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Big end/main Bearing trouble?

Posted: Mon Mar 03, 2008 9:12 pm
by mogatron
hello,
sadly the mogatron isn't very well. :cry: i think its got someting to do with big end bearing. there a loud knocking from engine when under pressure. Could someone let me know if this big job that could do at home or job for the pro's? also what best to takle problem?
Thanks

Posted: Mon Mar 03, 2008 9:27 pm
by bigginger
*IF* it's the big ends, it's DIYable, but you'll need to be confident - and have a torque wrench. It means taking out and then replacing the bearing shells, which I'm told is possible with the engine in the car - actually, now I remember, I've done it, so it is :D
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Posted: Mon Mar 03, 2008 10:21 pm
by dougie700
if there was only 1 thing great about moggy's it would be that 99% of the jobs are all "doable" as long as you are happy to spend hours, maybe even days with yer feet sticking out from underneath em and a copy of the haynes manual. Plus you have the added expertise of the people on this forum to bounce your problems off.

cos i do beleive that with all the owners on this forum, every moggy problem has been coverd at some time :)

Posted: Mon Mar 03, 2008 10:40 pm
by MoggyTech
Do you have an oil pressure gauge in the car? If not hook one up, and check the oil pressure. Slight drop signals big end bearing failure. Large drop signals main end bearing failure (Usually with vibration from the engine as well).

Big ends easy to do with engine in the car, engine out for main end though.

Posted: Mon Mar 03, 2008 11:59 pm
by mogatron
she's no oil pressure gauge fitted. i'll have to have a fiddle tomorrow and see. wen i find out which one needs changing how do i go about measuring the sizes of the shells needed? ulso do i change all of the shells?

Posted: Tue Mar 04, 2008 12:15 am
by bigginger
You'd be better doing the lot, certainly. The shells you remove should have the size (+10 etc) size marked on them, but I'm sure you can measure if they don't - reckon you'd need a micrometer though, and that's beyond my experience.
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Posted: Tue Mar 04, 2008 12:40 am
by MoggyTech
Yup shells should be marked for size, and replace the lot. If no sizes, you will need Vernier Calipers to measure the crank journals and check the readings against the BMC manual specs. If there are any signs of scuffing on the crank journals, they will need to be checked for ovality, again using vernier calipers.

Posted: Tue Mar 04, 2008 2:26 pm
by bmcecosse
If it's making a 'loud knocking' - then don't be deluded into thinking it's just a case of changing the big end shells. Almost certainly the crankshaft will be damaged and needing a regrind - so that's engine out - and service excahnge crankshaft (or have it reground locally) -and then refit. Wise to also fit a new oil pump and a timing chain while it's in bits.

Posted: Tue Mar 04, 2008 3:44 pm
by mogatron
ok so i've got the big end shells out and they are knackered. the crank journals are oveled by 0.022in at worst. i take it that it needs grinding. any idea how much it will cost to get it done locally or is best to get a recon one?

Posted: Tue Mar 04, 2008 3:53 pm
by bmcecosse
Are they oval by 22 thou - or just 20 thou undersize with 2 thou of additional wear/ovality ? Anyway - this should be the crank (1098 ??) from Bull Motif. http://www.morrisminorspares.net/shop_item.php?ID=1982 Also add oil pump + timing chain - and a bottom end gasket set.

Posted: Tue Mar 04, 2008 5:12 pm
by newagetraveller
Look up ENGINE RECONDITIONING in the Yellow Pages. Tell them that you want a Morris Minor crankshaft regrinding and ask for a quote. This should be as easy as falling off a log for most establishments. Usually they will also supply new bearing shells and any other parts that you need. Most operate a delivery service whereby a dolly bird in a van picks up your crankshaft and returns the reground item a few days later together with any other parts that you require.

Posted: Tue Mar 04, 2008 5:27 pm
by bigginger
A "dolly bird"?
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Posted: Tue Mar 04, 2008 5:34 pm
by MoggyTech
bigginger wrote:A "dolly bird"?
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I know. The parts delivery van around here is driven by a guy, with a face like a kicked in Swarfega tin :o

Posted: Tue Mar 04, 2008 5:51 pm
by bigginger
Just I thought it was 1966 again, and nobody had told me...
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Posted: Tue Mar 04, 2008 5:54 pm
by MoggyTech
bigginger wrote:Just I thought it was 1966 again, and nobody had told me...
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Hmmm that would be nice, I was 13 without a care in the World. :D

Posted: Tue Mar 04, 2008 6:09 pm
by bigginger
2, me - and ditto :D
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Posted: Tue Mar 04, 2008 6:53 pm
by bmcecosse
Crank regrind around here usually about £50/£60 plus bearings which are often sold without any discount at around £40 the set. So - the Bull Motif exchange crank looks like good value - especially if you can collect to save carriage and deposit. I'm sure other Minor suppliers will do a similar deal - so check out whoever is nearest to you.
Edit - I see ESM sell theirs for £75 - even better value! http://morrisminorspares.co.uk/shop/pop ... .php?pID=2

Posted: Tue Mar 04, 2008 7:10 pm
by MoggyTech
bigginger wrote:2, me - and ditto :D
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Ah your still just a young wipper snapper :D Everyone told me life begins at 40, I'm still waiting. :o

Posted: Tue Mar 04, 2008 7:29 pm
by bigginger
Same here...
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