Trouble aligning Bravo XR upper gear timing marks
#1
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Trouble aligning Bravo XR upper gear timing marks
I bought some used Bravo XR drives. I disassembled the upper to inspect gears, bearings and bearing race on tower. All looks good. Trying to reassemble, but having trouble keeping the +/- timing marks aligned on center after installing universal. I set the marks on center with the bottom gear showing the "+" and the upper gear showing the "-". but after tightening the retaining nut they are no longer aligned on center. I'm confused because the amount it's off by looks like less than a tooth off. How can this be?? I've tried and retried several times with the same result. Time for some expert help. I enjoy doing my own work, but don't want to screw it up. Do the marks need to be exactly on center after assembly? Any Bravo mechanic out there want to become my new best friend? Thx for the help.
#2
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Sounds like you are just rotating the input shaft slightly during the assembly. The gears rotate in opposite directions so they have to line back up with rotation. Your doing the assembly correctly.
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I have the same thing happen to about 50% of XRs that I build.
Sometimes I will clock the pinion gear a quarter of a turn and give a look.
If you are sure that you are not a full tooth off then run it.
hope this helps Mac
Sometimes I will clock the pinion gear a quarter of a turn and give a look.
If you are sure that you are not a full tooth off then run it.
hope this helps Mac
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Thx for the reply. That's the point I'm at. just run it. It's not off by a full tooth so it seems to be an impossible task to keep the timing marks lined up since the drive gear must mesh with both upper and lower driven gears. Thx again for the help. I really appreciate it.
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Try counting the teeth on the two gears, I have come across a couple of used upper that had different gears in them. These units the marks would not quite line up and when rotated they would only come close to lining up every other turn in a half. The funny part there was no problem with running there were just leaking.
#7
Charter Member #601
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Very common for them to not line up perfectly. Sometimes I will spin both gears and use the +/- instead of the -/+ and they seem to get a little closer. You can check to see if it is an issue by fully assemble with back cap and turn the input shaft and see if you can feel an tight spots. Check Fwd, Rev, and Neutral. There shouldn't be any tight spots. If you notice on the + mark there is an H looking stamp in the ring. I believe that is a bit of tolerance for the way merc makes the fine XR gears that are usually not round, etc.
Just my .02...
Just my .02...
#8
Geronimo36
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I've had a few that I built don't line up perfectly either but have never caused a problem. That bump ring is not an exact science. It just marks perceived high and low spots on the ring.