Who's blown an outdrive??
 

Over the years I've blown a few outdrives usually due to overpowering or aggressive driving. But recently I've blown 2 XR lowers one 1.36 and one 1.5 ratio. Both times the lower gears were the problem. This is unusual by my past experience. So the question is- Has anyone else been breaking teeth on their lower rather that shafts or teeth in the upper?

Re: Who's blown an outdrive??
 

Dave,
Did you get the motor back together? Are you breaking XR drives with the Quad rotor or your old blower motor?

Re: Who's blown an outdrive??
 

I lost my lower gears due to a bent prop shaft. The slight bend was nothing you could see by eye but when put in a lathe I could see the woble. Can also be from running on a damage or improperly balanced prop under high rpms and hp applications it doesn't take much to cause damaging vibration.

Re: Who's blown an outdrive??
 

I picked up the boat today with the Quad rotor. We blew the XR this morning while testing. Jason is going to put the 1.5 gears in the sportmaster XR lower since I must be rebuilt. The Bmax is in FL for repair right now. My boat is becoming a trailer queen...

Re: Who's blown an outdrive??
 

I was thinking the prop could be an issue. Since I have had this happen on two different drives. The prop is a brand new bravo 1, but it could be out of balance, I have not noticed any vibration.

Re: Who's blown an outdrive??
 

You guys got that back together rather quickly. I hope it works better this time around. I don't think you can expect an XR to hold up to the kind of power you are putting through it, but I am sure you know that.

Re: Who's blown an outdrive??
 

You might want to talk to someone at Imco or Teague. It's my understanding that these HP guys do NOT want Merc oil in the highly stressed units. Try Amsoil or Redline, but don't take my word for it---call the pros who build the HI-perf stuff AND warranty it. --- JP

Re: Who's blown an outdrive??
 

The folks at Konrad recommend Royal Purple. They found it to work the best in their drives.

Re: Who's blown an outdrive??
 

I have broken xr upper gears. last time i sheared max machine worx vertical shaft vertical shaft. The lower gears are always scalloped or scarred where they had to be replaced but thev'e never outright failed on me,Smitty

Re: Who's blown an outdrive??
 

I have come very close to blowing my XR's because of the pinion gears---word has it that Merc had a soft batch come through around the time when they first came out. I was running these XR's in a 32' A/T (8000 lbs) with 540 inch 650+hp. We caught the gears in time after about 50 hours of use.

ZT260, Could you please tell us what kind of power you are putting to your XR's and what size boat you are running it all in? thanks

Smitty, that is the first time I have heard a Max Machine Worx verticle shaft break---not that they haven't ever before, but I just haven't heard of any and haven't heard much bad about their stuff. What kind of power and what kind of boat, and how many hours on the drives when this happened? thanks

Re: Who's blown an outdrive??
 

At the boost I was running about 1000HP, Now I know thats too much for standard XR's, but I have a BMAX and the same happened to the lower gears. I drive very carefully, not to break anything. But this is unusual, I would think the upper gears would let go first.

BTW it's a 26' single Vhull about 4500 pounds.

Re: Who's blown an outdrive??
 

Kaama,i have a baja 272,turnin 30 pitch 4 blade around 5400-5600 rpm's.Powered by 540 w/m-3 procharger,8-10 psi boost. The shaft had roughly 160 hours on it,i stand on throttle coming on plane occasionaly and i've been airborne before under full boost on the msd at 6000 rpm's. I Respect what Jason and aaron are doing with their outdrives(the IMPOSSIBLE),and am in no way bad mouthing them. Even though there is no warranty on anything they sell they had me send the shaft back to them to have analyzed and gave me 1/2 off on a new one, i am a dealer for them(they give me 10 % off on everything) and i put my own drive together with their parts. The strange thing was the shaft broke in the largest section and i was running there standard dia billet prop shaft(it should have broke first). Iv'e been amazed that these things hold together as well as they do,Smitty
When the drive broke this time i ordered another complete one from them while i fixed the old one,the old ones back on the boat and i have the low hour new one for a spare!

Re: Who's blown an outdrive??
 

I blew my XR lower pinion into pieces parts at 100hrs. Shredded the entire drive top to bottom. Always been very gentle getting on plane and moving the throttle. 700hp is apparently too much to go much past 100hrs. Will have it torn down now every 50 hrs for inspection and gear replacements to try and save redoing the entire drive.

Re: Who's blown an outdrive??
 

Blew an engine coupler, u-joint and upper gears... The busted u-joint put a nice dent in the case. The shop is still working on the estimate.b

Re: Who's blown an outdrive??
 

Zahndok has a REAL good idea,last time my outdrive broke (was the lower vert shaft w/approx 160 hours i mentioned earlier in this thread) the upper xr gears had somewhere around 90-100 hours and the pinion gear had about a .005 thou scallop on the teeth on the load side. I replaced it but the other two gears had no wear pattern at all.I was able to buy just the pinion gear from max machine (they do enough drive work that they could seperate a set). If shaft hadn't broke, the pinion gear probably would have within 20 more hours,so maybe tearing the drive down in hi load apps and discarding gears and bearings as a preventative measure might be a good idea,Smitty
I can see the E-bay ads already:For sale:xr gears, like new,never abused,AS IS,Cheap!!

Re: Who's blown an outdrive??
 

articsmitty,

Thanks for the info---you still haven't mention how much power you are making with your engine, but I would guess somewhere between 900-1000+hp. I was curious about the Max Machine hardware because I have purchased some XR size, prop shafts, -2 inch verticle shafts and clutch shafts. I wasn't able to get my boat in the water this past summer so I have not been able to use there stuff yet. I've only got about 65 hours total on my drives thus far and only 15hrs since I replaced the new pinion gears.

I have had "Mr. Gadgets" do the repairs on my drives---he mics EVERYHTING and totally blueprints the drive for assembly. I will probably have him install the new Max Machine parts within two seasons from now depending on how many hours I put in on my boat until then. I have some new -2 inch IMCO shorties and next spring I will be having him install thoses. Out of all the aftermarket Bravo drives parts manufacturers, Max Machine is one that I have heard of the least amount of problems---but then I don't really know how much of their stuff is out there compared to others.

Anyway, I believe in their product so I bought it. I have a lot of water cooling action going on my drives and I choose to use Redline Shockproof drive lube.

Re: Who's blown an outdrive??
 

Kaama,i think my hp is closer to 750 but i'm not really sure. I have complete confidence that there is nobody that has superior bravo upgrades to max machine worx parts,Smitty

Re: Who's blown an outdrive??
 

Everyone has their opinion of the best drive, but I know who has the best warranty and service. The bravo shop! I sent my Bmax to FL from NY for repair. It was back in 7 Days including trucking time, and they paid for everything including shipping. This weekend I get to do some more boating rather than cutting the grass. How much is that type of service worth to performance boat owners? Thanks Dean!

Re: Who's blown an outdrive??
 

Konrad's could be sold without a warranty because it won't be needed.

..although they have a fantastic warranty.

Re: Who's blown an outdrive??
 

Like I said everyone has an opinion, but don't kid yourself, everything breaks sooner or later. Just be sure someone stands behind whatever you buy. I'm sure glad I did.

Re: Who's blown an outdrive??
 

I considered a b-max this summer but when i called dean the 4-6 wk backlog wasn't going to work for me. Zt-my understanding is a b-max has no provisions for thru prop exhaust,am i correct? I am running lightning headers w/switchable y-pipes that push exhaust thru prop when idlieng so if a guy wanted a b-max he's committed to thru hull's and reconfiguring y-pipe etc,adding mufflers etc?Smitty

Re: Who's blown an outdrive??
 

take your drive to a shop that will shim the brg. carrier instead of using the crush sleeve we do this in the shop all the time with great success

Re: Who's blown an outdrive??
 

Xtremespeed,didn't mercruiser used to do that with the early bravo's? seems like i seen the procedure for it before,do you think that the prop shaft is thrusting around then loosening up the crush sleeve resulting in gear failure due to no preload?I started rebuilding outdrives a few years ago,maybe i'll do that in the future,i use solid spacers in place of crush sleeves on ford 9inch and chevy 12 bolt rear ends for hardcore racing and it works,Smitty

Re: Who's blown an outdrive??
 

It will not go through prop, but it can go through the Y pipe and exit underwater. I did this for a week before I switched to dry pipes on the new engine. Just don't try to go past 1500rpms this way.

Re: Who's blown an outdrive??
 

Are you saying bmax uses a crush sleeve? I'm not up on the internals of the bmax.

Re: Who's blown an outdrive??
 

Just blew my drive two weeks ago at Sanduscky. Boat was running great when it blew the starboard drive doing 60. It sounded like I bottomed the boat out. It is at Monroeville Marine getting repaired. Have to replace the entire outdrive. Looked like a grenade went off in it.