I have a few bravo upper assembly questions. I have a pair of good earlier cases and a pair of used newer style thick floor gears going into them. I have read the manuals and feel that I have a good understanding of how to assemble them. I have already purchased some of the tools I need and am going to order the rest with the parts I need to get.

Question 1, this may be one for a very informed person, but I am just trying to make sure I understand. The 91-90244A1 puller/driver assembly comes with driver head 91-90773T, I know I need driver head 91-864220 to install the new bearing sleeve into my old case. And I know that the 91-862530 driver is for the new style case. So is the driver head 91-90773T that comes with the puller/driver assembly for old bearing in old case? That is the only thing I can figure out, which would mean that the driver head included with the tool is mostly obsolete since they no longer produce the old style gears. I suppose if you had a set of old gears you would need it. The manuals do not mention this, so without the service bulletin, a person could easily use the old style driver since it is part of the mentioned puller/driver kit and likely have some major issues.

Next question, this is the one that is really throwing me off, the manual does not say a thing about checking lash after it is assembled. But I have read some posts that I should be checking it. I understand ordering the correct shims, my cases are all stamped 94, so I need .054s for the new gears. Outside of checking the preload on the pinion bearings, I cannot find any written procedures on checking lash. I have talked to a few people locally that have experience doing this type of work, they all said just match the shims and all good. Is this one of those overkill deals that it is usually all ok but check for extra insurance? Or is this critical?

If anyone has any additional advise on this procedure, please let me know.

Thanks

I have another question, is it necessary to replace the bearing sleeve (on the tower and cap) with the new style, or just use the correct bearing driver to push it down .125? It is going to cost a few hundred dollars to replace the 4 total sleeves that are in perfect condition. If they are not going to change anything, I would prefer to use that cash on other upgrades

The thick floor gears use a shorter bearing race, as I recall, you have to use them to prevent them from coming into contact with the thicker gears.

When I bought the race tool, it came with both drivers, I don’t recall the #s
but you got to get the shorter race down deeper on the tower ( whichever of the 2 heads do that is what you need)

The thick floor gears use .030 thinner thrust races l, if the case is stamped
94 use. .064

Up til the OW s/n ( around 05, right before the slope backs came out)nothing was ever mentioned about shimming
and back lash, then came the shimmable pinion bearing setup, which you can use in the older cases, along with this is a pinion depth tool, you aim to set the
depth to .035”, also at this time, they came out with tools for checking/ setting
backlash, this consist of a tool that clamps on to the clutch cup on the gear
and a dummy input shaft and a glorified hose clamp with a tab on it to measure backlash of the pinion, while holding the driven gear.

I found that the X/Xr u joints were basically the same diameter as the drive gear, so I would just measure at the bearing cap instead of rigging up the special tool arrangement.

The vast majority of these what I did were XR’s ( due to their tremendous longevity (roll eyes) and the spec for those were .009-.015”. you change the driven gear thrust races to get the backlash desired.

Does it matter?….hard to say, they made them 17 years without doing so,
but once they changed them, I started doing them the new way, just
so so you know where you stand with them.

The service bulletin 2001-17 is saying that the shims are .040 thinner, am I reading this wrong? I have seen others say .030 also

As far as checking lash, as I stated above, the manual does not say you need to, but I have read many folks say it is needed. Hence the confusion. Unless told I need to, I am going to assemble it according to the manual with the correct shims and call it good.

I believe I have purchased every needed tool or already had them to complete this task. Along with all of the parts needed. I should have 2 complete upper units assembled when I am done, while spending likely half of what the local shop would have charged to assemble 1 of these, assuming I am successful this, is a win. New skill set and new tools

Now that I am done there until parts show up, I am trying to figure out if I can do lowers. They seem to take more attention on measurements and a few more tools. I need to swap some vertical shafts in my B3 lowers. The existing shafts have been twisted longer than I have been running them, which has been years and behind moderate power on a 38 footer. I have a pair of the thicker shafts laying on the bench that I want to swap in. I also have a B1 that I need to swap good internals into a newer case. I am assuming a vertical shaft swap could require re-shimming?

They make a pinion height tool for the lower also, but in all actually, you’re
shimming for the case irregularities, you would probably be ok using the existing shims that are under the bottom race, if all you are doing is replacing the vertical shaft.

On the vertical shaft, everything ( setup wise) is done up top,
the bottom bearing position sets the pinion height, the shims that go atop the
top bearing race set the preload, there’s a clamping fixture for this too,
I would be more worried about getting that right.

I’ve broken a vertical shaft and a propshaft and neither were as time consuming as setting up the upper, same with replacing the lower gears,
which I probably did 2 or 3 sets….but it is the garbage XR upper gears that
I spent most of the time with.

I never had a drive problem til I bought a boat with XR drives,
I bought the tools out of necessity.

Several friends started buying boats with XR drives, and they all had the same luck with them, needless to say, the tools have more than paid for themselves

That is great info! I appreciate it, allot. I have been dragging my feet on learning drives for years, allot of people have discouraged me over the years saying that they are very hard to learn. I heard that with engines also, but I have built every engine in my boats and hot rods for the last 25 years. I love learning new skill sets! And I love being able to repair things on on the fly. I blew a drive coupler at LOTO shootout week last year. Long story short, the next day we were back on the water thanks to a tree branch at the public ramp, a chain fall and other mechanically inclined friends, LOL.

Let me know when you are ready to do this. I will bring Eddie over, as he has done many. That way we can both learn.

Not a bad idea. I am waiting on parts to show up at the moment. An experienced person never hurts! I will let you know