It will work. That's all I've ever used. That bearing is for an XR, merc calls their bearing a "red dot"' for an XR. It will still work for a standard bravo.

Sierra's GB for 1997 and back for Merc is 18-2100 and you can put them either way ( backwards).

Next 1998 and up Merc takes GB 18- 21005 and do not put this one in backwards - the inner portion end is a tad shorter on the end - it shaved down compared to the older GB - I think around .030 This needs to be facing out when you install it. Both of these GB are greaseable.

Sierra 18-21001 is the non greaseable (just like merc one) for anything 1997 & back. Merc started non greaseable GB in 2008 and so did Volvo penta in late 2007. FYI.

next for 1998 and up - alpha's Gen II, Bravo, X / XR / XZ - Sierra really recommends 18-21006 - this is a non greaseable GB. if I recall correctly Sierra's GB is Link Belt or GKN currently - I forgot. Mallory Marine carries the SKF - GB inwhich is good also.

The consensus seems to be it will work.

I see that the inner portion is shorter on the original Merc one I pulled out and that is where my concern is coming from. If as you say (which I don't doubt) the 18-21005 needs to be put back in a certain direction how does the 18-2100 which has a longer inner part on both sides not cause any problems?

I re-read your post and it looks like your saying the shorter center needs to be to the outside. If this is the case then the 18-2100 bearing definitely wouldn't be a problem. That makes sense now.

there is a reason for the shorter inner and as why it needs to face outward. These GB are different by design by load and the shorten end is for cleanance as to when trimmed fully & full left to right turns not to produce a slight noise. This applies to 1998 and up models from Merc.

the 1997 and back GB the input driveshaft has this clearance already plus the load is different on the bearing than 1998 and up.

We have probably installed 1000 + GB over a course of 24 years. Nobody ever pulls their drive to completely check the condition of the U-joint bellows until after the leak and the deep growl by the GB from water intrusion that has already taken place or the boat owner left the drain plug in during rain storms. Shift cable bellows is a another story just the same but alot easier to check but still nobody checks that either - not to change the subject here.

2001 boat uses 18- 21005 not 18-2100 both greaseable. You can call Sierra on this if by chance anyone thinks i do not know what I'm talking about, no offense on my end. You have to install this bearing 18-21005 correctly. Also you can call mallory Marine and Merc to verify what I'm talking about. We attend all the OEM marine schools and take all the tests and we are very current all the way up to the catalyst systems in these marine motors. FYI & Good luck.

I'm confused now. I have a 98 boat and just ordered the 18-2100 gb. So this bearing will or won't work? It's a bravo 1 drive.

Thanks

I just installed the 2100 on a 98 Model Hammer. It will work. No problems. Just install it with the dot facing out and line your grease hole up with your zerk fitting on the gimbal housing.

Forget all that installing backwards crap just because its easier. If im going to take the time to remove my drive and check everything out, Im putting a whole new bearing in with new race. Just my 02 cents.

Since I asked the questions that probably got you confused I'll give you my conclusion. Can the 18-2100 be used in place of the original for your and my model yr? YES. Is it technically the correct gb? NO. Is there a difference between the two (18-2100 & 18-21005)? YES. The difference is the center piece of the bearing is the same on both sides of the 18-2100 which means in theory the drive will not trim out as far because the shaft will bottom out on the gb sooner. Will that 0.030 difference really be noticeable? Don't know. Most people on here seem to say no.

I haven't made up my mind which one I'm going to use yet.

What about the seal I see in the parts fiche? Does that also get changed when changing the gimbal bearing? When pulling the bearing out with a puller, does the seal come out with it? How about the bearing carrier, does that come out with the bearing or stay in? Thanks.

I did not change the seal on mine when changing the bearing. I did have to turn the bearing a little in order to get the puller in between the seal and the bearing though. Then just put it back straight before starting to pull it out. As for as the carrier, If it looks like this pic with the notches on either side of carrier then you can just pivot the bearing where the notches are and pull it out.
http://i1082.photobucket.com/albums/...psa7c377eb.jpg

If it looks like this pic then you will have to use a puller and both the bearing and carrier will come out together.

http://i1082.photobucket.com/albums/...ps9b94f1d7.jpg

Thank "seafordguy" for the pics. He helped me out.