Prop Locking Question (Reverse Locking Cam?)

[Chris1956]

When was the last time you changed the gear oil? The shifting mechanisms do not usually lock up as you describe.

Dropping the gearcase will not expose any shifting cams.

 

[BB63QM]

Never…just purchased. Sounds like time to open Pandora’s box. My assumption is that I need to drop the lower unit before I can access the drive shaft area (where the reverse came lives). If the issue is in the dog clutch, that’s in the LU as well.

Do you think that it is worth changing the gear box oil alone (without actually dropping the LU)? I’m not lazy but don’t want to waste effort either, so if fresh 90W will help then that seems like a game worth playing.

 

[jimmbo]

This is a later version of your Gearcase, the Rear Bearing Carrier #63 is slightly different, as yours will have an Anti-friction Bearing Supporting the Reverse Gear while this one uses a Bushing. However it does show the Tapers on the Clutch Dog for the Forward Gear, and a plain Straight Tooth Dog for the Reverse Gear. #48 is the Shift Cam, that pushes #49, which is attached to the Clutch Dog #56, with Pin #57. #51 is what pushes the Clutch dog, out of Reverse and Neutral.

 

[BB63QM]

I see the spring, at first I though it looked like it is on the racketed side of the dog clutch so would push to reverse from the drawing, but I’m guessing it actually pushes on the shaft, cause the dog to move towards the ratcheted side, relative to the shaft (which would explain the clacking in neutral)

In any case I don’t think that this applies to my current query (how to get my LU out of reverse??). So I opened THAT question on a new post to keep the issues separate, and so that the thread title was on point, but the moderator merged it back to this thread.

Thanks.

 

[BB63QM]

Open question: How should I proceed to get the out of reverse.
1. Change the gear oil?
2. Drain/drop the L/U and inspect the Reverse locking cam on the shift shaft (another thread indicated that sometimes there is a point on the flat that if past due to over rotation, it can be difficult to return to neutral)
3. Crack open the LU and inspect the spring mentioned above to see why it is not doing its job
4. Something else?

The less I can take apart the better in my book (so far on this boat and motor, everything I open ends up needing to be overhauled or replaced)

If I do have to drop the gear case, the manual calls for a lubricant (Multipurpose Quicksilver Lubricant C-92-49588) on the splines and shaft. Does anyone know what that lubricant is? (marine grease?)

 

[jimmbo]

#48 is connected to a 2 piece Shift shaft that goes up to the Lower Engine Cowl. It does split in two, where the Gear Case separates from the Exhaust Housing/Midsection. If the two had been Separated, and weren't reconnected, or misaligned when the the Gear Case was reinstalled, all the fiddling with the Linkage up higher, won't do a thing.

Changing Gear Oil isn't going to do anything
Propshaft, Reverse Gear, and Clutch Dog can all be removed by just taking out the Rear Bearing Carrier, thought a few parts(balls and pointy things of #49) might pop out of the Propshaft.

Does your engine have Power Trim, if so, there will be no Reverse Locking Cam(on the Shift Shaft outside the Gearcase) as it is removed when Power Trim is installed

Multiple Threads on the same subject create Confusion when it comes to responding

 

[BB63QM]

Thanks. No power-trim installed.

So: if the shift shafts were/are misaligned (either from the last time things were put together or as a result of what I was doing today (trying to find reverse without the prop turning), that seems like the easiest to check (as it doesn’t require disassembling the gearbox),

Good news, since it’s locked in reverse, step one to dropping the LU is satisfied (if I recall, the process is to drop the LU in reverse, and reassemble in Forward)

 

[BB63QM]

Question Jimmbo: is there a way to know whether the two shafts are connected and aligned from viewing the parallel shafts in the Exhaust Housing, or is it necessary to unpack the LU (to view the part you are referring to above as connecting the shafts)?
(Looking at the manual, unpacking the LU doesn’t seem like a walk in the park and requires tools i might be able to borrow from the auto parts store.)

 

[jimmbo]

When you say "Unpack the LU", are you referring to dropping it, or taking it apart?
The Shift Shaft, is in front of the Exhaust housing, and actually comes down the Yoke(Steering Swivel).
Red Arrow is pointing to the Bolt that holds the Trim Tab, which covers another bolt that needs to be removed to take off the LU

 

[Chris1956]

The gearcase should not "stick" in any gear, especially reverse. I would drain the gearcase oil and refill with the correct stuff. Any marine gear oil for mechanical shift motors will work. Wallyworld usually carries it. Failing that a marine store will have some.

You will need about a qt to fill it, with about 7oz left over. Pull both plugs and let any old stuff drain for a while. Inspect the old gear oil for water and metal. Water makes the gear oil cloudy, like a chocolate milkshake. Look for steel shavings on the magnetic plug. A little is OK. Chunks that are too big for the magnet is bad.

Refill from the bottom, and when the gear oil emerges from the top plug, install the top plug and then quickly install the lower plug. A hand impact driver is a real good idea to remove and install the plugs. Gaskets on the plugs is a real good idea as well.

After that, d/c the shift cable and move the shift slider forward, and the motor should come out of reverse, at least into neutral. If it doesn't come out of reverse, you likely have serious issues inside the gearcase, maybe fatal issues.

If she goes into neutral, but not forward, it is likely that the upper shift and lower shift shafts are mis-aligned, which is a common issue.

 

[KJM]

Going back to your last 2 pic's, there looks to be a post sticking up with nothing on it and a linkage next to it with nothing in the hole on the end right next to it. Should these be attached?

 

[Chris1956]

KJM, Those are the attachment points for the shift and throttle linkages. He needs to make sure the gearcase shifts, before he installs the shift cable on that post. The design of the throttle arm assures it is in the way of any manual "exercise" of the shift mechanism, hence, it needs to be disconnected.

Just so you know, proper adjustment of the shift cable is as follows..... Manually shift the gearcase to neutral. The slider should be near the middle of it's travel, when in neutral. Adjust the shift cable barrel nut (throttle in neutral) to allow the cable to mate with the shift slide, w/o moving it.

Proper adjustment of the throttle cable is as follows..... Push the throttle closed. Adjust the throttle cable barrel nut to fit the throttle arm attachment point and add a bit of pressure pusing the throttle closed. Mercury calls it "Preload". If helps you find neutral when driving the boat, and forces the throttle to be against the throttle stop.

 

[BB63QM]

Today is a brand new day…I reconnected the shift linkage and cable and eased it forward. I thought I hit a home run, because now forward on the remote is forward on the shifter, and neutral is neutral.

But I was wrong. No matter what gear it is in, the propeller still spins counter-clockwise (reverse).

As such, I’m guessing that I am way beyond a live job as it seems that the shift shafts are not shifting anything. (I do have plenty of 90w on hand and a pump for later…new washer-seals coming later from Amazon)

Does anyone have pearls of wisdom before I drop the LU and access the shift shafts in the exhaust housing? Like what I might be looking for?

 

[BB63QM]

Well…I’m draining the LU (man does that stuff stink)…good news, no water, black as tar…bad news: plenty of metal on the magnet, and at least 1 chunck of something (something l, somewhere is broken)…

Will drop the LU and the shaft-exhaust cover and pray that I find a broken reverse locking cam (though I wouldn’t have expected a piece of that to end up inside the LU, so I’m not holding out too much hope.

Stay tuned.

 

[BB63QM]

Ok. LU is down. I took some pictures…what looks to be sand by the water pump.(pic) The reverse lock cam looks pretty scored,(pic) and dented on the side of the cam (pic) that I assume doesn’t see action (over the cliff after the plateau). Looks like the pin from above may have travelled across the lower flat (FWD), up the ramp (Neutral), roads the plateau (reverse) and fell over the edge (locked in reverse).

The female splined shaft from above seems to have taken a beating at some point (pic), but that damage is on the part that is protected by the plastic grommet, which doesn’t appear to be damaged (pic)

My guess is that such indicated the the cam is not properly aligned.

Can someone tell me what really happened, what else I need to check while I’m in here and/or what I need to do to get back into (out of) gear?

I know this much: the female spleen shaft rotates as expected in response to remote cable movement (stuck a screwdriver and there and had my wife hold and watch as I shifted)

What next?
If the next is pulling the guys out of the l
LU, what special tools do I need (repair manual calls for a Gear Housing Cover Tool and a bearing puller, bearing mandrel and adaptor, a shift shaft tool, a needle bearing driver, an oil seal driver, and a prop shaft gear tool. Real world, what do I need to borrow from O’Reilly’s?

 

[BB63QM]

Update: Aligning the reverse locking cam. Or trying at least. I can shift to reverse (turn drive shaft CW, prop shaft rotated CCW…reverse locking post pushed up by plateau on the recerse lock cam) and if I rotate the spline CW, the spring kicks in and throws the LU into FWD (CWdrive shaft-CW Prop Shaft…lock post almost off the bottom of the ramp). While there are two gear positions other than reverse (up), none are neutral (CW drive shaft, no prop movement…when lock post is on the clock between fwd and reverse, and lock postabout midway up the ramp, the prop is still turning CW with CW shaft rotation.
—-is that normal?

(how)can I achieve true neutral?
Perhaps this is where Chris1956’s new oil comes in (ie, maybe with proper lunrixation, the gearbox will better differentiate between forward and neutral)??

If that sounds right, can someone please confirm the cam position in forward, so I can get everything aligned, put back together filled up with fresh juice.

 

[Chris1956]

That cam is purely to lock the motor down in neutral and reverse. It is there to keep the motor from kicking up when you suddenly slow down or engage reverse. I would remove it until you get the gearcase straightened out. I would also pump in new gear lube before doing anything else.

Turning the shift shaft CW should shift from reverse to neutral and then to fwd. If you have something else, it is incorrect.

 

[BB63QM]

I copy that,,,I’m just using it as a reference point in terms of alignment right now (and wondering it it was the problem with the shifting, as I can see how if it was out of alignment, the cam could get over rotated and then locked in reverse but reverse lock shaft falling off the cam cliff).

I’ll stand and fill the LU today to see if doing so let’s the dog float to the middle (right not it seems to only be happy locked to one side or the other)

Can you please give me a better idea on the eventual alignment of the cam for reinstallation (where it should be relative to the reverse lock post in Rev, Neut, and Fwd (for reinstall))?

Thanks
Ps: I can’t seem to find the tool for opening the gear box (there are some out there, $40 on Amazon, but their measurements don’t seem right)..can someone point me towards the right carrier removal tool (for spinning out the multi tooth retainer, that is), or a “wrong one” that would do the trick. Just in case I need to get in there now or in the future, I need to find that tool (without buying the entire $300 set)…the rest it seems I could borrow at the auto parts store or suffer through without, but that is the key to the kingdom.

 

[Chris1956]

If you get the gears shifting, you will want to set the gearcase to neutral and the control to neutral, for reassembly. In my mind that reverse lock is optional. Just don't quickly rev up the motor in reverse, and she will stay down, well enough.

If you cannot get the gears to shift, you probably will need a used gearcase. Price out the gears and clutch dog, and you will see high prices, if you can get 'em.

Where are you located?

 

[BB63QM]

If you get the gears shifting, you will want to set the gearcase to neutral and the control to neutral, for reassembly. In my mind that reverse lock is optional. Just don't quickly rev up the motor in reverse, and she will stay down, well enough.

If you cannot get the gears to shift, you probably will need a used gearcase. Price out the gears and clutch dog, and you will see high prices, if you can get 'em.

Where are you located?

Thanks. Pleasanton,CA
Fingers crossed on getting things to shift with new lube (just waiting for shade to hit that area). I think I found the tool to open the gearbox (order 2 different ones and will send one back).
Are LUs specific to the upper, or more generic?