SWODOC

26: New 1981 924 Turbo (which I could ill afford). It had impressive turbo lag but otherwise was a fine, fun car.

Had it 2 years, found my wife with its assistance, got married, then sold it to buy a house in SoCal. Sold for a new '84 Nissan King Cab pick-up. Huh???

Later, had a 928 S4 and currently have a 2003 996 C2 Cabrio....

For logray: Thanks for taking the time to look into my replacement engine serial #. Like many others on this thread, I too am not losing sleep over the issue. This is my sunny day car (and there are typically plenty of those here in FL) and I usual run it pretty hard on the back roads....I'll just keep enjoying it!

I'm not so sure I agree about that "must" comment...

But if your engine has the larger 22mm bearing the engine must be torn down to retrofit (and according to LNE every 50,000 miles or so as it is being deemed a "service wear" item).

Perhaps the IMS Guardian is a better alternative.

As for whether or not yours has the bearing or not, 2005 engines are the first year those bearings started showing up, but some of that might depend on what month.

If you post your engines serial number perhaps it could be decoded and compared with another engine's sequence number that does have the revised Porsche bearing.

Aside from the above, the only certain way to determine bearing type is to remove the transmission and flywheel to inspect the IMS flange and center nut.

In response to the above, here's my replacement engine's serial #: 03AT66566755

If anyone can determine if this has the 13mm or 22mm nut I'd be HUGELY appreciative.

Thanks!

First post to this most excellent forum! Previously owned '81 924 Turbo (bought new when I was young & single!), and '89 928 S4 bought 1993 and sold in 1997. So I've been without for many years until my recent purchase of a '03 996 C2 cabrio (which required significant negotiations with the wife as we have 3 in college now!). I've had it now for about a year and am most assuredly a 911 devotee! I'm the 3rd owner; the 2nd owner bought it as a CPO and blew the engine, which was replaced by the Porsche dealer with a 2005 engine in April 2007. There is now approx 12,500 miles on the '05 engine. I've been reading about the LN IMS retrofit kits also, but does anyone know how I can tell if my current '05 engine has the 13mm or 22mm IMS bearing nut, as the way I understand things the 22mm size can't use the LN retrofit?? As an aside, the latest (Dec 2011) edition of Panorama Tech Q&A section discusses 996 IMS bearings with Mr. Reiser stating "the LN Bearing Retrofit kit is a must on all 996 models".

Thanks for any assistance & advice!