Bravo 3 drive install?

T

Tri County Trail

Active Member
Aug 29, 2021
131
Boat Info
2005 Rinker 360
Engines
Mercruiser 8.1l Bravo 3s
Trying to reinstall bravo 3 Drive into transom. Alignment is good. I checked it with the bar. Something is holding it from going into the splines can get it into about half inche from studs rotate shaft but it won't engage and slide the rest of the way in. Going back in the morning taking a floor jack so I can fine tune the height. Have someone else helping me but looking for suggestions or hints from experienced people. Thanks for any help.
 
Did you just install a new gimbal bearing?
 
Did you have any issues getting the bearing to fully seat?

Did you use the alignment bar with a bearing ring on it to instal?
 
Okay, bear with me a bit

yes the tool will go in “fine” after the bearing is “seated” but in fact the bearing may not be fully seated. And you may have dinged the end of the splines slightly.

This can happen two ways
1 the alpha and bravos have slightly different dimensions and the right tool for a bravo needs to be used
2 it is the “right” tool but some dont have quite the right dimensions

look at the tool see if it now has any nicks on the pilot end where it gets slightly larger

look into the gimbal at the engine spline do you see any nicks around the splines

if any nicks you may need to pull the bearing and use a small file to cleanup the nicks

you can tape the file to a broom stick or big screwdriver
 
Did you tilt the bell housing slightly “up” by placing a long screwdriver or pry bar horizontally behind the lower portion of it?
 
Yes bell housing is tilted slightly with screwdriver and I will check splines
 
Tried again today the splines of the shaft are Not engaging with the coupler. Bravo 3 496 mag engine. I used my alignment tool with driver to install my gimbel bearings. I think I blurred up the coupler when driving in Gimbel bearing. I'm going to borrow a old drive shaft that has a bar welded to it, it's like an homemade alignment bar with splines. Plan is to try to get drive shaft to engage coupler and check if it will go in. Hopefully it goes in and restarts the coupler splines so original drives will go in. This is the only thing I can think of.
 
Just checking to see what you meant by "rotating the shaft". Is the drive in gear during installation? Without it in gear, turning the prop shaft to align the splines won't turn the shaft going into the coupler. Sometimes a little rotation is all it takes.
 
unsalted said:
Not sure it helps now but I just bought this jack to help me get my stern work done and it has worked well so far. $270 https://www.stumpysfabworks.com/boat-outdrive-jack.html
Click to expand...

Nice, but pricey! I just use two wooden stands I built from scrap 2x4's screwed to a mover's frame on casters. Then again, I'm on a trailer where the tongue can be raised or lowered to get the right level for the drives to slide in place.


Not my video, but used it to make my stands.
 
hughespat57 said:
Okay, bear with me a bit

yes the tool will go in “fine” after the bearing is “seated” but in fact the bearing may not be fully seated. And you may have dinged the end of the splines slightly.

This can happen two ways
1 the alpha and bravos have slightly different dimensions and the right tool for a bravo needs to be used
2 it is the “right” tool but some dont have quite the right dimensions

look at the tool see if it now has any nicks on the pilot end where it gets slightly larger

look into the gimbal at the engine spline do you see any nicks around the splines

if any nicks you may need to pull the bearing and use a small file to cleanup the nicks

you can tape the file to a broom stick or big screwdriver
Click to expand...
 
I think this is what is going on.
Gonna try to clean up leading edge of splines in coupler. The grease marks look good on alignment bar but something is off with the splines.
 
Possibly the o-rings (slightly oversize???) on the input shaft fighting you by not going in smoothly? Grease them baby's up real good. Had that one kick my a$$ a couple of times
 
It's not the o-rings drive NOT engaging splines o-rings are at least 1 inch away yet


Bill Curtis said:
Possibly the o-rings (slightly oversize???) on the input shaft fighting you by not going in smoothly? Grease them baby's up real good. Had that one kick my a$$ a couple of times
Click to expand...
 
All the years I worked professionally I never came across this. But back then you had no choice but to buy the tool from Mercruiser. I bought from an independent, came without the hole drilled for the driver.

My fault I did not clearly read the instructions and drilled the hole on the wrong side of the line I marked when I measured in the out drive. So was about a 1/4" to far from the engine. So the shaft bottomed out on the coupler before the bearing was fully seated and I nicked the coupler splines. I fought with this for four weeks on and off before I had a duhh moment.

If this turns out to be your issue be sure the bearing is fully seated it may be out a 1/16" or 1/8"
You can measure from the face of the coupler spline to the outer edge of a fully seated bearing. The critical dimension below must be less than that by 1/2" so as not to hit the splines.

To clean the splines a fairly large triangle file works best. Big enough to touch the sides but not the bottom of a spline slot.
Only need a few strokes then on each spline to clean off the bur.
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Make sure your in neutral with both shifter and drive and that the linkage that captures the shift cable protrudes from the drive with the jaws open.
 
I believe this is exactly what happened I drill my hole for my old boat and should had know better but when driving gimbal It wouldn't fully install. the bar was bouncing back funny now that I think about it. The newer Couplers with the grease fitting use the 3rd oring to hold the grease and the splines reach all the way to start of coupler. So as I drove in gimbal the alignment bar has a chamfer an to a slightly larger diameter this was what was hitting I assume. Thanks for taking the time to help out a fellow boater I really appreciate it!!!
I am borrowing a homemade alignment bar with an old drive shaft with a square bar welded to it. I will be able to check my spines with that. I will grab a couple files hopefully wont have to pull gimbal because everything is installed.
AgainThanks for taking the time to help out a fellow boater I really appreciate it!!!
hughespat57 said:
All the years I worked professionally I never came across this. But back then you had no choice but to buy the tool from Mercruiser. I bought from an independent, came without the hole drilled for the driver.

My fault I did not clearly read the instructions and drilled the hole on the wrong side of the line I marked when I measured in the out drive. So was about a 1/4" to far from the engine. So the shaft bottomed out on the coupler before the bearing was fully seated and I nicked the coupler splines. I fought with this for four weeks on and off before I had a duhh moment.

If this turns out to be your issue be sure the bearing is fully seated it may be out a 1/16" or 1/8"
You can measure from the face of the coupler spline to the outer edge of a fully seated bearing. The critical dimension below must be less than that by 1/2" so as not to hit the splines.

To clean the splines a fairly large triangle file works best. Big enough to touch the sides but not the bottom of a spline slot.
Only need a few strokes then on each spline to clean off the bur.
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