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40 hp 2006 4st lower unit

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cgj357

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40 hp 4stroke efi 2006 serial 1b282213 with 2.0 :1 gears Buddy hit stump and broke pinion gear. Tried to install gear without pulling shaft could not. Tried to pull the water pump base and the pulling ears broke out and would not move. How can I remove this and where can I get a shaft holder and pinion locator to set preload on bearing?
 
What's left of the pinion is still bolted to the driveshaft. I suggest you let an expert reassemble it.

Jeff
 
Or if you would like the longer explanation which should start with, minimally, chucking 35 bucks or so for a manual and reading the process of servicing the lower unit.

Drain the lower unit of oil then remove the prop and thrust hub.

Unbolt and the bearing carrier and pull it (you will need a puller of some description - I use threaded rods and a harmonic balance puller - cheaper than the "Merc tool".

Remove, at least, the reverse gear and the propshaft (otherwise you won't have the clearance you need to get the pinion off).

Although, if you do have a busted pinion I would want to get a look at "all the guts".

Get the special socket to place on the top of the driveshaft (only sure way not to chew things up - and I have tried numerous methods).

Using the special socket to hold the driveshaft steady (sell for about 30 or 40 bucks and fit on a ratchet), work a boxed wrench over the nut at the bottom of the pinion and undo it.

Replace any parts that look suspect and since you have everything out, re-doing the carrier seals is worthwhile. Again, if the pinion is really toasted you may have chewed up one or both of the gears. For many years they gears had to be replaced as a set, I don't know on this particular model whether or not you could get away with "only" replacing a pinion, rear or forward gear alone - failing to replace at least the pinion and forward, on some models, results in chewing up the new gear plus the old one because they are "not matched" (a decent manual will normally tell you the requirements).

Also, since you were prying at the water pump base you may want to have a good look at the seals and bearing "under" the water pump base that support/seal the drive shaft.

Reverse the process and torque the pinion to spec (sorry, don't have the torque for that model year). It's achieved by using a torque wrench to put the correct torque on the drive shaft using the (special socket).

Reinstall everything else, fill it with gear oil and cross your fingers that you did everything correct and don't have a leak somewhere.

At least if you have to tear it down "again" because of a missed step, everything moves easier and you have some experience taking it apart/re-assembling...
 
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I have removed the old gear inspected the forward and reverse bevel gears which are ok. I could not install the gear I have a manual but it does not cover the 2.0 box. The problem is the water pump base will not come out so I can pull shaft to be able to install the gear and replace seals and the tools to set the bearing preload and check shaft height. In the beginning I was hoping to just replace the gear and pressure test. Now without being able to pull the base that is another $70 some one has to have had this problem the manual shows using a screw driver and just prying the base out . Also where can I find the tools to check preload on lower bearing an shaft holding tool.
 
Assuming ALL of the pinion gear is off, here's what you have to do. (In some cases, the flushing screw has to come out before the pump base can come off.)

Clamp the driveshaft in a vise and smack the housing with a rubber hammer (or use a wooden block and regular hammer).

Jeff
 
Yes, maybe I'm missing something here.

Before you can pull the drive shaft you need to get the pinion (or whatever is left of it) off.

That still requires removing the nut that holds the pinion onto the shaft - and then removing whatever is left of the pinion.

Whether or not you have 2:1, 2.31:1 or even the older 1.83:1 gears the process of tearing down the lower unit is the same.

The pinion itself (or what was left of it) will prevent the shaft from coming out.

And I also would have gone with your first assumption and simply replaced the pinion leaving all else in place.

That could have been achieved by pulling the bearing carrier, removing the prop shaft and the "guts" save the forward gear.

Once all that was clear you can weasel the forward gear out.

Then using the driveshaft socket, hold the driveshaft (by it's top splines) and using a box wrench, remove the pinion nut and then the pinion gear.

There are some shims there to "save" (or replace). I would then reassemble and check the pinion height clearance (according to the manual).

ONLY IF, at that point the clearance was out of spec would I have gone the further step of pulling the driveshaft to correct the clearance.

Call me lazy, but if the work don't need doing I try to avoid it.

And the tools to hold the driveshaft and set the pinion height are available through any Merc dealer. As I noted earlier the special socket that works by holding the splines on the driveshaft (you need your own 3/8" or 1/2" ratchet handle depending on the exact socket you need) sell for between 30 and 40 bucks.

The driveshaft preload tool cost me just shy of 200 bucks, and that was from Sierra which was way cheaper than the OEM Merc tool at the time - but now I see it has dropped to about 140 bucks. Then you will also need the pinion guide, needed to get the clearance correct. That is currently selling for about 130 bucks.

So for the cost of tools alone, I would have simply tried to replace the pinion, leaving all else in place unless there was a reason to go further.

You may have opened a can of worms that can't be easily closed.

And this is partly why the cost of having things done at a shop sound so high. When you would need to drop maybe 350 bucks, or more, on special tools to do the job correctly, then add in all the parts, the 700 or 800 dollar quote to fix it doesn't sound so bad anymore.
 
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Graham I have not opened the can of worms yet. What I have done is removed the prop shaft ;pinion nut; and all the pieces of the pinion gear; cleaned all the parts. I then tried to install the new pinion gear. I could not do this.The gear would not go past the forward gear. I now have the correct manual and it stats to remove the gear on disassemble and install after the shaft and lower bearing on assembly. I'm missing something
 
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