There are two different U joints for these drives listed. Early for MC1 and Alpha1 and later for Alpha1 and GEN II type, Installed mine last year and missed the size difference in the cups. Never needed to trim up when running so never felt the banging.Heard the noise and pulled the drive and you can see where the cups were banging against the center section on the inputshaft side and not touching the yoke side of the drive. The correct ones cups sit almost flush with the yoke and the other sits about 3/16 ths proud above.
So before you order them make sure you use the correct size.
18-2104 is shorter than the 18- 2174 that the caps sit proud on
First time chiming in as I finally found my password from many years ago and it still worked. Love this site!
Came off Lake Erie about 7 miles out three weeks ago when a terrible grinding, vibrating noise popped up. Worse in neutral and I babied it back to Beaver Creek in Lorain, Ohio. I decided to drag the 22' Trophy Pro back to my place in Parma and try to fix it myself as Copper Kettle Marina currently has no mechanic. The boat needs new hydraulic hoses from the trim pump to the manifold anyways, and one of the trim cylinders is shot. I was getting thru the fishing season just fine with my trim tabs until this. Turns out one of the non-greaseable U-joints dried out. Plenty to do in a short season, right? Thank God for others that post their fix's or I would have bitten off more than I could chew, for sure. Was about ready to order internal clipped 18-2174 U-joints but they didn't look like my external clipped U-joints.
I just completed replacing U-joints in my 2007 Alpha 1 Gen II sterndrive, that has a newer GNK style external clip for (OL949779 & up), also fits Bravo (OM111208 & up). Non-greaseable 18-6406 is the part number. They seem to be supplied with three sets of clips in different thickness to fit the applications. The thinnest clip barely fit mine. I keep reading that these clips are punched by a press and the process gives the clips a sharp edge on one side and a more rounded edge on the other. You have to look pretty close, but the sharp edge is supposed to be facing outward during assembly.
I got the U-joints replaced, new hydraulic lines in and decided to replace all four external hydraulic trim cylinder lines as well as the bad cylinder I could not free up. Sad to lose a month of the season but pleased I saved a boat load of cash doing it myself
