Metal Shavings Behind LN IMS Bearing - Need Advice!

[Perfectlap]

$679 and the PO gets a $20 fugazy?

Hmmm me thinks that shop pulled a fast one thinking no one would check.

Please post the name of the shop

Someone was clever enough not to write LNE in the part description. That way it couldn't be refuted from LN's records,
the bearing would need to be pulled to call bs on the shop's claim that the bearings were at least ceramic. Deniability!


[IMG][/IMG]

[Benjamin]

Originally Posted by Perfectlap

$679 and the PO gets a $20 fugazy?

Hmmm me thinks that shop pulled a fast one thinking no one would check.

Please post the name of the shop

Someone was clever enough not to write LNE in the part description. That way it couldn't be refuted from LN's records,
the bearing would need to be pulled to call bs on the shop's claim that the bearings were at least ceramic. Deniability!

They did write the part number, and if you google that number it appears to be the LN kit.

I purposely didn't include the name of the shop for a few reasons. As stated earlier in a quote from Buck Turgidson in Dr. Strangelove, "I'd like to wait until all the facts are in". I hastily put "LN" in the title of this thread, only to find out that it very well appears to be a knockoff cheapo bearing. Not very fair to the LN folks. I have a receipt from 4 years ago that says one was put in. I don't know if it has since been changed, or if in fact the shop put one over on the PO. If I had owned the car then and could know 100%.

I'm still mulling it over.... Right now I'm more concerned with what I need to do in order to clean everything out and getting it back on the road. I can't change the past, only deal with it.

"Gentlemen! There's no fighting in here, this is the war room!" - President Merkin Muffley, Dr. Strangelove

[cnavarro]

It sure looks like there was a prior failure and there is contamination from the original failed bearing. The bearing looks very clean on the open end that is exposed to the engine oil and sump. If there was a problem with the bearing itself, I would expect to see some kind of contamination here as well. Is the bearing actually magnetized or is the debris pattern just appear to be that way?

That bearing is likely one of ours and is probably a kit we built in late 2009 or early 2010. I would be interested in getting that bearing back to have the manufacturer inspect it since they'll be able to give us a detailed report for that bearing and verify it is indeed one of ours since we have used JAF and other manufacturers for races in the past. We switched to IJK over for years ago according to the manufacturer.

All LN bearings have always had a seal on the back side of the bearing that faces the IMS tube to limit oil intrusion into the IMS, but not stop it. It's not possible to prevent oil from getting by the seal completely.

JAF is a well respected Japanese brand. Our supplier use their races and cages. Then the bearings are assembled for us with Japanese or US-sourced ceramic balls. Currently we use both SKF and Cerbec balls, both USA made. Timken / Fafnir make ceramic hybrid bearings, but not the balls themselves as they buy their balls from Cerbec as well. Everything is measured and every bearing is blueprinted. LN bearings don't just come off a shelf somewhere and get re-labeled. We use the best bearing guy in the industry for ceramics. If you go to a Motion Industries and try to order an ultra high end ceramic hybrid bearing, all roads lead to him. We have always from day one used the same source and went to him because of his reputation and quality.

[Benjamin]

Thank you for the reply, Charles. If anyone would know the LN suppliers, it would be you. I'll PM you in regards to the bearing inspection.

[woodsman]

It looks like the whole bearing has been spinning in the bore- no? Those chips may have come from the face of the bore- where it's shiny. Got telescopic gauges and a 3-4 micrometer?

[Perfectlap]

Originally Posted by Benjamin

They did write the part number, and if you google that number it appears to be the LN kit.

I purposely didn't include the name of the shop for a few reasons. As stated earlier in a quote from Buck Turgidson in Dr. Strangelove, "I'd like to wait until all the facts are in". I hastily put "LN" in the title of this thread, only to find out that it very well appears to be a knockoff cheapo bearing. Not very fair to the LN folks. I have a receipt from 4 years ago that says one was put in. I don't know if it has since been changed, or if in fact the shop put one over on the PO. If I had owned the car then and could know 100%.

I'm still mulling it over.... Right now I'm more concerned with what I need to do in order to clean everything out and getting it back on the road. I can't change the past, only deal with it.

"Gentlemen! There's no fighting in here, this is the war room!" - President Merkin Muffley, Dr. Strangelove

Apologies to this un-named shop.

Although their pre-IMS swap inspection procedure looks like a question mark.

Was this car a low-miles garage queen before the PO took ownership? (as in it sat for long periods between oil changes).

[Benjamin]

Originally Posted by woodsman

It looks like the whole bearing has been spinning in the bore- no? Those chips may have come from the face of the bore- where it's shiny. Got telescopic gauges and a 3-4 micrometer?

No, the best I have right now is a dial caliper.

Originally Posted by Perfectlap

Apologies to this un-named shop.

Although their pre-IMS swap inspection procedure looks like a question mark.

Was this car a low-miles garage queen before the PO took ownership? (as in it sat for long periods between oil changes).

I'll have to look back at the stack of paperwork that came with the car. I think I'm the 5th owner. 72k as of 2010 and just over 80k now.

[cnavarro]

I will say that the single row bearings are not tolerant of debris at all where we know the dual row bearing will take much more abuse and just keep chugging along even laden with FOD (but not indefinitely). It's quite possible a PO had the IMS Retrofit procedure carried out as a reactionary repair because the original bearing had failed.

I would be curious to see what's in the sump.

There usually isn't tell-tale signs of damage to the intermediate shaft like there is with a single row bearing so it's hard to get a complete picture. As part of our qualification procedure when rebuilding an IMS, we spin test the shaft and check for runout in the gear and housing bore to detect damage to the intermediate shaft because often shops send us IMSs with the original bearing already removed so we don't know what condition the original bearing was in.

[Benjamin]

Funny you should say that because I just came in from dropping the sump. The only particles I found were all collected in the deepest part of the sump, in the circular depression in the middle of the windage tray. They were extremely fine, almost flour like. If the amount I found stuck to the back of the bearing measured a total volume of, lets say, 10, the amount in the tray would be .01 I need to find my magnet to confirm that they are ferrous, but I think they probably are. There were several "worms" stuck in the oil pump screen. Thankfully I had read about that today and know they are Loctite 5900 that was probably over applied to the mating surfaces.

[Jake Raby]

Now you have to find where the source of the material is before you can go further.. If not you'll just have another failure.

[rp17]

Benjamin, just checking in on you with your situation. Any updates?

[JayG]

Originally Posted by DennisAN

That IMS bearing appears to have plastic seals on it. Don't genuine LN bearings have NO SEALS on the sides?

The bearing race is marked "SPC". I did some Googling and SPC generally notates a ROLLER bearing. I'd guess a roller bearing with considerable side load would generate metal chips.

To quote General Buck Turgidson, I hate to judge before all the facts are in, but I think your PO may have been had by an unscrupulous shop.

Be sure the CRM 114 Discriminator is armed

[Benjamin]

Originally Posted by rp17

Benjamin, just checking in on you with your situation. Any updates?

After spending a couple of days thinking about it, I have decided to clean out the tube as best I can, install the new bearing and DOF, and reassemble. I spent about 8 hours this weekend doing just that and am waiting for the sealant and new oil plug to arrive this week. I ordered Loctite 5900, but have since read that Drei Bond is a better way to go. I am going to call the local VW dealer and see if they have it or can get it fairly quickly, otherwise I will place another online order.

In the end it turned into an economic decision. I do all of my own wrenching, short of internal engine stuff. I have done that type of work before, but never on a Porsche and I don't have the specific tools or knowledge for an engine tear down and rebuild. I could acquire the tools and knowledge, however, when rebuilding an engine there is no sense in doing just the part you think needs to be replaced, you should check and replace everything necessary from pulley end to flywheel end if you're already there. Since I would be having a shop do the work, the bill would be in the $12k range, give or take. A used 3.2 is around the $5k mark and a used 3.4 is not much more than that (what not upgrade if you can?). There is an X% chance that the metal specks were from the original IMSB and a Y% chance they were from the replacement IMSB, and a Z% chance they are from some other undiscovered source. (You can decide what values you place on X, Y, and Z, but I place a high number on X because of the location of the debris). The car was running just fine when this project began and may continue to run just fine from here on out, thus costing me $0 of engine parts/work. If it does give up the ghost, I will swap it myself and be out about $5k. I know what a lot of people will be thinking, "you have no idea what the condition of the donor engine will be and could be inviting more problems". True, but most used engines come with at least a 6 month warranty and even if the 2nd motor goes poof, I will do the same and replace it, being out another $5k ($10k total + fluids and other misc expenses). I would still be ahead of the price of a rebuild of the existing engine. That's why I chose what I did.

So, I'll install a magnetic drain plug to catch any further ferrous particles hiding on the inside, change the oil every 1000 miles, and see what happens.

[cnavarro]

Just be sure that you drop the oil pan and clean everything out if you haven't already. I'd also recommend running a flush oil for a very short period. Installation of a spin on filter adapter will prevent debris from being re-introduced to the engine after it gets in the filter. Doing all of this will give you your best chances.

[Benjamin]

Originally Posted by cnavarro

Just be sure that you drop the oil pan and clean everything out if you haven't already. I'd also recommend running a flush oil for a very short period. Installation of a spin on filter adapter will prevent debris from being re-introduced to the engine after it gets in the filter. Doing all of this will give you your best chances.

Thanks Charles, I have dropped the pan and cleaned everything out. I just ordered some Drei Bond to seal it back up and it should be here on Thursday. I like your idea of running a flush oil. I have a case of DT40 that I was going to put in to replace the Mobil 1 that was in it. I may just hang on to the DT40 and get some more Mobil 1 and run it for a short period and then drain. I have a few filters on hand, but they are the stock type. Can you explain to me why the spin on is better? The OEM version is much easier to inspect after an oil change.

Benjamin

[Jake Raby]

The Spin On filter adaptor omits the factory bypass that diverts bypass oil around the filter at start up and at times of higher than normal oil pressure. During these periods the factory filter does not filter 100% of the oil. Tis is also even more true if the factory bypass spring has lost tension due to high oil temps or time in service.

The factory filter does not filter 100% of the engines oil at all times, so any debris that is suspended in the oil will take out more components. This is especially true if you are injecting debris filled oil into the IMSB.

[Benjamin]

OK, I have one on order as well as a couple extra filters. I guess that means I have some OEM type filters that I can't use, so maybe I will see if one of my local Porsche buddies can use them. Does the OEM filter housing wrench also work on the spin on filters? I see I will also need a 26mm socket for installation of the adapter.

[BYprodriver]

Sounds like you have a good logical plan going Benjamin. The filter adapter allows you to use a conventional metal filter, so a strap style filter wrench works fine. You should get a 3" dia. Filter-mag for it also.

[Benjamin]

Originally Posted by BYprodriver

Sounds like you have a good logical plan going Benjamin. The filter adapter allows you to use a conventional metal filter, so a strap style filter wrench works fine. You should get a 3" dia. Filter-mag for it also.

Yeah, I ordered one of those too. $50 for a magnet seems like a lot, but it's only money.

[rp17]

Sounds like a plan Benjamin. Good luck on many miles.