Dave 2000
Not all Land Rovers are useless!
OK following up on https://forum.ih8mud.com/80-series-tech/365673-my-lc-80-thread.html I decided to go for the big end bearing replacement.
It was a straightforward affair apart from my torque wrench deciding it would fail just as the shops closed on Friday and with little hope of getting one before Monday, fortunately I was loaned one from a local garage, I will not go into the 'how to replace the bearings' ect because there are some already very good write ups on the topic here on mud.
OK to my observations, I know there has been lots of theories banded around about what causes these bearing problems everything from wrong oil to wrong bearing material ect, I would just like to add the following thoery.....SWARF!! I have looked at many threads with pictures on this and other forums as to why the bearings fail and it seems there is a pattern developing.
Obviously a lot of the japanese engine plants will have been automated and let us suppose that the method or process of cleaning the block or crank oilways after machining was flawed? It is interesting to note that more often than not bearings that were replaced earler rather than later (like mine) were found to have damage particularly on number 4 or 5 cylinders. Engines found with damage on other numbers pretty much all included number 4/5 cylinders. cases where for example cylinders number 1 was damaged and no other is very rare. Being an automated process the cleaning ect would have been repeated over and over perhaps repeating the error of not cleaning a particular oilway correctly?
If a small amount of swarf was pushed into the shell bearing at the start up stage the tolerances would have been very small indeed, on a new engine the small particle of swarf could perhaps gets embedded in the shell bearing only to start to move about and weaken the shell material later on in the engines life?
Just for a moment let us assume that is the case, the bearing starts to break up and small particles start to circulate around the engine and of course they get caught up in the oil filter, let us now assume the engine is not one that is regularly serviced and the oil filter starts to get clogged not just bearing material but other contaminants as well, once this happens the oil relief valve opens dumping unfiltered oil into the engine, opening this valve lowers the already relatively low oil pressure and recirculates contaminated oil, this is oil that also has bearing fragments in it, the lower oil pressure just adding to the problem. and then we see later on that many if not all the bearings are damaged.
I have only to offer my pics as perhaps evidence of this, my car has a FSH and it appears the engine has not been opened up at any time in it's pampered 16 year life, again looking at the pictures number 4 again rears it's ugly head with the other bearings in very good condition. Number 1 shows some very minor marking and the others show acceptable (if any) wear at 184,000 miles.
There was a theory that this damage was restricted to JDM cars i.e. the oil used in Japan by the PO/garages at service time, well that idea can gho straight out of the window with my UK registered version. The early services were by Toyota and as the car aged the servicing was taken over by another (non Toyota) garage, fortunately the garage was good at maintaining the service history and the printouts came with the car, they clearly show it was not neglected from a service/repair point of view and yet my vehicle was suffering the same fate as JDM imports.
Picture 1 is of the bearings removed from my car yesterday, 1 - 6 left to right, upper row are the rod shell bearings and the lower row their opposite, apart from some colour changing I was hard pressed to tell new from old in particular the non thrusted side or cap bearings, if the bearings were constructed of a problamatic material why is there no evidence of the others breaking up?
Just for the record I would add that changing the bearings has made no visible difference to my oil pressure readings and there was no visible damage to the crankshaft..
Just my 2 euros (inflation)
regards
Dave
It was a straightforward affair apart from my torque wrench deciding it would fail just as the shops closed on Friday and with little hope of getting one before Monday, fortunately I was loaned one from a local garage, I will not go into the 'how to replace the bearings' ect because there are some already very good write ups on the topic here on mud.
OK to my observations, I know there has been lots of theories banded around about what causes these bearing problems everything from wrong oil to wrong bearing material ect, I would just like to add the following thoery.....SWARF!! I have looked at many threads with pictures on this and other forums as to why the bearings fail and it seems there is a pattern developing.
Obviously a lot of the japanese engine plants will have been automated and let us suppose that the method or process of cleaning the block or crank oilways after machining was flawed? It is interesting to note that more often than not bearings that were replaced earler rather than later (like mine) were found to have damage particularly on number 4 or 5 cylinders. Engines found with damage on other numbers pretty much all included number 4/5 cylinders. cases where for example cylinders number 1 was damaged and no other is very rare. Being an automated process the cleaning ect would have been repeated over and over perhaps repeating the error of not cleaning a particular oilway correctly?
If a small amount of swarf was pushed into the shell bearing at the start up stage the tolerances would have been very small indeed, on a new engine the small particle of swarf could perhaps gets embedded in the shell bearing only to start to move about and weaken the shell material later on in the engines life?
Just for a moment let us assume that is the case, the bearing starts to break up and small particles start to circulate around the engine and of course they get caught up in the oil filter, let us now assume the engine is not one that is regularly serviced and the oil filter starts to get clogged not just bearing material but other contaminants as well, once this happens the oil relief valve opens dumping unfiltered oil into the engine, opening this valve lowers the already relatively low oil pressure and recirculates contaminated oil, this is oil that also has bearing fragments in it, the lower oil pressure just adding to the problem. and then we see later on that many if not all the bearings are damaged.
I have only to offer my pics as perhaps evidence of this, my car has a FSH and it appears the engine has not been opened up at any time in it's pampered 16 year life, again looking at the pictures number 4 again rears it's ugly head with the other bearings in very good condition. Number 1 shows some very minor marking and the others show acceptable (if any) wear at 184,000 miles.
There was a theory that this damage was restricted to JDM cars i.e. the oil used in Japan by the PO/garages at service time, well that idea can gho straight out of the window with my UK registered version. The early services were by Toyota and as the car aged the servicing was taken over by another (non Toyota) garage, fortunately the garage was good at maintaining the service history and the printouts came with the car, they clearly show it was not neglected from a service/repair point of view and yet my vehicle was suffering the same fate as JDM imports.
Picture 1 is of the bearings removed from my car yesterday, 1 - 6 left to right, upper row are the rod shell bearings and the lower row their opposite, apart from some colour changing I was hard pressed to tell new from old in particular the non thrusted side or cap bearings, if the bearings were constructed of a problamatic material why is there no evidence of the others breaking up?
Just for the record I would add that changing the bearings has made no visible difference to my oil pressure readings and there was no visible damage to the crankshaft..
Just my 2 euros (inflation)
regards
Dave
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