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Ldb Mklll engine pivot bolt silent-block bushes

PostPosted: Wed May 10, 2023 6:23 pm
by rlpembridge
I have a new pair of engine pivot bolt silent-block bushes to fit into the crankcase lugs of my (currently stripped), engine. I notice the inner ring protrudes by 2mm on one side but is flush with the outer ring of the bush on the other side.
Anyone know which way round they should be fitted?

Whilst they must both be fitted with the protrusion facing either in or out, I can see pros & cons in either case.
My initial reasoning is that the protruding side of the bush should face inwards. In that way, the pivot bolt should lock only that inner ring of the bush against the split collets that are driven into the frame - but is that necessary?

I recall quite a bit of 'wiggling' was required to free and lift the engine out of the frame and my only concern on the above format is that, with the protrusions facing inward, that additional reduction of clearance between the two engine lugs may impede and make the refitting of the engine into the frame even tighter / too tight.

Clearly, prior measurements will address some questions here but any knowledge of the correct fitting format would be apreciated.

Incidentally, the reason I completely stripped my crankcase was to have the exhaust mounting-bolt lug re-built by a specialist aluminium castings welder.
Fingers will be crossed for that repair working.

Re: Ldb Mklll engine pivot bolt silent-block bushes

PostPosted: Sat May 13, 2023 5:20 am
by jbcollier
Download this pdf of the Instructions For Service Stations 150D/LD:

http://www.oldtimerworkshop.com/files/L ... _Shops.pdf

Go to page 78

The 2mm protrusions face out, flush inside.

Re: Ldb Mklll engine pivot bolt silent-block bushes

PostPosted: Wed May 17, 2023 9:47 pm
by rlpembridge
jbc, that's most helpful. Thank you. I have two ancient handbooks (Pitman's 'Book of the Lambretta' by R G Warring and a Serviceman's book by D B Palmer, published by Lambretta Concessionaires), but the detail and data in that pdf surpasses both for technical data.