DennisAN

I'm starting to look for a Boxster, and from my reading I'm mostly considering ones from the model years 2000 through 2002. Partly this is because model year 2002 was the last year of the 5 chain cam drives, which appears less easy for the home mechanic to screw up while servicing than the later 3 chain cam drives.

Statistics from the IMS class action suit say that the 2-row IMS bearings have about a 1% failure rate and the 1-row bearings have more like a 10% failure rate. The Pelican fix entails replacing the OEM bearing with an improved 1-row bearing. This makes sense for the 1-row cars, but does it really make sense to replace a less-troublesome OEM 2-row bearing with an aftermarket 1-row bearing?

Would it make more sense to replace a 2-row bearing with another OEM style (SKF, Timken et al.), and maybe replace the center bolt with the Pelican improved bolt? Does their improved bolt even fit an OEM 2-row bearing?

I'm retired with a large 3 car garage and a big toolbox, so I'm actually looking for another "project" car. Downtime isn't a problem with two other cars already.

Macster

Too much to digest and offer a slimmed down version, so you are on your own.

But here is the link to a thread that I think contains answers to your questions:

http://forums.pelicanparts.com/boxst...placement.html

Added: Here's a link to an article that covers what you are talking about in much more detail:

http://www.pelicanparts.com/techarti...ft_Bearing.htm

DennisAN

Thanks, but I've bought Wayne's book and have been working my way through it already. The thread you posted is over a year old and IIUC the statistics on IMS bearing failure for 2-row vs. 1-row appear to have been collected for the Eisen v. Porsche lawsuit from 2013. The thread did not discuss my thoughts that lower-failure-rate 2-row bearings may be better off left alone or replaced with another OEM style 2-row bearing. Maybe I should just go ask Wayne.

Flat6 Innovations

Two rows are always better than one. Twice the load carrying capacity and twice as much thrust control in the longitudinal axis.

Extracting a dual row and replacing it with a single makes zero sense to me.

Macster

Asking Wayne I believe would be a good idea. It would be interesting to read what he has to say if you can share it.

mikefocke

Given the failure rate of single row bearings, why in the world would you ever think of replacing a bearing with a single row if you had a double row? The way to go would be just the opposite, single replaced by double but that isn't possible.

If you have a double row (and maybe you do and maybe you don't and you won't know until you can look at the back of the engine with the transmission off) just get the LN double row kit whose failure rate is very very favorable (like darn close to zero) and that failure rate is based on the largest sample of installed kits of any kit available... and let an experienced installer take your worries away.

There isn't another kit with the number of installs the LNs have.

Flat6 Innovations

Currently dual row LN failures are ZERO.

Dave H.

since my dual row LN bearing went in 2 years ago, i don't even think about it anymore