IMS LN replacement update

so i was asked to post info from you guys as of milage ect on my car well here it goes my ims bearing was perfectly fine, my car has 100,800 miles. its a 1999 c2 6 speed. the rear main was fine too. the bearing didnt moan, no metal shavings and no play in the shaft and the seal looked good. heres a picture. IMG_20101102_205245.jpg

Looks like mine 1999 c2, 55K miles.... Maybe owning the 99 ain't so bad!

thats not the first time i have heard this about 99's... Rennlist Memeber "DeadEye" on here is a local friend of mine with a 99 C2 and he as well has never had a RMS/IMS Issues...

That looks like a Japanese made bearing... The dual row bearings can be made in any of 4 different countries :-) Remove that bearing's outer seal and see if the internals are filled with grease or oil.. If the bearing has oil inside it, instead of grease the bearing has already extended to a stage 1 failure. The stage 1 is a failure of the outer seal allowing oil to enter the bearing and wash the permanent lubrication away. This is what starts the downhill spiral that can advance to a point of serious failure extremely quickly. How much oil was released from the IMS tube when the bearing was extracted?

Quotes source post: 8026418

I have a question regarding this. Since the bearing is held into place by the flange that has a seal on the outer flange-to-engine block mating, to stop oil from pushing into the bell housing. There are no seals between the shaft and the IMS bearing, which permits oil to seep into the IMS itself from between the inner ring (of the bearing) and flange shaft. Although a compromise on both bearing seals would increase the oil seeping into the IMS, it's not the only way that oil can seep in. Is this a correct assumption? How would a comprimised bearing increase the capacity of oil within the shaft. I would assume that it would have a decreased capacity since the opening would be larger. A bearing with no seals is not a one way valve.

Idk, since I didn't do the work

Quotes source post: 8025199

Mine is a 99 and I had the same experience at 90k miles

How much is the replacement?

'Knocking on wood at 74K miles here...'

I've got a '99 C4 at 70,000 miles here - never had an RMS/IMS problem its whole life.

FWIW Jake, I had your / Chuck's dual row kit installed in my '99 Boxster (110K miles) a few weeks ago and the original bearing looked good on the outside and spins without friction. Haven't removed the seal to see if the grease had washed out, but we extracted about a quart of oil from the IMS tube.

the job ran about $1500 and i had the rms done too

Quotes source post: 8026894

With that much oil in the tube BOTh the inner and outer seals were compromised.. A tube filled with oil= an IMS bearing with all the permanent lube washed away.. Know that you did the right thing, when a bearing progresses that far, the wear that leads to failure has already begun. That on the OUTER diameter of the flange. The inner diameter at the stud pass through point is where oil is released out of the engine at more elevated stages of IMSBF. No seals there, just a very tight fit of about .0015 total between the IMS tube and the OD of the IMS bearing. No, it IS the only way oil can seep in. The remainder of the tube is completely sealed. The oil passes through a compromised outer seal.. It then passes into the bearing where it washes away the permanent lubrication. This leads to the inner seal being compromised and once that occurs the oil has a path directly into the IMS tube. Since the tube is empty the path of least resistance for the oil is into the tube. Are you referring to the bearing? Thats the whole thing.. The seals are still there, they are just compromised. If they were to completely remove themselves the engine's oil would completely and thoroughly lube the bearing and it would not fail as early, or at all. The seals being partially compromised is what keeps the engines oil from lubricating the bearing well enough, they actually are "in the way". Because the oil in the tube that ended up there past the seals doesn't get nearly as hot while it is in the tube, it also doesn't get nearly as thin, due to that it can't pass back through the tube to escape once it cools inside the tube. The oil within the engine that is still being used for lubrication of the components gets hotter and thinner and passes through the compromise seals and into the IMS tube more easily, it just can't escape as easily because it never gets that hot again while trapped inside the tube. The outer seal doesn't become compromised enough to allow enough oil volume from the engine to reach the bearing rollers and races, at this point the IMS bearing SEAL being compromised is what leads to IMS bearing failure. Centrifugal force that the bearing seal sees doesn't help anything in regard to seal life. Imagine if that same bearing had the outer race "parked" and the inner race was rotating instead. The seal would not move during operation. Yes. I know more about this puzzle than I've ever stated :-)

Jake.... you are a huge asset on this board. Thank You so much for your expertise!

Jake, My brothers 996 '02 just underwent a 60K checkup and the indy noted a slight oil leak. The indy also noted that he can take care of the RMS/IMS leak when he gets his clutch changed. I told my brother he is rolling the dice. Your thoughts?

Absolutely. Otherwise it's like knowing you have clogged arteries and waiting for the big one. At this point it would be an elective procedure, when things scatter he'll have no choice. If it is the IMS leaking they usually don't go very long before the big one occurs. From the calls we get the oil loss is generally noted a week or two before the failure occurs. BTW- That 60K mile service should include a water pump, AOS, IMS, RMS and clutch. The car is ready for all these things at this mileage point, but shops that just do what Porsche directs don't know this.