Hello all,
Just got myself an '04 40th Anniversary Porsche with about 49k miles on it. When i took it for PPI, the mechanic recommended (unsurprisingly) replacing the RMS and then simply removing the IMS bearing seal.
I asked him about the LNE IMS retrofit and he said that it was likely not that necessary, but also an option. I looked for more comparisons about the efficacy of each fix, but haven't found that much. He said he'd never seen one of the porches where he removed the bearing seal come back.
What do you guys think? I'm not averse to paying for the retrofit, but my dad (who knows alot about bearings) said that the seal removal might actually be more effective.
Sorry if there's another post analyzing this.
Thanks!

 

I just bought a 40th Anniversary #946 35k miles myself and I had the RMS and LN IMS replaced before taking delivery.

 

If you look at the LN Engineering site you will see an extensive write-up on the bearings. One of the things that they recommend if you are not replacing the bearing is to remove the outer seal to inspect the bearing, and to leave it off to allow oil to reach the bearing.

When I had my engine and trans out (several times actually) to fix the intermix I had the LN bearing tools was not yet perfected/available and I was not sure if the intermix was fixable so I did not want to spend the money and deal with the problems in removing the bearing. I did remove the seal and inspect the bearing, which appeared in good shape. I did leave the seal off. Now the bearing is not totally dependent on the original lubrication, but is bathed in engine oil. Of course the trick here is to keep fresh oil in the engine, no 10,000 mile changes, which I don't believe in anyway. I also installed the updated OEM flange which has better seals on it.

I have spoken to Charles at LN a couple of times since I did this as I am still contemplating dropping the trans just to put in the bearing replacement ( have a new clutch/flywheel with only about 7,000 mile on it). He actually said he was not necessarily recommending doing the replacement, but did say to keep an eye on the oil/magnetic drain plug to watch for any signs of metal particles that could be from the bearing starting to go. However with the low mileage I put on the car I really only change the oil once per year so I am thinking of going ahead with the bearing replacement just to sleep better at night.

Personally, if I had the trans out and the flywheel off to remove the seal and inspect the bearing I would go ahead and spend the $600-$700 to install the new bearing. I believe it is far superior to the OEM bearing, and the larger bolt and better flange are also an improvement. IMHO

 

i don't know about stats but my shop in town is the LN bearing dealer.

when doing RMS or a clutch job they check for play, if there's no play they just remove the seal; which was the case for me. They recommend getting the full LN bearing done on my next clutch job as part of maintenence i have 96000kms on the clock.

i've read alot of guys getting the LN bearing done and their original bearing was still perfect and rock solid. the cases are rare, and tragic when they happen, but I think it's not very common. I've heard loosely "a 1 in 2000 chance" from porsche specialists.

but as for just removing the seal, I had the chance to put the LN bearing in and didn't for no other reason than my shop said there's NO PLAY and if it ain't broke don't fix it.... i think removing the seal is a fantastic solution and I can tell you I sleep better at night having that done.

 

Thanks for the advice guys. I'll take it to a shop in my area. I need to get the RMS replaced anyway so the bearing should just be a $6-700 extra charge. I'll think of it as an insurance policy on my new (old) car. There's no point in risking a 16k engine job.
What are the other parts likely to fail on this bad boy?