offshorexcursion

iTrader: (5)

Sorry to hear about your troubles!

This is just part of owning a bravo based boat, stock is bad enough but with power ranges like you and I have we are just asking for it!

Just FYI, it doesn't take much metal on the magnets at all to show a problem. Anything more then basic "dust" and something is wrong. Tiny Tiny metal shavings the size of a wood splinter in your finger are actually bad.

cp5899

iTrader: (1)

If I only get 4 miles per drive then I have a boat for sale... lol

I have access to a xr upper, but it has 1.36 gears. Maybe I should look for a used bmax? I'm confused at this point because the upper looked good besides for the bearing that broke. After changing it and cleaning the drive completely I thought it was good to go. Apparently I was wrong.

What direction do I take here to have some piece of mind I will stay running for more then a day with out doubling the amount of money I have in the boat.

Thanks everyone.

Mr Gadgets

CP,
the gears you have in your drive are the old style, thin floored gears. That damage to that bearing is typical. The top cover or race will wear and crack and then destroy the bearing. Another typical problem with the old style gears is the floor will break out of them. I am guessing that may have happened after you put it back together. Just a coincedence, nothing you did wrong on assembly. The only way to know is to go back in and look. There is an upgrade kit to replace the gears with the new style, thick floored gears. The old style cone clutch won't work with the new gears and the kit includes a new shift fork, etc.
With a blower motor, you should consider a steel tower and a good top cap. The XR drives have that, but XR upper gears are not as good as they used to be, so I tend to recommend staying away from the XR gears, unless you are snapping the teeth off the helical gears. If you plan to add more power or run trouble free, consider an SCX or Bmax in your budget.
You say you have access to an XR upper with 1.36 gears. On the XR's there is only one set of uppers, and the lower gears determine the final ratio. If your present drive is 1.5, the XR would bolt on and still be 1.5. When ever you swap upper or lower, you need to verify the oil passages from upper to lower to make sure they match.

Hope that helps.
Dick

cp5899

iTrader: (1)

That does help out and explains things a bit to me. I read many of your posts and was planning on pm'ing you so glad you beat me to it. I kind of felt the lower determined the ratio, but being new to outdrives I didn't question the guy. I can pick it up for a deal so I may get it to get back running in the mean while stock up some parts to build a decent b1 with the parts you recommended. I keep reading about steel towers for the uppers, but I'm confused as to what that could mean. Is it a steel collar that drops into the top case.

If you have a suggestion on where to find the best deal on the x gear package you referenced I would appreciate the info.

Are all b1 upper cases the same? Reason I ask is the threads where te spanner nut that holds the drive shaft pinion gear in are kind of ate up a bit, but I know where there is an older b1 upper a friend has, but I didn't know if the upper cases are the same and the gears are what changed.

Last question is this. When I took the upper apart I saw nothing in the cluster of gears that looked like it could be set up to individual persons likings/specs. The only real place I saw where you could custom tailer your build was maybe by shimming the pinion gear in and out to determine how far in or out the pinion gear rides on the two other gears. Is that a correct statement or am I missing something? I build drag bikes and cut many transmissions into complete overrides and there are many ways and places to smooth out te Trans and make them hold up better. When I had the cluster apart I didn't really see how that could be custom tailored.

Thanks for all the great info. I look forward to better understanding the outdrives and my best option to take with this boat.

Mr Gadgets

The bottom of the upper case and the top cap have races pressed on what many call a tower. On the older stock drives those towers are made of aluminum, part of the case and part of the cap. The tower is milled out of the case and a steel one is threaded into the case. I have seen cracks after milling the tower out, that couldn't be seen prior to the removal. The tower I use, threads down into the case two inches. The Merc steel tower (in the X and XR/XZ drives) threads in, one inch.
The XR ribbed top cap has a steel tower threaded into it, I use that cap because it is well built and reasonably priced.
Setup on the Bravo is not difficult, just a lot of things to pay attention to. The gear stack spacing is determined by the shims below the thrust bearings. Gear lash is determined by pinion depth and the shims on bottom and top of the gear stack.
Not all the older upper cases are alike. You have to compare them to make sure the oil galley in the water transfer portion is the same. Older cases are thinner in spots, also. You can mix and match a lot, but you need to be careful of the differences.
A steel retainer nut will help clean up the threads on the snout, but if they are bad, then looking for another case might be an option. Shoot me an email (click on my OSO name) and I can give you more info.. Send some pics of the threads. Have you taken it apart yet to see what happened?

Have to run.. at the moment.
Dick

articfriends

iTrader: (1)

800+ hp and a 32 pitch with old style bravo parts = breakage, I have much better parts in my drive and it still wears/breaks quickly when I turn my 32 so I try to not load it that hard with tall props and turn a 30 labbed most of the time. Back when I still had old style gears, much less hp (about 650 or so back then) and stock shafts I switched from a 26 labbed that boat liked and had ran for quite a while trouble free to a non labbed 28 and broke floor out of gear almost immediately (within 5 minutes), it can be frustrating, good luck, Smitty

cp5899

iTrader: (1)

Thanks for the info Dick and Smitty.

I have not taken it apart yet, I plan on doing it this afternoon and will be sure to post back with any and all information I find.

What are your opinions on me picking up the xr upper my buddy has? Since he is wrong about it being a 1.36 since the lower determines ratio, would this be a better option while I collect parts to build a better drive? What visual ways can I verify that it is an xr drive?

Where can I get one of the steel retaining nuts?


Thanks

the deep

iTrader: (8)

You guys are taking me to school here . I see some of this in my future also . The knowledge and help here is incredible , thanks from me too guys .

cp5899

iTrader: (1)

Have an update on the drive situation for those who may be following it. Got the drive apart and it did in fact break the floor out of the forward gear, but did not break or chip any of the gears. The boat is very easy to get on plane. It comes on plane at 2400-2600 rpms so its easy to baby the drive if I can get a set of gears to hold up. I'm thinking about going with a thicker floor gear and a any other possible modifications I can do to make the rest of the season. $14k+ isn't in the cards right now since I just finished this boat and went over budget with building this blower motor. It started out as a 550hp n/a build and turned into something totally different. Silly me....

If anyone has a lead or advise on better gears or other mods I'd appreciate the info.


Thanks
Craig

cp5899

iTrader: (1)

Here's a picture of the broken gear bottom.