The reason LN used a Spiralock instead of a snap ring has to do with the original wire ring used in the tube; the Spiralock conforms to the grove machined into the tube better than a flat snap ring would, giving you a superior holding power.

I must comment about the quality of LN's products. Beautifully machined, they are almost works of art, worthy of a place on the mantel. Here's an exploded view of the installation tool and the bearing as it's installed in the shaft:

http://986forum.com/forums/uploads02...1740160192.jpg

Spiralock! Many thanks, JFP. I've been searching for the official designation. Thanks to you, I found a company with a trick name for theirs, Spirolox, and they have an installation how-to:

https://blog.diamondracing.net/how-to-install-spirolox

I managed to get the Spiralock installed, with the help of a small flat-blade screwdriver. I think it's fully in the groove, but I didn't have sense enough to measure the width of the lock before I put it in. Consequently, I can't be sure how much is actually in the groove, which is only a millimeter or so deep. A couple millimeters of the shim can be seen behind the lock. It seems secure. I can't easily pop it out of the groove with the screwdriver. I think it's okay. In fact, I'm almost sure it might be.

http://986forum.com/forums/uploads02...1740188135.jpg

Isn't the Spiralock flat too?

Looks great! That thing ain't going nowhere!

Seated, the bearing was less than a millimeter in from the groove, about the thickness of the shim. Which I figured was the objective. But a little voice is whispering, "What if the bearing isn't fully seated, and there wasn't enough clearance for the lock to fully engage in the groove?" I hate that voice. The only way to shut it up is with experience, but this is the only IMS bearing I'm likely to install. At least, I hope it's the only one.

By the way, not to stir the pot again, but Jake Raby refers to the Solution's bearing as a "bushing" here, at 18:12:

https://www.youtube.com/watch?v=XZ87UcYkT7A&t=892s

Yes, but because of its spiral sectional design, it can better conform the bottom of this grove, which is slightly curved, much like a "U" to accept a round wire. A snap ring would not fully seat in this grove.

Got it. thanks.

I examined the Spiro-loc (which is how the manual spells it) with a magnifying glass and was satisfied it's in the groove, baby. So I proceeded to install the flange, taking great care to insert it evenly so as not to pinch its triple seal or disturb the stud's o-ring. I'm ready to torque the flange bolts and center stud nut, but I encountered an unforeseen problem. Seems my 7/16" box end won't fit into the flange's notch and allow me to tighten the nut (while holding the stud with a screwdriver) enough to start torquing it. No room to get it on the nut. I'm stymied. A possible solution is to find a wrench that's more svelte than the one I have. Don't ya just love those unexpected work stoppages?

http://986forum.com/forums/uploads02...1740277051.jpg

Been looking at wrenches on Amazon. Most of them look like mine. I added "thin-wall" to the search and it came up with this set:

http://986forum.com/forums/uploads02...1740280130.jpg
https://www.amazon.com/HORUSDY-11-Piece-Wrench-Combination-Organizer/dp/B0C9W2C34M/

More cheap Chinese tools, but I figure for what they cost, if the set's 7/16" box end works on that one nut, I will consider it money well spent; otherwise, I'm out only fourteen bucks. To my eye, these 12-pt box ends do look perhaps a millimeter thinner than on the ones I have. They'll be here tomorrow and then we'll see.

Why, you may be asking, does LN use both metric and SAE? That's a good question. The oil-line fittings are metric, but the Solution Supplemental kit provided a 7/16" deep socket specifically for that one nut, which came in the bearing kit for the stud. Wish they had included a 7/16" box end I could get on that nut.

Perhaps you'd be better off with one of these pass-through sockets:

https://www.harborfreight.com/sae-and-metric-pass-thru-socket-set-21-piece-62305.html?utm_source=google&utm_medium=cpc&utm_ca mpaign=21901739207&campaignid=21901739207&utm_cont ent=171677809102&adsetid=171677809102&product=6230 5&store=496&gad_source=1&gclid=Cj0KCQiAq-u9BhCjARIsANLj-s2nkJNBm1KzUzJU4wwXF8mwDPMCKJ1H48bAjB74_eW5FNLna8e AnpgaAi3_EALw_wcB

Your problem seems to be more of a depth issue than a clearence issue. These are sockets that are open all the way through so you can use a screwdriver to hold the bolt. At the same time, like every other socket, they can reach in and tighten the nut.

You may want to review the Jake Raby procedure on YouTube that you cited as what you are experiencing is shown around 20:54 of the video.

I saw that too, unfortunately the video kind of speeds past that. Shows him using a socket and a screwdriver and then cuts away to him using a torque wrench.

Thanks, you guys. I already tried the socket/screwdriver method yesterday, but I can't seem to get the nut tight enough so that the stud doesn't turn. It needs to be fairly tight before it can be torqued. I'm going to try again, turning the socket with vice grips, protecting it with a shop rag. The problem is that only a small screwdriver will fit through the socket, seemingly too small to hold the stud. Nevertheless, after working on it all night in my dreams, I'm going to have another go at it. The hopefully thinner-walled box ends won't be here until later today anyway.

Were you using a 7/16 with a 1/4" drive or 3/8"? You'd fit a larger screwdriver if you have one with a 3/8" drive. And the passthru sockets from Harbor Freight have an even larger opening.

Hopefully I'm wrong, but I suspect the thinner box wrenches may not me much help in this situation.

By the way, the manual states, in Step 38: "Using assembly lube, lubricate IMS Solution bearing and install IMS Solution flange into bearing by hand. Then using a soft face hammer, lightly tap the IMS Solution flange until is is flush with crank case."

Right. But when getting it the last quarter-inch or so to make it flush, I forgot about "lightly tapping." Making it absolutely flush required a couple dozen mighty blows with my 45-oz rubber hammer. After driving in the bearing and now the flange, my right arm is beginning to look like Popeye's.

I did everything I could to facilitate an "interference fit," as my friend the metal fabricator calls it. I kept the flange in the freezer overnight. The place I'm working in is unheated, but I placed a heater to direct heat at the opening for a couple hours, until the crankcase felt warm to the touch. I coated the appropriate surfaces on the flange liberally with assembly grease. I don't know what else I could have done. I think I was bitten by the machining-variance situation.

The screwdriver won't quite fit through my borrowed 3/8"-drive socket. There's a structure halfway down, no doubt to add strength, that won't allow a screwdriver of sufficient size to go through. Also, it has a shoulder on the outside that won't quite let it seat all the way on the nut due to the narrow notch. A friend is coming over with a 1/2"-drive 12-point 7/16" deep socket, which might be just the ticket, if it's slim enough to fit in the notch.

UPDATE: My buddy's 1/2"-drive deep socket won't fit in the notch. I'm checking Amazon for a 3/8"-drive deep socket with overnight delivery. If that doesn't pan out, I'll make a run to Harbor Freight and Home Depot. And I will drill that sucker out if that's what it takes to get a screwdriver through it and on the stud. By the way, all the pass-through sockets I've seen have shoulders that will make contact with the notch and prevent them from seating on the nut.

I could grind the shoulder off the 3/8"-drive socket I have, and enlarge the inner structure. I have the technology. However, I borrowed the set it came from and it's owner might not appreciate it.

Found this individual 3/8"-drive 7/16" 12-point deep socket on Amazon for $5.99. It looks perfect — except delivery is Mar 1-4. I don't want to wait that long. Stymied again. I tell ya, this is sexism and rank misogyny, pure and simple! Why, I oughta...

http://986forum.com/forums/uploads02...1740344476.jpg

UPDATE: After giving it some thought, I realized I could leave the flange and nut untorqued and complete the rest of the Solution installation and perhaps install the rear main seal while I'm waiting for the socket to arrive. If the $14 box ends are a bust, I'll order it.