Removing the Prop Shaft from a model 402 Mercury 1970 40 hp

I am trying to remove the prop shaft on an mid 70's 40 HP Mercury, the manual said to

"remove the locking ring, (done) now place the prop shaft in a vice, tap gear housing mid-way between the anti-cavitionion plate and bearing carrier while pulling housing off prop shaft"

I have tried this, plus have put heat to it, if anyone has a goood way to get it out, I would live to hear it.

Re: Removing the Prop Shaft from a model 402 Mercury

Sounds like you have a step missing there.

With the locking ring removed you next have to pull the bearing carrier. It can be taken out with a slide hammer (over-kill in my opinion) or a bearing puller (you pull the carrier off the prop shaft). Then with the carrier removed the reverse gear will slide off. Then you can undo the pinion gear and remove it THEN you clamp the propshaft and tap the case off of it.

You will never get anything to move by clamping the propshaft and tapping on the case as long as the pinion is in place. You need to remove the carrier first with the propshaft "in place".

Re: Removing the Prop Shaft from a model 402 Mercury

Are we absolutely sure that the pinion has to come out before the propshaft will come out ?????

Re: Removing the Prop Shaft from a model 402 Mercury

The propshaft should pull out with the pinion in place, but the pinion has to come out to pull the forward gear. Additionally, if the pinion gets damaged, then the forward gear must also be replaced (they work as a matched pair). So anytime I'm "bangin'" on a gear case to get things to come apart I prefer not to have the clutch dog in close enough proximity to the pinion that it could inadvertantly cause some damage to the teeth.

If all the guts are being replaced I am less concerned, but if you are trying to re-use what can be "very expensive parts", I tend to work a little more carefully than even the manuals suggest...

Re: Removing the Prop Shaft from a model 402 Mercury

So to answer the original posters question---------------------The propshaft and bearing carrier can be pulled out as he was trying to do it.--------------------Corrosion may be holding it from coming apart easily as it would on a fresh water motor.

Re: Removing the Prop Shaft from a model 402 Mercury

Again, the answer is "maybe". He is referring to the instructions from an "aftermarket" manual (Seloc's) which states as "step 10" to clamp the propeller shaft, after the retainer is removed, and tap to remove the entire shebang. It then goes on to state that if it's "frozen" that you should attach a slide hammer to the end of the propshaft and otherwise strongly convince it to separate.

That process which effectively slams the clutch dog into the reverse gear which then hits the bearing carrier is NOT the process in Merc's own manual which states that after the retainer is removed you pull the bearing carrier with a gear puller, then remove the reverse gear and pinion before further disassembly.

The Seloc's method may work fine when the motor is only a couple years old or if the case has been "cracked" every few years to replace seals, but on a model that is over 30 years old, perhaps the OEM method is the way to go...

Re: Removing the Prop Shaft from a model 402 Mercury

Mercury manual 90-68647 also states to do the same thing as the Aftermarker manual. The question is has anyone come up with a better way to get it off?
Thanks
Oliver

Re: Removing the Prop Shaft from a model 402 Mercury

It is being held by corrosion I assume --------------------so how to get it off is a guess, it may take some brute force.

been heating and beating, guess I will keep that up. Was just hoping someone had a better Idea.

Submerge it in a drum of diesel or kerosene for a couple of days,or even burnt engine oil,very messy though

You have the "puller" you need sitting right there: the propeller! Put it back on the shaft part way, with some thin plywood between it and the housing on BOTH sides. Next, screw the prop nut back on, using a stack of washers to keep the nut in the range of available threads. The prop shaft assembly will come right out and no damage will be done--UNLESS it's major league corroded in place. Overnight soaking with penetrating oil is the ticket here. Position the LU with the prop shaft vertical and soak it with your best penetrating oil once an hour all evening. Then go to the "puller".

Jeff

Outstanding Idea, will soak it tomorrow and try the prop removal Monday.
will let you know how it works...

Sorry to bring back an old thread but we are having the exact same issue with getting the propeller off, did anyone ever find a solution?

Yup; heat the prop hub with an acetylene torch while prying it off with a screw driver. (Shoot the heat inside the prop from the rear to heat up the inner part of the prop hub.) With the outer part of the prop off, cut the rubber away and heat the inner hub with the torch. It should come right off.

Jeff