Bravo One U Joint replacement?

[Ranman]

I have a 97 18 Classic with Mag 350 / Bravo One. The boat has around 200 hours on it and due to low lake levels, I have to spend some time idling in gear with the drive way up. I've heard this strains the U joint in the drive and in the interest of prevention, I would like to replace the joint before anything goes wrong. Is this a good idea or is the joint service life much longer than 200hrs? Would someone please post the procedure for removing the drive, changing the joint and reassembly? Is there an alignment procedure that must be followed when re-installing the drive?

[Tidbart]

I can't answer your question about strain, but I can offer this advice... Invest in the Mercruiser Service Manuals. If I remember correctly, there are 2 books which will cover the 5.7 litre and the Bravo. They are loaded with info and direction. I have the same power on my 18 and use these books all the time. $75 bucks is much less than $70/hr for a mechanic.

[Tidbart]

Also, this website is an excellent reference for parts, part numbers, and assembly. It does'nt tell you how to do things but nonetheless it is good info. It has complete microfiche of the Bravo drives and the engines with parts numbers and a price to use as a reference.
http://216.37.204.201/mercruiser_oem/mercruiser.asp?Type=11&SubType=111

[AVickers]

If it ain't broke, don't fix it. Next time you have the drive off for something, check it and change it, if necessary.

U-joints almost always give notice that they're going bad...rattle and vibration, especially when turning under a load. And when/if they do, it's usually time to replace the gimble bearing and bellows as well.

Even when in really bad shape, a u-joint will almost always still work...I don't know of one totally failing and coming unpasted. So it's not really a safety issue in terms of leaving you stranded in the middle of nowhere.

[Rootsy]

when they come apart it ain't a good thing... trust me, it's UGLY... REALLY UGLY!!! i've seen it first hand a few times in merc alpha equipped boats... pretty much looks like a granade went off and you start taking on a lot of water and you can't move and generally stand a good chance of sinking... on one boat that the tow service brought in there was no gimble housing left... and the sterndrive was sitting at the bottom of lake erie.

you will generally know when a U-Joint is getting bad by the growling noise you hear when you turn right and left. this is generally caused by lack of lubrication in them so it's worth it to pull the drive every spring and inspect and squeeze new grease into em... spin the gimble make sure it isn't rough and squeeze some new grease into it also... also put some grease on the input splines so that they don't wear out the splines in the coupler and more importantly don't seize up. also a good idea to change gear lube in the sterndrive if you put a lot of hours on it the previous year and grease the splines on the propshaft.

the bravo is heavy yes but it really isn't all that difficult to remove and only costs a few bucks for a mounting gasket and the best way to avoid problems are with regularly scheduled PM's.

[Voodoocanoe]

Randy, Lots of good advice in the previous replys, It is always a good idea to remove the drive every season to grease the u-joints, shaft splines, check the engine alignment, and inspect the gimble bearing, coupler, boot and shift boot.

I have a Bravo alignment tool and you are welcome to borrow it.

[MR MAGOO]

I agree with the others, pull the drive and grease every season.Check the water intake hose for cracking and check the drive bellows to see if it is pliable,they get hard and crack = big leak!
Last summer I had a boat come in, the u joint had exploded and it was real ugly, the entire ring that the bellows clamped to was totally destroyed. I had to replace the entire transom assy.Big money spent that could have been prevented by some simple maintainence

[AVickers]

Hmmm,

I wonder what the units w/ the hand grenaded u-joints sounded like and for how long? I can't imagine a u-joint being so bad as to come apart and not making so much noise and vibration that even an idiot wouldn't notice something wrong...

I still find it hard to believe that a 200-hour rig would need new u-joints. But, the drives are relatively easy to remove and replace, so go for it... I'm sure Merc can use the money.

I can have mine off, serviced and back on in less than an afternoon.