Hi,

I have a 1990 454 Magnum with a Bravo 1 drive with nise cone turning a 28" bravo 1 4 blade prop. Its pushing a 20'7'" Eliminator v-bottom with a raised x-dimesion 3" higher than stock.

And the top gear wear the drive shaft enters the upper lower unit, has split.

What would cause that?

What can be done to improve it?

Is this common?

Would a drive shower have saved it?

Had that happen to me a couple weeks ago, yes it's common. Usually caused be re-entry into the water after getting air from a wave. You need to back off on the throttle when out of the water, then get back on it when your back in the water. The shock on the gears when re-entering with out backing down is too great for them to handle. you can get away with a few that you miss. but eventually you will break them. Also, the more HP you have over 500hp. The more often they will break The XR drive is a little more beefier.

Thanks for the info, are there any better gears that will fit my drive? I assume the XR has a different housing.

What is the purpose of a drive shower? How dod you tell if it is needed? (my understanding is if you see white chalky stuff on the drive cap than it is running to hot)

I don't see that, but it does get hot that you can't touch it for very long.

There are a few after market HP shops that sell gears.

A drive shower does not help in this case, and yes if you have that white chalky stuff most likly your out drive is running hot.

If its too hot to touch, you need a shower. Period!

Love to see the brave sole that will hang off the transom while under way and touch the out drive Because once you come to a stop, That outdrive cools to fast being under water an all

Not always the case. I noticed lately that I can run at cruise speed w/o any WOT runs, come off plane and idle thru the marine, back into my slip, then wait for the lift to lift the boat out of the water. (approx 5 min of the drives being in the water) Then while wiping the boat down, I can still feel some heat in the drive uppers. This is using a shower too.

have a drive guy have a look...i can't see from here, eating ice cream on my couch, to provide you with anything besides... irresponsible speculation.

you should be able to run standard gears...the gears that would replace yours are updated and are less prone to having the floor blown out of them.

drive showers...really don't do all that much...but...

you may (do it) want to have a good prop shop look at your wheel...inaccuracies WILL cause excessive gear wear and or damage due to vibration torsionals....this is also true on the other end...gimbal bearing, u-joints, and engine alignment... good time to have a look at the system as a whole...always sucks to spend money on the effect,,,not the cause(root that is)...good luck...lets us know what they/u find?

Thanks gang for all the info.

Mercruiser no longer sells just the gear set, and it comes in an upgrade package, which includes gears clutch & ??, the gears are stonger. The drag is the package is $1,400.00 can$$ + install. So my alternative is buy a used 1998 bravo 1 drive for $2,800-$3,200 Can$$ But then I have a used drive that still needs to be repaired.

A bit of a catch 22, but I like the idea of fixing my drive (which has a nose cone) and saving a few bucks and not having the hassle of selling the old drive (repaired or as-is)

Any thoughts??

Thanks again!

Too hot to touch is too hot? Not necessarily. A little over 140 degrees is too hot to hold your hand on. Not arguing that it's "too hot", just that it's hard to tell with touch.