I couldn’t find any new old stock under the 916 prefix number. I’m machining a fixture to hold the new bearings and turn them down to the size my old bearings measure.

Depending on my outcome, and I feel 99.9999%, I’ll offer to the community to machine anyones bearings to the older dimensions.

Granted a little neanderthal, but since the shoulder height of the bearing is relatively non-critical, would it be acceptable to remove .8 mm or whatever the correct amount is, using a belt sander (very carefully of course)?

You could grind the edge on a rock until it fits. THAT would be Neanderthal. The edge of the thrust face isn't critical.

Just measured the layshaft bearings I acquired recently, and they are 5 mm. I think the video mentions this is the "old" measurement and would be OK.

That is the smaller of the two. What number is on the box, and where did you say you got them?

I am getting ready to assemble a 3.0L SC engine and read this post. I had just purchased the latest Glyco IMS bearings.
http://forums.pelicanparts.com/uploa...1707099604.jpg

I did not have the same issue with them sitting high mine were flush.

http://forums.pelicanparts.com/uploa...1707099716.jpg

I decided to check some of the other cases I have to see if there would be a issue. I found Porsche factory bearings in the two I checked. One had 916 series (86 930 case probably factory installed) and a previously rebuilt 2.7 with 993 prefix bearings. I tried the new Glyco in each case and found it fit the same as pictured.

http://forums.pelicanparts.com/uploa...1707099928.jpg

http://forums.pelicanparts.com/uploa...1707099977.jpg

When I compared the 3 bearings the 916 and 993 appeared identical. And the bearing surface is .9 inches wide.

http://forums.pelicanparts.com/uploa...1707101265.jpg

The 996 version has a couple differences I can see so far. There is no hole drilled in the bearing, the thrust face is a little wider and the bearing surface is wider at 1.05 inches.

http://forums.pelicanparts.com/uploa...1707101426.jpg

All three bearings appear to be the same height at .68 inches from table to highest point on bearing. Left to right 916.993. 996.

http://forums.pelicanparts.com/uploa...1707101591.jpg

http://forums.pelicanparts.com/uploa...1707101692.jpg



Based on what I have measured so far I would prefer the 996 version for the wider bearing surface.
http://forums.pelicanparts.com/uploa...1707101781.jpg

I purchased some NOS 916 bearing and will measure to see if there is any difference in clearance when they show up.

John

I got mine from a friend who is an engine builder, and they came without a box, so no part number. Here’s a picture though in case that helps. Both flanged bearings measured 5.1-5.2 mm. Perhaps noteworthy that they appear to have a 2020 date code.


http://forums.pelicanparts.com/uploa...1707102583.jpg

Well after spending some undisclosed hours, ok I’m retired… doesn’t really matter…

I machined a lathe fixture to hold an IS thrust bearing to machine it to fit early engines.

http://forums.pelicanparts.com/uploa...1707279919.jpg
http://forums.pelicanparts.com/uploa...1707279919.jpg
http://forums.pelicanparts.com/uploa...1707279919.jpg
http://forums.pelicanparts.com/uploa...1707279919.jpg

I wish the interchange would get straightened out across the board. Not much chance of that since the central authority (Porsche’s parts manuals), has it wrong in all there manuals, (1965-1969), (1970-1973), (1974-1977), (1978-1983). They all show the 993-101-137-01 as compatible and the superseded part number. Vendors look at that as the gospel. What are the chances Porsche will correct this?

Mods:
Maybe a sticky note is in order

Hi
Looking at the very first photo:
How can you be sure that the bearing shell is seated correctly in the case ?
(You cannot see because of the shell thrust faces.)
Suggest you fit both bearing shells and carefully assemble case halves and watch what happens as the adjacent case bolts are torqued up.
Do the two bearing shells seat correctly ?
Is the inside bore diameter of the installed bearing shells within limits ?
Best regards

Magyar Kiwi, read the whole thread. There is a problem with the later bearings, with respect to flange diameter, in the engine cases prior to the 996 engine. If the bearing half is sitting proud.015” and the same for the second half, that’s .030”, the case will not close and that .030” is way off any intended bearing crush. After I machined the bearing outer flange diameter to the diameter of my removed bearing, they nested where they should be. I researched the part numbers in all the current porsche parts manuals that are available on the Porsche website all the way back to 1965 year model and the 996 part number shows up. It seems to me that the manuals are living manuals, meaning Porsche updates them from time to time. The problem started throughout the parts network because Porsche made an error with supersedure. One gentleman had unfortunately assembled his engine and had a leak because of this bearing causing a gap in the case.

Hi
Thank you for the clarification.
The key information is in the youtube link at Post 14.
I have now watched it.
Best regards

Porschedude996, I disagree with you conclusion that all the 996 int shaft bearings are an issue.

"There is a problem with the later bearings, with respect to flange diameter, in the engine cases prior to the 996 engine."

I have the same part number 02 8005 Glyco bearings (996 part number on box). They appear to be made 12 of 21 (not the best picture).

http://forums.pelicanparts.com/uploa...1707801765.jpg

I did not find the same issue you did. I installed the 996 bearing in a 3.0, 3.3 and 2.7 case and none had the issue you experienced. The bearing was flush in all the cases I tested.
Maybe it was a limited production issue or there is a difference in how your case was machined.

I purchased a set of NOS 916 bearings.

http://forums.pelicanparts.com/uploa...1707802619.jpg


I measured the bore diameter with a bore gauge after bolting down the case halves comparing the 916 and 996 bearing. I found they were almost the same (the 916 bearing was .0005" smaller), which given the clearance range is nothing.
Based on my case fitting and my measuring as saw no issue with using the 996 bearing. With the wider bearing surface of the 996 bearing (measured in earlier post) I would prefer the 996 bearing to earlier 916 or 993 bearing.

john

Huh, I took a look at my original bearings and they are stamped with a porsche number of 916.137.00. They fit my case perfectly, the superseded to the 996 number didn’t fit. I find no reason to measure the inside bore, I know it’s going to be good when the bearing doesn’t sit proudly above the case mating surface. My .015” height surely was not going to allow the case to close.

http://forums.pelicanparts.com/uploa...1707856509.jpg

This post and the Breitworks video really freaked me out!

I'm getting closer to closing up my 2.7 case, so I ordered a set of bearings from our host. They were not marked where they were made. I put them in to see how they looked, and they seem fine to me. I can barely catch a fingernail across the tops.

http://forums.pelicanparts.com/uploa...1708205236.jpg

http://forums.pelicanparts.com/uploa...1708205236.jpg

My brain is scrambled at this point…;)

I dunno... he didn't torque both sides of that bearing down.. so that dichem test isn't valid is it?

http://forums.pelicanparts.com/uploa...1708424633.png
https://i.imgur.com/h8PchgY.png