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BEB done
- Thread starter LC80tim
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- May 26, 2014
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Ive had the milners bearings you mention in for over 100000 miles. Ive not checked there condition, but there's no rattles and the conrod is still conected to the crank shaft.
Cue catastrophic failure first thing tomorrow morning. ..
Cue catastrophic failure first thing tomorrow morning. ..
Gary820
Well-Known Member
Just Google mini crankshaft bearing.
Yep manufacturers get it wrong still lol.
We have cars sat waiting for new engines! Having issues with the 3 cylinder engines currently!
Looks like caught those in time. I imagine a lot of people have had failures and never heard of the problems
Yep manufacturers get it wrong still lol.
We have cars sat waiting for new engines! Having issues with the 3 cylinder engines currently!
Looks like caught those in time. I imagine a lot of people have had failures and never heard of the problems
Look similar if not a little worse than mine when I changed them, IIRC mine were circa 185,000 miles?
I have heard a dozen theories about what causes it and have yet to see a conclusion. I am not happy with the oil reason, only because mine was serviced regularly from new and it would not have had the Japanese oil in there for long. What I do plan to do at 100,000 miles I will pull the pan and check them, I have ACL's in there ATM.
I am in the camp of bearing manufacturing fault, it is the only constant IMO, a few hundred thousand with poor bonding of the indium to the shell backing?
When this was being discussed on 'MUD', I threw into the mix another thought, and it was only that with no evidence to back it up.
What if it is an issue with the way these engines are timed. The damage always seems to be worse on the rod bearing (combustion thrust) as opposed to the cap bearing, i.e if the timing was just a tad to far advanced, over time the bearing surface starts to break up the resulting particles get embedded in the cap side of the shell.
Another thought I had was a problem with the process used to clean swarf from the crankshaft, I noted a lot of being pictures showed more damage at number 4 cylinder, I was thinking perhaps that was a little coincidental, but machine swarf could be getting trapped although I would have thought there would be more to scoring of the shell rather than delaminating.
I have read enough to know that the engine will ultimately 'put a leg out of bed' when the rod fails.
regards
Dave
I have heard a dozen theories about what causes it and have yet to see a conclusion. I am not happy with the oil reason, only because mine was serviced regularly from new and it would not have had the Japanese oil in there for long. What I do plan to do at 100,000 miles I will pull the pan and check them, I have ACL's in there ATM.
I am in the camp of bearing manufacturing fault, it is the only constant IMO, a few hundred thousand with poor bonding of the indium to the shell backing?
When this was being discussed on 'MUD', I threw into the mix another thought, and it was only that with no evidence to back it up.
What if it is an issue with the way these engines are timed. The damage always seems to be worse on the rod bearing (combustion thrust) as opposed to the cap bearing, i.e if the timing was just a tad to far advanced, over time the bearing surface starts to break up the resulting particles get embedded in the cap side of the shell.
Another thought I had was a problem with the process used to clean swarf from the crankshaft, I noted a lot of being pictures showed more damage at number 4 cylinder, I was thinking perhaps that was a little coincidental, but machine swarf could be getting trapped although I would have thought there would be more to scoring of the shell rather than delaminating.
I have read enough to know that the engine will ultimately 'put a leg out of bed' when the rod fails.
regards
Dave
Apart from damage due to trapped contaminates, the "cap" shell has no forces on it whatsoever, the cap is only there to keep the con rod attached to the crank.
Compression force and drive force after ignition are both on the "rod" shell, leaving the "cap" shell with no force at all other than carrying the journal end of the con rod around circa 180 degrees to the next loading on the "rod" shell.
Compression force and drive force after ignition are both on the "rod" shell, leaving the "cap" shell with no force at all other than carrying the journal end of the con rod around circa 180 degrees to the next loading on the "rod" shell.
Have to disagree with that Clive. Whilst I agree the rod takes most of the forces applied, the cap and bolts have to take the load of stopping a piston going through the head, and reversing it's direction (exhaust stroke for example) and with a rotational force of circa 4,500 rpm (our diesels), must place considerable strain on them?
I remember years back with high revving 'crossflow' engines, when reconditioning we often had to have the con rods machined to get the correct bearing crush, the 'hole' having been elongated by a thou or two.
regards
Dave
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Of course my comment should have said "relatively" no load.
Point taken, but I'd imagine if you did the calculations, the force applied on the "cap" bearing stopping a piston on the exhaust stroke wouldn't be comparable with the compression stroke or firing stroke forces.
JMO, and I'm not able to support it with any attempt at the calcs.
