Robin 993DX

Nick,

I talk to a lot of people all the time about our Porsches so I apologize your name doesn't ring a bell right now. But I could be having a senior moment.

Most everyone knows me on the 993 board, due to all the DIY projects on the 993s I posted on my web site http://p-car.com which are the same DIYs listed on Pelicanparts.com Chris Walrod and I work on bigger 993s projects often on weekends, more for fun than anything else as we both have regular day jobs. We have no intention of opening a shop, just want to keep things on a fun level.

I haven't had the need to create the same DIY site for the 996 because there isn't much you need to do with these cars.

I lived in Atlanta for 7 years and then 2 years in Miami, moved back to Southern California in 2004, not sure if I am the same Robin you were referring to.

Palmbeacher

Note that I am not disputing the wisdom of replacing it (I would have done likewise) but aside from it being devoid of grease (presumably it had been lubricated by oil splash, just as the new LN bearing will be) what do you base your conclusion that it was going to give out? Was there slop in the bolt shaft, play in the bearing itself, pitting of the *****, damage to the ball separator, etc.? An article in Total 911 states the opinion of some Brit authorities that if the bearing survives long enough for the seal to give way so the bearing gets freely lubricated from cam chain oil splash, it will likely last the life of the engine. I'm just curious what physical condition your IMS bearing was in after 100K.

450knotOffice

The Pinion bearing in my daily driver 996 is also on the way out. It's been whining for some time. I have a friend who can do all of that stuff - other than pressing the bearings off and onto the tapered shaft. I understand that a really high load press is needed for that job. How were you guys able to get that done? I'm curious because I may ask for your help with this job, at least in that area.

Great job and thanks for the writeup and pictures!

C4CRNA

Thank You, Thank You, Great Pictures,WOW!

Robin 993DX

There are two problems with the splash lubrication theory.

(1). There isn't enough splash, I noticed the oil that came out were dirtier than the rest of the oil, which tells me that there isn't enough circulation in that area

(2). The seal cover prevents enough of the splash to get into the bearings to keeps them properly lubricated.

I will be sending my bearings out for testing and to see exactly what condition they were in.

Robin 993DX

The hardest part was to press the gears and bearing off, which required a very high tonnage press. In addition you will need to fabricate plates of various size to grab on to each of the gears while they are pressed out.

You should contact Chris Walrod for details, as he did all the pressing and fitting.

Thanks

fast996

great write up!! thank u

thirteeneast

Many thanks for sharing, great pictures too.

Can we have that sticky somewhere so my dumb head cant lose it?.

Palmbeacher

So basically what you're saying is that LN Engineering, who designed and sells the retrofit bearing which depends entirely on splash lubrication, is wrong on their basic premise. So why then did you put in a bearing requiring splash lubrication rather than re-pack the original one with grease and put in a new seal?

Robin 993DX

Because the bearings used by LN's will last 3 times longer even with moderate splash lubrication.

They even say that on their web site:
"ur kits replace the factory sealed bearing with a new, severe duty custom ceramic hybrid roller ball bearing for reduced friction and superior performance in poorly lubricated operating conditions and replaces the factory IMS flange hub, bearing support, and fastener with a stronger, revised billet chromoly assembly."

chris walrod

This is the main issue with sealed bearing in the engine and gbx, the grease slings out presumably from centrifugal forces / heat and oil cannot get back into the bearings to offer proper lubrication.

If you pull the drain plug on the trans, you can reach up there with your pinky (sounds nice, doesnt it) and feel for excessive lumps of grease on the magnet located about an inch from the drain plug port. If you feel the grease, its come from the pinion and or layshaft bearings. Just a matter of time at that point

Eharrison

Very nice guys I appreciate the photos and skill! Good job!

Palmbeacher

Makes perfect sense to me. One of the things I questioned about the concept of merely removing the seal (as advocated by a UK-based authority) was that the placement of the bearing was not designed for oil lubrication, not to mention that the OEM bearing internal clearances are designed for a much thicker lubricant (grease) and unless there were copious amounts of oil circulating under significant pressure, I would not expect optimal lubrication. That said, most of the OEM bearings seem to last a long time, and it's only a tiny (albeit unknown) percentage that self-destruct prematurely.

Robin 993DX

I am not much of a gambler, can't even land 2 matching number on lotto tickets. I rather not take the chance, so I replaced it.

chris walrod

One interesting aspect I found in this gbx is that the pinion bearing was made in Brazil, but the Genuine Porsche replacement bearing was made in Germany --I'd been advised to use only German-made bearings.