Quote:
Originally Posted by Nine8Six
Its "ICCL" (I couldn't care less)
Do this for fun mate: Run a shaft at 5,000rpm with 'only' 0.1mm run-out, now put a few chains on it to create even more noise, and run it in this condition for let's say 10hrs. Come back to let us know how your bearing seal look like after that.
In fact if it last 2hrs I'd be surprised.
Said 5,000rpm. Not idle at 1,100rpm
Try!!!
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One of the contributory factors to IMSB failure is gentle driving - so say the experts.(not me ) So the rev/endurance test seems spurious .The bearings that do survive are generally the -- ones "driven like the Dr. intended" !
Jake has cited IMS run out as a cause of failure for some IMSB's on several forums and at some length in the past. He discovered this while repeatedly testing engines with a history of destroying IMSB's while developing The Solution - a lubricated plain bearing with I 'seal'. Up to that point, nobody had mentioned the run out idea.
Jake & JFP hint that the misalignment issue is not as frequent a cause of IMSB failure as seal deterioration and other causes IIRC. And those two guys have seen a lot of failed IMSB's (unlike you- none or I- I have 2 -so far)!
But you claim run out is the major(or only ?) cause of IMSB failure .
IMSB failure is usually rectified by a replacement bearing with only 1 seal fitted.No correction of run out is measured, made or is possible. Often ,in the case of the double row, the replacement bearing is the same load specification as the original bearing fitted at the Factory.
So , wouldn't these replacement bearings also fail repeatedly because nothing has been done to correct the alignment(Jake's experience).? Answer - it depends how bad the run out is.
If the issue is simply bearings that lost their grease through deteriorated seals and failed, that explains why most upgrade replacement IMSB with *2041RS do not fail ? Some, but not all IMSB kits have upgraded bearings .All have only 1 seal. So, the single seal seems a major part of the solution to the IMSB failure problem.
I am all for a disruptive discovery to upend the IMSB failure story. But your case has no new data nor any field results and does not refute accepted theories from those who have lots of data,experience,credibility and 'skin in the game.' And as you concede ,you've never seen an IMS .
But I am certainly open to persuasion that run out is the main cause. I understand that any source of vibration would 'hammer' the bearing.It might explain the success of the roller bearing kits?
The take home is that an upgraded bearing with just 1 seal (*2041RS) seem to be a generally successful solution . The 'repeat offenders' in the IMSB problem are so few we seldom hear about them. But the cars with slightly (define !) out of round problems may benefit from a higher load capacity bearing - like The Solution.
I have not seen a "Pre- Qualification Test" for out of round in any IMSB kit. Anyone seen this?