Buying used Boxster S - IMS flange replaced but not IMS bearing?

[Jake Raby]

Originally Posted by sranton

Thanks for the help guys. Sounds like I can rest a bit easier knowing it has the dual row IMSB! (Please, correct me if I'm wrong here) I will still plan to install an upgrade kit once it is time for a new clutch, but that won't be for a while since it was done recently.

And thanks Dennis for the clarification on interpreting the PET. Much clearer now!

The problem with the dual row bearing is it takes too long to fail... The bearing has twice as many components to share radial and longitudinal loads, so symptoms of failure are non- existent for a long period of time. That means that the dual row bearing can be filling the oil system with ferro- magnetic debris that the oil filter will byass into the primary oil system and feed to the main and rod bearings, along with every other internally lubricated component within the engine.

We see more widespread collateral damage from dual row bearing engines than all others combined due to this characteristic. The longer an engine runs with contaminated oil, the lesser the chances are of ever resurrecting the engine once IMSB failure symptoms do present themselves.

Single row engines skip stage 3 bearing failure altogether and just break, which can be a good thing for the rest of the engine.

[j.fro]

[QUOTE=Jake Raby;412459]The problem with the dual row bearing is it takes too long to fail...
LMFAO
Freudian slip coming from the Jake??
In all seriousness, Jake's bearing is an honest product and a great solution to a disastrous manufacturer defect. I'm running one in my 996. Sranton, I think you're on the right track.

[Jake Raby]

[QUOTE=j.fro;412482]

Originally Posted by Jake Raby

The problem with the dual row bearing is it takes too long to fail...
LMFAO
Freudian slip coming from the Jake??
In all seriousness, Jake's bearing is an honest product and a great solution to a disastrous manufacturer defect. I'm running one in my 996. Sranton, I think you're on the right track.

No, The dual row bearing remains at stage 3 failure far too long.. Trust that doesn't mean that I am saying that it takes too long to begin failing, because I am not saying that.

Once the bearing starts to fail it emits debris for way too long.. The bearing has already failed, it just allows the engine to run too long as all the processes take longer to progress into complete engine failure.

Last week we pulled apart a core that had a failing dual row IMSB. The bearing was still together and had not reached stage 4 failure yet. The crankshaft, every cam journal, and all the cylinders, the main oil pump and scavenge oil pumps were all wasted.

It was a classic example of a dual row bearing dying a slow, symptomless death and creating engine wide collateral damage of disastrous proportions.

[epapp]

Originally Posted by Jake Raby

No, The dual row bearing remains at stage 3 failure far too long.. Trust that doesn't mean that I am saying that it takes too long to begin failing, because I am not saying that.

Once the bearing starts to fail it emits debris for way too long.. The bearing has already failed, it just allows the engine to run too long as all the processes take longer to progress into complete engine failure.

Last week we pulled apart a core that had a failing dual row IMSB. The bearing was still together and had not reached stage 4 failure yet. The crankshaft, every cam journal, and all the cylinders, the main oil pump and scavenge oil pumps were all wasted.

It was a classic example of a dual row bearing dying a slow, symptomless death and creating engine wide collateral damage of disastrous proportions.

I wouldn't say completely symptomless. Thats where blackstone comes in.