Ceramic IMS Bearing failure
 

Although the topic of IMS bearings has been well covered over many years, I thought it might be worth sharing my experiences of a failing LN ceramic bearing in a 2001 Boxster. In this case, an LN Engineering dual row retrofit had been installed in the car in 2011 by a previous owner at around 80,000kms (50k miles).

An oil and filter change at around 140,000km (88k miles) – 6 years after installation – revealed ferrous debris in the filter. I put the car on stands and removed the transmission and flywheel – assuming that somehow the ‘new’ bearing had failed.

On removing the IMS flange, I found slight play in the bearing, but that it was intact.

On removal of the bearing, I found that apart from the slight play and a ‘rough’ feel, the bearing was otherwise in reasonable shape. On closer inspection however, it was apparent that one of the 18 ceramic balls was heavily pitted across most of its surface, with fissures where it seems the surface layer of the ball had flaked away. None of the other 17 balls in the double-row bearing were damaged. However, the inner and outer steel races contacted by the pitted ball had been worn away to some extent, causing debris in the oil filter.

It seems that this damage was the result of a random manufacturing defect limited to just one particular ceramic ball.

Some observations:

• Being a LN bearing, the outer seal was not fitted. The bearing had a lot of oil in it upon removal and it would seem that lack of lubrication was not a factor.
• The absence of the outer seal would presumably have allowed oil to quickly wash debris out of the bearing, probably limiting damage to the other other bearing row.
• As a dual row bearing, lack of much wear to the other (unaffected) row meant that the bearing would have continued to operate reasonably well for some time before failing completely.
• The washing out of particles as soon as wear began to occur would have meant that visible evidence of debris in the filter (and caught on a magnetic sump plug, had there been one) was obvious at an early stage (ie, potentially much earlier than if both seals were present).
• On the same lines, early washing out of metal particles may have meant those particles were larger and more likely to be captured by the oil filter than if they were trapped in the bearing and ground up into a fine abrasive paste.
• The absence of any other wear to the bearing suggests that without this one faulty ceramic ball, the bearing might otherwise have lasted the life of the car.
• Although popular advice suggests that once a bearing starts to disintegrate it’s too late to save the engine without a full teardown, that’s not my experience here. An engine oil flush and filter change and the engine appears to be as good as ever. However, this may not be the case where the original bearing is disintegrating with its seals intact – in that case, by the time there are large enough particles to be seen in the filter, there may be many more finely ground ones that may have slipped through and are circulating freely. This suggests to me that removing the outer seal of an original bearing is a minimum maintenance requirement.
• Ceramic ball bearings are still subject to unpredictable wear. Given LNE advise to replace their retrofit bearings at 75k miles or 6 years, using a standard steel bearing (I replaced the LN ceramic bearing with an off-the-shelf SKF 3204 bearing) and replacing them at the same frequency is probably just as good.

The photo is my attempt to show the one failed ceramic ball - the pits on the surface of the ball can be seen here (I haven't disassembled the bearing as it's now the paperweight on my office desk!)
Cheers
David
http://986forum.com/forums/uploads02...1515724899.jpg

Good read. I have nothing to add but I'm sure others will chime in.

See if Charles would like it back for examination.

Any idea why the bearing was changed in the first place?

When you fitted the new SKF 3204 , is it with or without the seals either side ?

Interesting stuff
 

Also interesting how economical those are, and most likely still far superior to the OEM bearing

OEM dual row bearing has a tiny failure rate.

If the only 'damage' to the bearing was pitting, where is the ferrous metal coming from? As it is, it looks like something else is wearing.

2 IMS bearings failed? Perhaps the cause is elsewhere. Shaft runout?

The metal debris was entirely from abrasion from the pitted ball - i.e. Steel races are softer than ceramic!
The original replacement was precautionary only I gather. So the only bearing to have failed was the LN one.
I can't see run out or lubrication or anything causing the failure here instead of one faulty ceramic ball.
Cheers
David

Sent from my F1f using Tapatalk

I fitted the 3204 bearing without the outside seal, by the way.

Sent from my F1f using Tapatalk

This is why.....
 

...it's worth the effort to invest in the "IMS Solution". No ball bearings to fail.

:cheers:

I’m planning to replace my LN IMS ‘Classic’ single row ceramic with the LN ‘IMS Solution’ this fall simply to put this issue to rest. My 550 SE is in excellent condition (knock on wood) and is shaping up as a long term keeper so it’s worth the investment to me.

Reading through an article on IMS bearing replacement on the PCA website Technical Area, one person wrote about the use of a cylindrical bearing vs the ball bearing replacement. He mentioned one product in particular called the European Parts Solution IMS Bearing Upgrade Kit. Has anyone heard anything about this product as a viable option? The cylindrical bearing format appears to provide greater inner bearing surface area. I believe this manufacturer also offers a direct oil feed version.

Here we go again . . . . . . . .
 

Arrgghhhhh!!!!

Wonder what kind of oil you guys recommend with this set up
... :p

Roller bearings do not provide any greater load carrying capabilities than ball bearings.

Thanks JFP. I appreciate your experience and feedback on this subject. Trying to weigh any options to make the proper decision when replacing mine later this year.

Generic 20w50 with Slick50 treatment ;) :eek: :D . . .not. . .

If you want to do it right, once and done forever, go with the IMS Solution.

Indeed....
 

....how do people NOT understand. A plain bearing floating on oil, versus a ball bearing or roller bearing with a bunch of moving parts that can fail?

Occam's razor.