986 Forum - The Community for Porsche Boxster & Cayman Owners - View Single Post - IMS

Smallblock454 · 07-25-2017, 09:00 AM

Hi,

i'd like to summarize some things.

The IMSB specs are important. Especially the technical specs of the bearing itself. Same size and type doesn't mean same technical specs.

If you remove a seal from a sealed IMSB you just have no specs, because the bearing wasn't designed and tested for that by the manufacturer.

If you have a damaged IMSB, you need to do much more than just to replace it and the risk that your engine might fail is very very high.

The lung effect (as Silber called it) is for shure problem. And no tiny IMSB seal will handle that. So there were many attempts to solve the problem. DOF and open bearings and so on. In the end the plain bearing might be a solution, but at a price point where i just say no, because there are also other engine parts that can fail, so no win.

The IMSB is one thing, but the other more important thing (compared to a better spec IMSB than the OEM one) is the proper deinstallation of the IMSB and parts related, so the IMS doesn't get damage in any way and also the proper installation of the new IMSB and all the parts related. I think that topic is often underrated, but it's very easy to harm an IMSB or IMS when you install or deinstall.

My personal conclusion: i have a manual transmission. I need a new clutch around every 100 K Km (approx 66 K miles). I do an IMSB change every time i do the clutch. I do a yearly oil change, even if i drive much less than 5 K Km (3 K miles) a year. And if the engine or ISMB fails, it fails.

Regards, Markus

PS: SIlber: i think you have the right approach, but i wouldn't insist on looking for a "lifetime" solution.

07-25-2017, 09:00 AM	#53
Smallblock454 Registered User Join Date: Jun 2014 Location: LB, Germany Posts: 1,456	Hi, i'd like to summarize some things. The IMSB specs are important. Especially the technical specs of the bearing itself. Same size and type doesn't mean same technical specs. If you remove a seal from a sealed IMSB you just have no specs, because the bearing wasn't designed and tested for that by the manufacturer. If you have a damaged IMSB, you need to do much more than just to replace it and the risk that your engine might fail is very very high. The lung effect (as Silber called it) is for shure problem. And no tiny IMSB seal will handle that. So there were many attempts to solve the problem. DOF and open bearings and so on. In the end the plain bearing might be a solution, but at a price point where i just say no, because there are also other engine parts that can fail, so no win. The IMSB is one thing, but the other more important thing (compared to a better spec IMSB than the OEM one) is the proper deinstallation of the IMSB and parts related, so the IMS doesn't get damage in any way and also the proper installation of the new IMSB and all the parts related. I think that topic is often underrated, but it's very easy to harm an IMSB or IMS when you install or deinstall. My personal conclusion: i have a manual transmission. I need a new clutch around every 100 K Km (approx 66 K miles). I do an IMSB change every time i do the clutch. I do a yearly oil change, even if i drive much less than 5 K Km (3 K miles) a year. And if the engine or ISMB fails, it fails. Regards, Markus PS: SIlber: i think you have the right approach, but i wouldn't insist on looking for a "lifetime" solution.