Blowing Drives?
07-30-2012 | 01:09 PM
#1
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Joined: Jun 2005
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From: Bay City, MI
Blowing Drives?
Last summer i hit a rock and broke my XR. I got a used XR upper and got an IMCO 2" shorty. I had my mechanic go through both upper and lower and new bearings and such, said both gear sets were like new. I also put in a new vertical shaft. After I got my drive together I threw a rod on a new engine build (warranty job at least). So with the new drive last year I maybe ran 20 hours. Now i got my boat back with the new motor and the upper gear set broke while I was breaking in the new motor (less than 2 hours of run time). Took out the lower gear set to but my cases and shafts are all ok. So, i borrow a friends Standard Bravo 1 to get a little run time on the new engine. after about 4 hours of running I now have a vibration in the drive and a thumping noise when in forward. No clunks or loud bangs and goes in and out of gear fine and doesn’t make any noise when in reverse, only forward? 2 drives in 5 hours since engine was out, could motor mounts not be aligned correctly? I do not have alignment tool to check yet but was curious if there was any correlation with these drive issues and the engine in and out? Also, this is now 2 XR's that have failed and was curious if i run a stock Bravo upper with the IMCO shortie and my new vertical shaft? My engine is procharged to right around 700 hp and i think I’m gonna take the charger off and back it down to the high 500's with torque around the same and naturally asperated so I can run without breaking drives. THANKS for any advice fellas, this has been a very frustrating process...
Last edited by wieland77; 07-30-2012 at 01:32 PM.
07-30-2012 | 07:53 PM
#2
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Joined: Aug 2005
Posts: 6,306
Likes: 1
From: Between A Womans Leggs in IL
fixx
Last summer i hit a rock and broke my XR. I got a used XR upper and got an IMCO 2" shorty. I had my mechanic go through both upper and lower and new bearings and such, said both gear sets were like new. I also put in a new vertical shaft. After I got my drive together I threw a rod on a new engine build (warranty job at least). So with the new drive last year I maybe ran 20 hours. Now i got my boat back with the new motor and the upper gear set broke while I was breaking in the new motor (less than 2 hours of run time). Took out the lower gear set to but my cases and shafts are all ok. So, i borrow a friends Standard Bravo 1 to get a little run time on the new engine. after about 4 hours of running I now have a vibration in the drive and a thumping noise when in forward. No clunks or loud bangs and goes in and out of gear fine and doesn’t make any noise when in reverse, only forward? 2 drives in 5 hours since engine was out, could motor mounts not be aligned correctly? I do not have alignment tool to check yet but was curious if there was any correlation with these drive issues and the engine in and out? Also, this is now 2 XR's that have failed and was curious if i run a stock Bravo upper with the IMCO shortie and my new vertical shaft? My engine is procharged to right around 700 hp and i think I’m gonna take the charger off and back it down to the high 500's with torque around the same and naturally asperated so I can run without breaking drives. THANKS for any advice fellas, this has been a very frustrating process...
07-30-2012 | 09:57 PM
#3
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Joined: Sep 2003
Posts: 242
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From: michigan
You should be able to run a pro charged 700 hp engine with no problem on an xr drive if you are reasonable with it and the drive is setup correctly. I have several customers running more hp than that with no catastrophic failures. Setup and internal components is the key to longevity with the xr based drives. Feel free to call me with questions at 989-464-5531. Rob
