I have a TRS drive and have some play in the steering. I know its where the arm attaches to the gimbal. There's 2 large plastic plugs on the side of the gimbal but I want to make sure I have 2 to replace them before I try to remove them. Any idea where I can find these?

Mercruiser Manual #5 Stearn Drive TR-TRS covers this repair and has part numbers for the repair kit that shows these plugs. As your Gimbal plate already has these installed, someone else has already repaired this once. Question is, did they change from the spline fitting to the square fitting for the yoke, or just repair the spline fitting? Real solution is to convert to hydraulic and do away with using these undersized components.

Any Merc dealer will have an upper swivel pin repair kit. Plugs are included. Be sure it's just a loose arm and not a worn upper pin bearing.
Gary

Try these for good info:

http://www.mercstuff.com/howdoi.htm
http://www.jrmarine.com/products/gimbal_repair.htm

I had a friend move the drive back and forth while i looked at the steering arm inside the housing. Nothing moves in there. I think the gimbal ring is worn out. Now,do I put a new ring on or go to external steering? What was the name of the guys who were building their own for sale here on the website?

maybe it's me...but I would shy away from the plug method. I know its simpler to do, takes less time and is less expensive, but i tend to do things the hard way anyway, so...

when my brand new merc 350 mag mpis developed this problem in 2001, i pulled the motor in question, pulled the transom assembly and did it the "right" way...(it seemed that someone at the factory neglected to fully tighten the gimble ring and after 3 months on the water it was junk and swaying all over the place.)

now for my TRS drives, I intend to do the same, provided you can get to the components when out of the boat. I just feel that its a shame to cut holes in the transom assebbly and frankly, i think it looks like crap...but that's just me...

Well, they were already there when I got the boat, so that's a dead subject. Just looking for a solution and I don't know if I plan on keeping the TRS drive , too weak with the Merc trans. setup.

If the ring is worn, external steering wont fix it. The ring will still wobble on the upper swivel pin. I'm guessing it's a square pin since I've never seen a splined go bad. Take it apart, see what's bad and replace it. Use all new seals, gaskets, plugs, etc.
Gary