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Main Bearing Shell Replacement, 1098 engine

Posted: Sat Sep 08, 2012 8:54 am
by Telpet
Is it possible to renew the main bearings shells without removing the engine, and if so are there any particular snags or pointers. Thank you,

Telpet

Re: Main Bearing Shell Replacement, 1098 engine

Posted: Sat Sep 08, 2012 9:47 am
by bmcecosse
Not really - you could do the centre one easily, and the front one by dismantling the timing gear and front plate - but the rear is not possible. In general - if the main shells are worn - the crank needs a re-grind, and a new oil pump is always a good idea when you do that.

Re: Main Bearing Shell Replacement, 1098 engine

Posted: Sun Sep 09, 2012 2:12 pm
by Telpet
Many thanks for your reply. I was in fact thinking of big end shells replacement but somehow managed, wrongly, to type in main bearing.

Re: Main Bearing Shell Replacement, 1098 engine

Posted: Sun Sep 09, 2012 4:43 pm
by izzi
Hi,
If you can remove the sump, you can replace big end shells,be careful when refitting sump seals and gasket.

Mind the oil drips,etc;

Roy. :)

Re: Main Bearing Shell Replacement, 1098 engine

Posted: Sun Sep 09, 2012 5:21 pm
by Telpet
Hi Roy,
Many thanks for your advice. I had the sump down a few months ago in order to renew gasket and seals. Looks as though I will be repeating this exercise,plus of course putting in new shells.

Telpet

Re: Main Bearing Shell Replacement, 1098 engine

Posted: Sun Sep 09, 2012 9:43 pm
by bmcecosse
It's worth a try - but if the crank is scored it's a waste of money. While in there inspect the centre main - if it's worn through or scored - crank regrind is the way forward.

Re: Main Bearing Shell Replacement, 1098 engine

Posted: Mon Sep 10, 2012 5:32 pm
by JOWETTJAVELIN
Trust me I know, like many others, swapping bearings is no good. Have the crank re-ground.

One of my big-ends is currently packed with shimstock and gear oil used to quieten things down (just like back in the day, remember?). Been knocking along for ages like this but is now slowly dying. Rebuilt 803 will be fitted before winter. :)

Re: Main Bearing Shell Replacement, 1098 engine

Posted: Mon Sep 10, 2012 9:39 pm
by izzi
HI,
If your crankshaft does need a regrind, then may parts will have worn. Then it may be cheaper in the long run to have a bottom end exchange engine.
lets hope your mains are fine.

Roy. :)