Main Bearing Shell Replacement, 1098 engine

Discuss mechanical problems here.
Forum rules
By using this site, you agree to our rules. Please see: Terms of Use
Post Reply
Telpet
Minor Friendly
Posts: 34
Joined: Mon Oct 18, 2010 8:41 am
MMOC Member: No

Main Bearing Shell Replacement, 1098 engine

Post 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
bmcecosse
Minor Maniac
Posts: 46561
Joined: Wed Feb 16, 2005 11:24 pm
Location: ML9
MMOC Member: No

Re: Main Bearing Shell Replacement, 1098 engine

Post 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.
ImageImage
Image
Telpet
Minor Friendly
Posts: 34
Joined: Mon Oct 18, 2010 8:41 am
MMOC Member: No

Re: Main Bearing Shell Replacement, 1098 engine

Post 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.
izzi
Minor Fan
Posts: 105
Joined: Fri May 13, 2011 7:48 pm
MMOC Member: No

Re: Main Bearing Shell Replacement, 1098 engine

Post 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. :)
Telpet
Minor Friendly
Posts: 34
Joined: Mon Oct 18, 2010 8:41 am
MMOC Member: No

Re: Main Bearing Shell Replacement, 1098 engine

Post 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
bmcecosse
Minor Maniac
Posts: 46561
Joined: Wed Feb 16, 2005 11:24 pm
Location: ML9
MMOC Member: No

Re: Main Bearing Shell Replacement, 1098 engine

Post 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.
ImageImage
Image
JOWETTJAVELIN
Minor Legend
Posts: 2775
Joined: Mon Dec 12, 2011 7:20 pm
Location: LANCASHIRE (paradise)
MMOC Member: Yes

Re: Main Bearing Shell Replacement, 1098 engine

Post 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. :)
izzi
Minor Fan
Posts: 105
Joined: Fri May 13, 2011 7:48 pm
MMOC Member: No

Re: Main Bearing Shell Replacement, 1098 engine

Post 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. :)
Post Reply