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Having issues with Glyco rod bearings in 1990 964 3.6. Assembled rods to crank and several were way too tight, like zero clearance. Stock size polished crank, resized rods. I had no way to check id of rods, so I went back to machine shop to recheck. They checked them and verified them ok. Reassembled, still no clearance. Disassembled again and measured rod bearing shell and found this. Shell measured at edge to eliminate error from curve of bearing, one shell varied from 0.053 to greater than 0.064. Obviously not going to work. Is this the problem others have seen? What are alternate bearings? Returning them for exchange, but this is very worrying. My research is that rod bearings have eccentricity, ie they are not a consistent thickness all the way around, but they are thicker in the center, and have the most clearance at the parting line. Thickness varies in the .0005 to .001 range, certainly not 0.011. Very strange. I have measured the whole set and they have 0.005 difference from thickest to thinnest in the center of the bearing, 0.005 difference from thick to thin on the flat side(opposite the tang), 0.0035 difference on the tang side. Bearings have 05-14 date. Box says Made in S. Africa

Has anyone ever seen bearings vary this much?

Return them and get either the Clevites sold by Auto Associates (can buy through Pelican) or call Steve Weiner and ask about his bearings.

My 02-10 German Glycos did not have that issue, and and the plastigage check (3 places in each bearing) came out perfect.

There was a thread on this very subject only a couple of weeks ago and even Wayne got into it.

Walker... this thread is more than 6 months old.

I find Pelican's lack of education to its sales people frustrating. I called looking for rod bearings and the sales person didn't know anything about what was going on. Needless to say they didn't get my order. This was in regard to 944 bearings, and now I will shortly have an order for 964 rod bearings and its looking like Pelican will not get that order either. It makes it hard to buy parts from them when their people don't know what the hell they're talking about. I'd rather pay a few bucks more and buy direct from supertec or Steve W, and have confidence that I'm getting the right thing. In the past I've almost exclusively bought parts from Pelican....Wayne, are you listening?

I am returning the above bearings. I have a set of Clevite's from AA on the way. Will measure the same way as I measured the these bearings and post the results. Should have them by the end of the week.

I can't find a spec on the Glyco's, but I guarantee it is not for a rod bearing to have a 0.011 step at the parting line, and that is exactly what I was getting. The largest measurements were mostly on the tang side and the smallest were on the other side.

You sure your case is aligned?

Case alignment effects main bearings but not rod bearings.

So much for pelicaning and driving. Meant to say rod. Are you sure your rod is aligned. Numbers on the same side...

Not sure what you are asking. The rods aren't even on the crank yet.

With a little digging, I found a Clevite book that specified 0.0003 tolerance per bearing shell. These Glyco's have over 30 TIMES that amount.

Some of them have reverse eccentricity, where the shell is thicker at the parting line than at the middle. As far as I have been able to determine, there are absolutely no engines designed that way. There are only 3 shells out of the 12 that belong in an engine, and they are marginal. There is no possible way a bearing shell should vary in thickness 0.011 between it's own parting lines. How in the world did it make it through any sort of quality control?

Yes, rods are assembled correctly, and double checked by the machine shop. I went back to square one several times, because I couldn't believe what I was seeing. I even ran the numbers on the Federal Mogul-Glyco website to check to see if they were counterfeit. Apparently just poorly made.

Dear smokintr6,

I would like to apologize for your experience with our Sales team. Our goal is always to make sure the customer receives the information and parts needed and that they continue to be a part of the Pelican Parts family. Our Sales team is dedicated to providing only the best service and providing you with accurate information. We are more than happy to address any questions or concerns you may have. You can always reach us at (888)280-7799. We are here to help!

Thank you,

Javier Jauregui | Customer Service & Sales Manager Pelican Parts Inc.

Mark,
I still haven't bought my rod bearings for my 3.6. If I call and talk to a sales associate now will they know what I'm talking about when I say 911 rod bearing issues? If I get the AA brand from your website they will go in a stock rod and do not have the reputation for failure and being bad right out of the box? My engine is apart due to a chain ramp failure, and I'm really trying to do a budget build, but I don't want to do it twice.

I highly doubt you're going to get any knowledge of rod bearing failure history from a sales associate. They know the catalog but not these sorts of "urban legend" issues out there. There's still a question as to whether the issue is really truly an issue.

That said, AA created these bearings for a reason. Because they experienced the problems first hand and were not willing to take the risk again. The rod bearing you appear to need is the STD size 930-103-147-15-M987, which is a bearing that fits all 3.2, 3.3, 3.6 rods thru 993 engines. If you're not convinced, call them up instead of talking to Pelican. I'm sure they'd be happy to talk to you.

Specializing in Porsche, Audi, VW, BMW and Mercedes with our Body Shop, Race, Restoration & Mechanical Services - Automobile Associates

Just to add fuel to the fire I actually had this discussion with someone today, sole and separate from this thread or any other.

I was assembling a crankshaft with Clevite bearings and the subject came up. My friend mentioned in passing that he's recently heard about A LOT of engine failures across the country from various shops that got burned by Glyco bearings. Apparently there was a change in Glyco manufacturing which resulted in the bad bearings.

As this thread has eventually come to, the "fix" is to step up to the Clevite bearings and be done with it.

Clevite, NOS Glyco or recoated used old Glycos (if in spec). That's all. I got lucky enough to find 80s vintage NOS Glycos for my 930.

Sent from my Nexus 6P using Tapatalk

Since this thread has come up again, the link below is real data(not "urban legend") that I measured using glyco rod bearings. No question they were defective. That said, the question becomes, where they an anomaly? The only answer is to measure everything.

http://forums.pelicanparts.com/911-engine-rebuilding-forum/856995-glyco-vs-clevite-rod-bearings-data.html

Without getting into a lot of typing, my intent by saying "urban legend" was because the jury is still sort of out in that there isn't wholesale buy-in that this bearing issue is a manufacturing problem. That said, when you've got a shop like Automobile Associates going out on their own and having Clevite make bearings? That's very telling. So i'm certainly not one of those who is yet to believe there's a Glyco problem.

I, for one, will not be using Glyco bearings in my upcoming rebuild. But I do have a question about the measurements that onevoice did above on rod bearings that were installed. Could a contributing factor to the large various noted in bearing thickness have been the very fact that they were installed? I understand that bearings squish a little when installed and everything is torqued down. It seems reasonable that this may result in a some distortion on the ends of the bearing shells where they touch when installed (and where it appears onevoice measured) ... I am speculating here, and have no idea how much if any distortion is to be expected due to squishing.

Scott

I will go by our local Porsche dealer in Newport Beach CA and order a set and see what comes in or maybe they can tell me what brand is OEM these days... more later

Cheers

Because of this thread I spent the money on GT3 rod bearings for my 3.0. 4000 miles later still good. But the real test will be at Watkins Glen in a few weeks.