How best to pull shaft from flange, '08 SO 39i

[salty]

Hi folks, first post here, but thank you for years of information and assistance getting me to my first 'big' boat (an '08 SO 39i). 

My Volvo shaft seal started leaking at the end of my first summer with the boat, which was nerve-wracking of course. I've got the new part in hand and am working through installation, have the flange separated from the coupling (no problems), but releasing the shaft from the flange is giving me trouble. I got the locking nut off with little difficulty. 

Without a puller, my next step was going to be buying 4 longer bolts and putting a socket (of the wrench variety) between the transmission and drive shaft then slowly re-tightening the flange back toward the coupler, ideally popping the shaft out. From previous posts here, it's my understanding that nothing is now securing the shaft to the flange other than friction (and fate, intervening on how easy this had been to that point). In the image below, 1. is a washer pressing against the flange and 2. is the end of the shaft that I intend to isolate and push against with the socket. 



Am I missing anything here? Do I risk damaging / warping the flange or putting too much pressure on the transmission end of the coupling? 

Thanks for any help or comments!

[salty]

Or is the taper / key also preventing the shaft from moving astern from the flange? Do I need to pop the flange astern on the shaft to release the key before I'll be able to slide the shaft out? 

[Tafika II]

When I changed my seal, I had the same problem removing the flange from the shaft. I tried heating and cooling and all types of penetrating solutions, but in the end, I asked the haul-out yard manager for help. They tried a mechanical puller but broke one of the spokes. They finally removed it with a hydraulic puller. It's a pretty violent reaction. I placed a piece of plywood between the flange and transmission for protection. I'm glad I did.

After replacing the seal, I polished the key, keyway, shaft, and the inside diameter of the flange. I then greased everything up and put it back together. Pulling the flange is now an annual maintenance event (not changing the seal).

Don't forget to burp the Volvo seal and add the grease.

[MalcolmP]

Apr 26, 2024 14:59:03 GMT salty said:

Or is the taper / key also preventing the shaft from moving astern from the flange? Do I need to pop the flange astern on the shaft to release the key before I'll be able to slide the shaft out? 

Hi Salty.

Yes a hydraulic puller is best, if you might borrow one. If you can get some heat, maybe with a hot air-gun onto the coupling it may help.

Look forward to hearing that you have it removed without damage.

Good luck Malcolm

[Charlie-Bravo]

Having got it under a lot of stress with a puller, diy type mechanical or hydraulic, and applied heat via blowtorch (don’t set the boat alight !) or hot air gun, wait , put the kettle on and make tea, drink tea, re heat and then apply a shock load with a biggish hammer and it should come apart possibly with quite a bang, if it doesn’t come apart you either haven’t hit it hard enough, or the puller isn’t applying enough stress.

hope it pops off for you

CB

[seattledale]

Hi Salty

Boy, I know the feelings you're having.  I replaced my seal last week.  I made a rather long post a few days ago of my experience.  You probably already saw it, maybe it's of some use (see "My replacement of the Volvo-Penta seal on a 43DS" 24Apr24).  The seal is the easy part; it's getting that coupler off the shaft is the challenge.  Hopefully your coupler/shaft interface is also a tapered type.  I had investigated doing what you're suggesting using the transmission flange squeezed against the coupler flange with a socket in between to force the shaft out.  But I saw too many cautions that this can distort the transmission flange and cause all sorts of damage inside the transmission which opens up a whole new world of hurt.  As you can see in my posting photos, I used a separate disk to do the squeezing with hardened Grade 8 bolts, washers and nuts.  And heat...lots of heat.  When it goes there's quite a bang; that's the nice thing about a tapered shaft.  With the caveat that all boats are different, let me know if I can be of any help.

Dale

[rene460]

Hi Salty, one to the forum.  That seal is certainly a baptism of fire in your ownership.

I can’t add anything to the ideas others have contributed above but you asked two question which have not been addressed.

First, the fit of the flange on the shaft end is a standard ISO taper.  Your search engine will give you the detailed dimensions.  So no, you physically can’t push the flange further onto the shaft, and it is not necessary.  The flange position is determined by the dimensions of the taper.  The key is to stop the flange turning under torque loading, but plays no part in holding the flange axially.

Also I would not recommend use of the engine/transmission flange as part of your puller system.  The engine shaft is fully located by bearing in the engine and gear.   There is a risk of the propellor shaft or the crankshaft being damaged if your flange tightening technique is not perfect as neither the propellor end of the shaft nor the engine shaft can move laterally to accomodate the flange faces not being parallel, while the normal puller arrangement does not transmit that potential bending to an critical components, the puller flange just sits where it wants to.  But you are not the first to find that a standard puller does not fit.  There is never an available spare inch in a boat.

I suspect the reason the flange is so hard to pop off the taper is a degree of corrosion seizing the flange to the shaft.  Some heat to the flange harnesses some differential thermal expansion which is your friend.  Try and shield the shaft to minimise heating of the shaft as far as possible.

All the best for a successful job.

Rene460

[salty]

Apr 26, 2024 20:53:50 GMT seattledale said:

Hi Salty

Boy, I know the feelings you're having.  I replaced my seal last week.  I made a rather long post a few days ago of my experience.  You probably already saw it, maybe it's of some use (see "My replacement of the Volvo-Penta seal on a 43DS" 24Apr24).  The seal is the easy part; it's getting that coupler off the shaft is the challenge.  Hopefully your coupler/shaft interface is also a tapered type.  I had investigated doing what you're suggesting using the transmission flange squeezed against the coupler flange with a socket in between to force the shaft out.  But I saw too many cautions that this can distort the transmission flange and cause all sorts of damage inside the transmission which opens up a whole new world of hurt.  As you can see in my posting photos, I used a separate disk to do the squeezing with hardened Grade 8 bolts, washers and nuts.  And heat...lots of heat.  When it goes there's quite a bang; that's the nice thing about a tapered shaft.  With the caveat that all boats are different, let me know if I can be of any help.

Dale

Thanks to everyone for the moral support and advice! Dale I had not seen your (excellent) post - I did this work earlier in the week then took a day off for the wife's bday and got around to posting this without checking for new content here. Your info helps a lot, thank you. 

I'm handy but learning as I go. I checked with my yard and they don't have a puller that'll fit the space. It looks like this one might fit and thought to ask this group's input before I order. Noting that I'm unlikely to find spare '70s BMW parts that perfectly fits, I thought I'd be paying nearly the same for a fabricated plate plus four hardened bolts/nuts anyway, so might as well try the puller. 

Malcolm I see that you replaced your coupling with a flexible option a few years ago. Did this require a new shaft or any modification to your existing shaft? As long as I'm in here I'm willing to spend a bit to upgrade this integral component. Are flexible couplings effectively bolt on or will I require further modification(s)? 

Thanks again everyone. 

[seattledale]

Salty

That looks like a nice puller and you can't really complain about the price.  Considering the charges for the round-trip haul, the lay days, your time, Cad$82 sounds like a gift.  I like that it's a 3-point puller, better than a 2-point which is part of the reason I didn't bother with the couple of 2-points I had been lent.  They give all the dimensions so you should be able to determine whether it will fit.  On my 43DS there is a remarkable amount of room once the prop is pulled aft to get the coupler free from the back of the transmission.  Hopefully yours is similar.  Lots of fast heat, like everyone else is saying.  I was told getting the coupler up to 200degF would do it; an infra-red temp gun or one of those temperature melting wax pencils will give you an idea of the coupler body's temperature.  Being an ISO taper, all the coupler has to do is to expand a tiny bit relative to the shaft, and it will literally explode off the taper.  I didn't have to tap mine; it came off by itself when it decided the time was right.  But some hammer tapping on the outer body of the coupling may hasten its decision.  Obviously don't hammer the machined flange surface.  As I posted, I had threaded the big nut back on to the threaded end of the shaft just a couple of threads.  That would stop the coupler from launching itself forward toward the transmission when it lets go, although I sort of doubt it would actually become a missile considering how heavy the coupler is. 

Good luck, and that big BANG will be the happiest sound you'll hear all day!

Dale

[MartyB]

Assuming we are talking the part on the front of the drive shaft that connects to the flange on the trans......
I too did the socket/bolt in between the two parts, Some long bolts. Once it started moving. I only needed two of the four bolts to pull the flange off the shaft. Once I had the parts, all of 15 min of time. Pretty simple frankly. I know in the past, mine as been off at least two to four times. It may be looser per say than your boat, if that flange has never come apart since leaving the factory.

Marty

[tarn]

Hi There’s quite a lot of info regarding this . I posted a couple of years ago check my past threads.
Cheers Tarn