Bravo XR drive life
 

I recently purchased a Formula 353 with 600's and Bravo XR drives. On inspection there was metal on the drain plugs so we tore down both drives and there was some signifigant gear wear. We are going through both drives.
The drives have about 100 hours on them and since I just got the boat I really don't know much history as far as how hard they were run or when or if the drive oil was changed. I do know that there weren't any drive showers, but I have added them now. Just wondering is this typical or if I am easy on them can I expect better life out of the drives than this?
What are your experiences?
Thanks in advance.
Dave

I have the same 600SCI/XR set-up as you in an 07 38 Fountain Full Stagger. The drives seem to need going thru every 100hrs, they both have been done twice on our 220 hr boat. I also had an 05 353 with 525/XRs and the drives lasted 300 hrs before rebuild for comparison. Seems the 600s really max the XRs out, Merc should have only offered the NXTs. Being smooth getting on plane, applying throttle in a ramp up style to achieve top speed, and throttling correctly when in the air will definitely help the XRs live a longer life.
Also my boat didnt have drive showers on it when I bought it, they are cheap insurance don't understand why the previous owner didnt run them. Worst scenario the case will run cooler, best case oil will drop some temp. I have run with and without showers and case temp difference was substantial.

Try heavier oil like Amsoil Severe Gear 75-110 or 75-140, yeah, you lose 1 MPH on top but they dont chew up the gears as fast. Some guys are getting better results with X gears as well.

There are several ways to get more life. Several threads about it - depends on what works best for you.

I would think about upgrading to IMCO's or something else if it turns out you will be laying out significant $$ to get your drives fixed. I've heard pretty good stuff about All American Drive Service upgrades.

Thanks for the info guys.
My mechanics said the drive showers will lower opperating temps by as much as 30*, that should help.

That will help. But dont kid yourself. Its a band-aid on a flesh wound.

Things that helped me:
1. Choose an oil heavier than Mercury HiPo gear lube.I pump in 1 qt of 140 and fill the rest with 110
2. Aftermarket top cap with 7/16 studs - this made a big difference for me. I think the higher bolt torque makes a big difference.
3. Have someone that is competent rebuild it to real specs. Not some jackass that can rebuild a "bravo".
4. Good drive shower or aftermarket cooling system. The cooling system worked wonders but then your spares have to be drilled for oil lines.
5. Im seriously considering going back to X gears to see how they hold up.

Yeah, there are a few shops that can perform miracles but I cant see spending $7,000 on a Bravo XR rebuild. If you are going to drop 7-8 grand buy an SCX

If you drive oil smells burnt/cooked after 20 hours your drive is not going to live. My NXT oil looked as good draining out as it did going in after 100 hrs, thus no failures. These big HP engines just are too much on gears the same size as a VW transaxle. Heavy boat and 100% load duty cycle. Imco has a beefier solution but $$$. I used to carry a spare XR in my pickup toolbox just to finish a weekend event.

Install X upper gear set. Half the price of XR gear set

Actually sounds average or better then many actually!

Just Drive your performance offshore boat like it's made to be driven....and enjoy it! or get a pontoon....driving like a grandma does minimal to nothing to increase the life of a bravo drive with over 400hp going thru it. Now don't confuse that with abusing and not maintaining.

Definitely plan on freshening evey year or two as early as 20-30hrs depending what the magnets show.

Or upgrade drives

100 hours is pretty good, 353 is a stout boat, 600 merc hp is same as 625-650 hp if comparing to any small shops dyno, so boat is going to eat bravos every 100 hrs. Are you running 5 blades,it accelerates bravo failures too.
Run heavy synthetic amsoil as suggested, it may stretch out the rebuild intervals. In general bravos fail because of many things:
A bearing starts to fail from high speed/rpm use prob caused by lube failure/temp/viscosity breakdown, this allows gear or shaft to run misaligned, gear teeth fail
Over loaded, ie heavy boat, 5 blade props, too much tq, lube is literally squeesed out from between the itty, bitty gear teeth, chews up, if let go long enough pieces get wedged thru teeth or metal gets in bearings then gears try to spread apart blowing housing apart or catastrophic failure
Catastrophic instant failure- too much tq/hp vs slip, at higher power levels you simply shear off a shaft or blow teeth as they are severely overloaded compounded by less prop slip ie 5 blades like maximus, etc. Water is 800 times denser than air, boat uses every last bit of power it can to get boat to its top speed. Thats why once boat is on plane babying the throttles but then holding it wide on top isnt going to increase drive life a whole lot.
Heavy duty towers, hd caps, stronger shafts, correct set up, extra oil cooling, thicker oil, will all help. In end though you still have a 10,000 lb boat with fairly torquey motors, waste 3500 to 10,000$+ every 50 to 100 hours or spend 25,000 or so once and upgrade, hard pill to swallow for sverage guy!

2 of the best things you can do is the drive showers and get the teague billet caps, its thicker and stops the flex the top caps that hurts xrs. I ran that on a much heaver 42 cig and never had problems, change drive oil every 30/35 hours, thne just runnit and enjoy it

Hi Articfriends,
Yes, I do have 5 Blade Max props, 32 pitch and I think they are too big or too much pitch. The boat feels like it is lugging when getting up on a plane (I don't use full throttle when pulling out). I am going to see my prop guy next week. Should I get 4 blades or see if he can reduce the pitch on the 5 blade props?
You spoke of spending $25K for new drives, what drive would these be? Impco?
Thanks,
David

IMCO SCX upper and lower drives are GREAT. Gain strength but lose 2-3 mph. continue to run less expensive 5 blade.

Arneson ASD7 are a proven upgrade for your haul. Gain strength and gain speed! More work to install then a standard SCX and more expensive props, but a better value then a SCX-4.

Those are the only two cost effective options. I would not recommend any other upgraded drive that still utilizes XR gears. And if your going to swing offshore style props the Arneson is a much better option over the SCX-4.

Or buy a spare set of XR drives and swap out when your break if your worried about down time

I personally would not waste a dime upgrading any Bravo based drive because they will still break and prematurely wear out no matter what

Thats kind of where I am. Sometimes they last and sometimes they dont. I just buy spares when I see them on craigslist. Now I am looking for X uppers. With a battery impact gun and a drive jack I can change out a drive by myself with Nascar pit crew efficiency in 20-30 minutes including getting all the tie bar stuff back on.

I dont know if I should be proud of this....

How do you feel about Mercury Speed 6s? I'm thinking old tech and hard to get parts. Is this correct?

I'm building a Donzi 22 that I'm shooting for a balance between speed/power and showy. Planning on putting 800 to 950HP BB in it. Only thing original at the end will be the fiberglass.

A 22 donzi with 950hp and a SSM6...:bong::bong::fear: I doubt the boat is bouyant enough for that weight

Save thousands of dollars and time...
Drive Guardians
4 Blade props

http://www.cpperformance.com/p-80007...ian-bravo.aspx

38TG here with 500efi's currently have a little over 300 hrs on standard xr's. only had one lower failure in 4 years. Knock on wood. All in all not bad. Probably gonna rebuild them next year. Maintenance is key. Every 20 hours oil change. And don't beat the crap out of them.

Oh I'd say a #6 drive will take 950 HP with no problem. I'm just wondering where you're going to sit in a 22 Donzi to drive it. By the time you add the transmission and new stringers/ cross members to mount the motor in its new (further forward) location, you'll be sitting on top of the bow light. A Donzi 22 can be one evil handling boat with much less power than you're talking about.

You may be correct in that "Only thing original at the end will be the fiberglass." It may end up being fiberglass shards though. Be careful.

100 hours might be all you get out of XRs behind 600s. Its a pretty heavy boat and the 600s are harder on the drives than say a 525 because of the blower, it makes a lot of torque down low and carries it through the rpm band more than a N/A motor. 4 blade props will help because they tend to slip more, but will be slower in the midrange. I would say just take care of the drives, change the fluid often, and check the magnets even more often.

Ultimately I would upgrade to SCXs, then that also leaves the door open for the Whipple upgrades on those 600s, you could easily make 850 per side and that still won't stress the SCXs. Sell the XRs to offset the cost a little bit. The Arnesons have had good results on Formulas and would be the ultimate solution, but the motors have to come out to install them and you would be running much more expensive (albeit efficient) props.

Just because I'm putting 800 to 950 HP doesn't mean I'm going to use them all. I'm not building a practical racing boat. Consider it a 23 T bucket on the water. It's just for fun and kicks and giggles.
Just because the motor is capable of 800+ HP, doesn't mean the engine will weigh substantially more. I think we've all seen the guy from Sweden's 22 that does 112mph with a Dart 540 and Procharger. I'm guessing his HP around 800.
That said, I am beefing up the stringers. Why does the motor need to move forward?

If you don't know why the motor needs to come forward, you may want to stop while you're ahead:cartman::party-smiley-004:

Really? This is your advise? I thought this part of the site was about supporting mutual boating interests. Helping, good, qualified advise. I voids you come out of the womb knowing everything about boating? I've been a recreational boater all my life. Been a hotrod enthusiast all my life. Spent a great deal of my adult life painting cars, building dozens of kick ass show quality hotrods. This is my fist attempt of building a hotrod boat. I'll be learning a lot. That's why I've asked for help before diving in.
Thanks for your smart ass advise!

Understand your frustration.

The reason it needs to come forward is because the 6 drive requires a transmission unlike a standard bravo that would normally come on that boat. I would say stay with a beefier bravo style drive. No need for a 6. As stated before- the 6 weighs a ton. Heck they can't even go on a 30 skater. Your boat will not be very heavy. Which is another contributor to bravo drive failures.

Thank you so much! This is the info I need. I do have a new XR with Imco lower. These are what's on my 35' fountain. I know the Speed 6s can handle more HP that's why I asked.
Again, thanks so much!!

You are very welcome:lolhit:


Btw, go research the donzi section here or donzis.net to learn about the 22 before you go kill yourself. That boat runs very well with mild power. Don't want to see you end up like the gentleman at this years shootout in a 22 Donzi

Ps. Get ready for plenty of ball busting... :daz:Tough crowd around here during winter time. Helpful nonetheless if you can take a humble approach :thankyouthankyou:

Great option for rough water applications, or in addition to an upgraded drive.

NOT the answer to the bravo blues though.....

Let's face it all- Bravo is a bad 5 letter word in our world! Lol

Getting back on topic of the original post. You caught the wear before catastrophic failure that is great. Time will tell next season, I am involved in a similar project. Boat is 40 V-hull, power is Teague 825, drives are Teague Platnum - very similar to Bravo XR. We are rebuilding both drives with all new internal components and installing Marine Design Corporation, Drive Guardians. I highly recommend you call them and call the references of race teams and customers they have. It is my belief that the gear face damage is done by torque spikes that are not always detected by the driver. You have established the existing life cycle to be 100 hours. The cost of the Drive Guardian will be absorbed if you double the life of the gears. All the options are expensive but eliminating the torque spikes make the most sense to me. At a minimum it will help reliability and give you a peace of mind running in rough water or aggressive speed situations. The Teague top cap is definately and improvement over Mercruiser, other than that the upper case is the weak link. I feel this is why the IMCO SC upper is better, the case is steel thus stronger, the gears are the same. Be sure to inspect the lower gears carefully. They carry the torque multiplied load because the upper gears increase the torque. The upper gears are more prone to metal to metal contact due to impact loading of the gear faces and the higher oil temps. The lower gear set case is usually in the water and the oil stays cooler and protects face impact better. These are just my opinions based on the gear wear and failure I have found. I'm hoping the drive guardian technology proves to extend the life of Bravo drives.

It is donzi.net

Thank you to all who have given helpful comments. I have passed this info on to my mechanic and we will certainly use it.
Dave

Yes, if Imco scx's cost you 12.500$ each you will be into about 25,000, keep in mind IF you do it while your old drives are still working you can offset some cost by selling them off. That tq lugging with 5 b;ade maximus props puts alot of strain on shafts/gears etc, thats why I mentioned Maximus 5 blades. I ran well over 1000 hp and ft lbs of tq in my single engine 272 Baja for years, ran all the max worx billet shafts etc, installed a stellings box at one point back when I had only 950 hp, thought boat needed more blades on prop, tried a maximus 28 pitch and almost immediately sheared off a billet max worx prop shaft, went back to the 4 blade labbed props and ran even more hp without shearing shafts instantly

Has anyone thought of or switched to Arneson surface drives? I've researched the costs and there slightly more money than complete SCX upper, SC lower, trans some assembly, helmet, etc but it appears to have some cool benefited. Less Maintanance, less parts, slightly high top speeds (maybe 3 to 8mph from what I've read)? Anyone know?

Artic, whats your take on X gears versus XR gears?

Wow, that picture of the sheared off shaft is amazing. The strain on the parts must be just unbelievable.
I dropped my props off today at the prop shop and he said that he is going to cut down the blade surface area to get my max RPM up from 4,800 that it currently is to 5,200 as recomended by Mercruiser.

With regard to the 5 blade Maximus's... Would be interested in your all's thoughts when talking about smaller/lighter boats. (E.g. 24/25 foot boats). Less wear/strain on the XR drivetrain is what common sense would tell me... but maybe I am wrong?

I have a 2016 Hustler Talon 25 (~3300/3400 lbs) with a 565, ITS, and XR drive with 5 blade Maximus. Absolutely a rocket ship and love it, but only have 24 hours on her, so now now wondering if it's only a matter of time. 😳 Have already changed fluid twice... everything appears to be in check.

Dean

Dang I'd like to see pictures of your boat. Didn't even know they were still being produced

See if this link works for Hustler's web page.

https://hustlerpowerboats.wordpress.com/page/2/

as far as the 22 donzi - it was designed way before the bravo drive existed - and that ALL pre-bravo 22's with BBC's came with a left hand TRS drive and transmission (except a few 87's w/ 330hp alpha combo) - there is room even for the longer borg warner trans. But you will find that 600hp with a bravo will be a lot more fun to build and maintain than 800hp and a #6. The trans and number six will probably cost you 10mph at the same power. 525hp and a bravo with slightly higher than stock X dimension will get you to 80mph. 700 should get you into the 90's, and might not break drives because the hull is so light.. 800hp? Get a better hull design since the stability of the rounded keel isn't much fun at higher speeds, and welcome to broken drives. Pretty sure you'll have to cut into the rear seat bulkhead for the snout of a large blower with a trans setup, no so if you stay small like a 250 or less with their narrower drive belts. :)

Dean,
What pitch Maximus and what rpms can you pull with it? We tried one on our 26 AO (same bottom I believe) and the boat didn't like it. Maybe the prop we tried had too much pitch. We now run 32 and 34 non labbed Bravo props. You're right these little boats are rocket ships, fun to say the least!
Rob