Wanted: Broken/Pitted/Spalled/Worn Bravo XR Upper Gears
#1
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Joined: Oct 2013
Posts: 140
Likes: 15
From: Chesterfield Twp., MI
I'm interested in doing some failure analysis on Bravo XR upper gears.
If anyone has some parts they've replaced as a result of a failure or preventative maintenance, please PM me. I'll pay for shipping.
If anyone has some parts they've replaced as a result of a failure or preventative maintenance, please PM me. I'll pay for shipping.
#2
Gold Member

Joined: Jan 2002
Posts: 703
Likes: 27
From: Southern, IL.
I just rebuilt/ overhauled 2 XR drives for different customers,, both have badly worn/pitted/damaged upper Pinion gears, but the driven gears looked great,,,
I checked the specs. on both before teardown,, such as backlash on driven gears, pinion gear depth, both had pinion gear depth too deep, ,driven gear backlash was way too loose,, and the rolling torque was '0' on the pinion bearings,, both were previously rebuilt by some other shop. Not blaming anyone, possibly they worn down to these tolerances, but not the pinion depth, ,who knows.,
I checked the specs. on both before teardown,, such as backlash on driven gears, pinion gear depth, both had pinion gear depth too deep, ,driven gear backlash was way too loose,, and the rolling torque was '0' on the pinion bearings,, both were previously rebuilt by some other shop. Not blaming anyone, possibly they worn down to these tolerances, but not the pinion depth, ,who knows.,
#3
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Joined: Apr 2014
Posts: 273
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From: Lake Ozark, MO
Damn, just threw all my gears in the trash last September... gears from my IMCO upper which my understanding are the exact same gears as the XR. I can give you the failure analysis though, my lower ate itself and all the metal shavings went upstairs to visit. Drive seized up with the shifter stuck in forward.
#4
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Joined: Nov 2002
Posts: 4,181
Likes: 334
From: ankeny,ia.
I sent 47 #'s worth of the to BUP last year and he had them analyzed by a gear guru and as I recall, the issue with them was the heat...maybe he'll chime in on this...I've yet to accumulate any more, but chances are I'll see some this summer.
#7
Sub'd, I've got Imco Xtream SCs w a little over 50hrs, no signs of trouble yet but I'm interested in the subject and when mine are ready if your still around I'd be happy to send some reminents your way. Could you please post findings, theories, etc? I know the subject has been covered but it'd be nice to read some more. Like what people got for hrs with what lube and what damage. Course, 10 billion variables too soooooo?
#8
Banned
Joined: Jul 2011
Posts: 9,594
Likes: 46
From: Ft. Worth TX
Actual gear manu took my gears. 2 main names I keep getting for me to go hire from all the gear manu's. These were the 2 top persons in the field. There was a lot of testing done and a big 10 page report about all of it.
Many problems were found. Lack of lube as to how they get their lube, heat another big concern. Stress. and the materials about average at best and the processing of it, including heat treating. And the list goes on and on. They also said the gear oil used 4 sure could not handle its job. Short jist of it.
Very interesting as I learned a lot about gears and the manu processes. I will be heading back this year to see about anything new and further my education about gears and failures. To improve upon marine drives and internal components - I personally do not have the money to invest nor currently the time. It can be done 4 sure but one needs some up front money that could afford.
I was thinking about trying to get some money backing for this - but I know how that will go, my time and money will be wasted. Heck I could not even get 10 boat people up here to buy into a Diacom scan tool at a tad discount rate on top of.
Many problems were found. Lack of lube as to how they get their lube, heat another big concern. Stress. and the materials about average at best and the processing of it, including heat treating. And the list goes on and on. They also said the gear oil used 4 sure could not handle its job. Short jist of it.
Very interesting as I learned a lot about gears and the manu processes. I will be heading back this year to see about anything new and further my education about gears and failures. To improve upon marine drives and internal components - I personally do not have the money to invest nor currently the time. It can be done 4 sure but one needs some up front money that could afford.
I was thinking about trying to get some money backing for this - but I know how that will go, my time and money will be wasted. Heck I could not even get 10 boat people up here to buy into a Diacom scan tool at a tad discount rate on top of.
Last edited by BUP; 06-04-2017 at 12:45 PM.
#9
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Joined: Oct 2013
Posts: 140
Likes: 15
From: Chesterfield Twp., MI
At this point, a direction to try is clear. The technology exists to extend the fatigue life of the gears, it's only a question of how much investment it will take to bring a solution to market, and how many thousands of sets the market will support.
Still looking for a set of XR upper gears. Will pay for shipping.
Still looking for a set of XR upper gears. Will pay for shipping.



