AA717driver

Vincent713

Do you happen to have the link to this video? This is big news to me and I like to get more info on it. TIA.

808Bill

A simple Google search will get you there.

jdoc1949

BRAND NEW IMS KIT FOR SALE
I have a 2003 Targa with 74,000 miles, decided to drop engine and do bearing and seal swap before any issues.
Pulled it apart and found out that bearing was different.
Upon Inspection found out I had a new engine fitted in 2010 under warrantee at 49,000 miles by Porsche. Its the newer engine so IMS is not an issue.
I had talked to the dealer before and asked why they did not tell me, there explanation was they only keep records for 2 yrs, go figure?.
NEW KIT FOR SALE
So I have a LN kit and a new oem seal , I paid $547 for all as I had a coupon, the LN kits are now $650 plus seal $48 ( $698) value
I will seal all for $490 to member. I have photos and receipt, brand new, along with registration card for kit, I can send photos.
John

Sapientoni

My money says many people who buy a Porsche rarely check their oil level. I'd bet when it starts making a noise is when they add oil. Porsche tested these engines for millions of miles but they checked the oil when they added fuel. These "fixes" are probably necessary for anybody too busy to comply with factory users manuals. If this 29000 mile car is "good" when acquired, just check the oil regularly and inspect it when another service makes it convenient. Clutch, etc.

AA717driver

Vincent, I’ll look for the link. It was in one of the threads in this section.

TC

amargari

I have been reading a lot about the IMS and watched the videos online. One of the contributing factors is low RPM load on the engine. In all the statistics was there ever a breakdown between Tip cars and Manual cars? I was wondering if the Tip does a better job of keeping the load off of the bearing.

Charles Navarro

In the grand scheme of things, it really doesn't matter. Less Tip cars were made, so we see less failures. In all actuality, it boils down to how it's driven. In the city, a Tip will gravitate to top gear, with the engine running at lower rpms on average than a manual car. At higher speeds, the final drive on a Tip has the engine rpm being higher than a similar manual car. It's all in how it's driven.

911Syncro

Charles, this is one subject I've been wondering about and would appreciate any additional explanation. Is there a way to understand the mechanism which is happening with higher RPMs? I know this is common advice, that higher RPMs help prevent the IMSB from failing. But what is really happening in this circumstance? Is there more oil splashed on the bearing? Does the oil stay fresher at higher RPMs? Do higher RPMs relate somehow to the oil contaminants? Or in the circumstance of the IMSB seals failing, and the "lifetime" grease coming out, do higher RPMs help to drive that old grease out so oil can get at the bearing? Is there some relationship between higher RPMs and the way the ***** in the bearing behave? Sorry for all the poor guesses, it is only to illustrate the further insight I'd be interested to understand. Thank you!

Charles Navarro

It has to do with hydrodynamic lubrication. At higher surface speeds, less oil is required to properly lubricate the bearing. Think about it this way - there is a fixed load on the bearing. At higher speeds, the ball spends less time at a given point as the ball is rolling (or sliding) faster. This is obviously an oversimplification, but it gets the point across. Porsche realized this and went to the 6305 bearing to increase the surface speed, which as a byproduct, also restored the load capacity the original dual row bearing had.

amargari

So spinning the bearing faster reduces the amount of load on a given surface at a given time. I find it funny that the 70s GM Super T10 transmission I rebuilt had a roller bearing that survived for over 100K miles without issue but Porsche was having an 8% failure rate at half that mileage. Granted, the T10 doesn't have a side load on it and that may be part of the issue. Also, the roller bearing in the T10 wasn't sealed and relied on splashing from the gear oil in the transmission.

Charles Navarro

Yup. As I've said many times, if Porsche had just keep the dual row bearing and left the seals off, I don't believe we'd all be having this discussion now.

AdamIsAdam

I've wondered about this over and over again this after watching Jake in the PCA video. I thought maybe it had to do with centrifugal forces. But you're saying the load is fixed, and at higher speeds the lubrication needs are reduced reduced because of hydrodynamic lubrication. Based on this link, it appears that at higher speeds, the ball bearings basically hydroplane. Interesting!

DBJoe996

New term for 2019 - hydroplane your IMSB! Love it....

AnthonyGS