 3000) use an identical king-pin/stub-axle arrangement (of slightly increased size) and suppliers offer a "Nadella type" needle-roller bearing substitute for the bronze thrust washer.

Clearances are set as you would for the bronze thrust washer.

While it's nothing like adding real power steering, there was a noticeable reduction in steering effort.

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