Help with Outdrive Removal for Bellow Replacement...

[ConnieMarie]

So it was an absolute bear to remove my outdrive the past couple days. I tried all the tricks and could not get it to pop, I thought for sure the spines were rusted to the drive. Today the only way I could get it off was by removing the triple square type pivot pins on the bell housing and it came off no problem. This all started because the end of plast season I saw my drive bellows were cracking and wanted to replace before this season. The drive itself did not show mush rust issues maybe very slight around u-joints but nothing concerning I plan on greasing the hell out of everything before reinstall. So the back half of the outdrive by the six bolts is more or less corroded together, when I say I tried everything I was whacking the hell out of it, air hammer to studs, generous lube. I did not try heat. Anyways my question is, will I be able to put the new bellows on without getting the back half of the drive apart? As far as I know inside are just the metal fastener rings, which I think I can get in and at the transom end of the bellows are hose clamps which I was able to remove with a screwdriver on the removal. Obviously the water hose will be an absolute b*tch to get back on but with time seems like it can be done. Then its just a matter of getting pivot pins back in and assemble the rest. Sorry about the lengthy post. I should mention its a Volvo Penta SX drive.

 

[ConnieMarie]

I probably left some information out. I did try using 2x4, metal wedge, dropping the outdrive onto 2x4 a couple times, trim rods, big hammer, screwdriver, chisel. This thing will not come apart. Dont want to break it because its cast aluminum and I really dont want to buy a new one.

 

[ConnieMarie]

While I have it apart I wonder if I should replace the u-joints as well. They don't seem too bad as far as play goes...any thoughts?

 

[Lou C]

With the SX drive there is no way you can replace the bellows without separating the outdrive from the pivot housing. The way the bellows seals on the outdrive end is that the bearing carrier pushes into the part of the bellows that basically pops into the pivot housing. The other end is held on by a clamp on the gimble bearing flange. If you have the pivot housing off still bolted to the drive, I'd try to use heat CAREFULLY to get it to break free. You have corrosion on the mounting stud area that has fused the 2 aluminum castings together. Volvo did not use a gasket between the drive and the pivot housing there like OMC did (Volvo adapted the OMC Cobra transom mount design with some differences). Heat, and plastic or wood wedges, carefully used may work. If not, I'd consider taking the whole mess to a machinist and pay them to do it.

When you do get it apart, I'd consider replacing the u joints if they are the replaceable style, if not you have to replace the driveshaft (another bad Volvo design change from the OMC original). Check the gimble bearing carefully, if any doubt about it replace that too. When you reinstall the drive:

coat the driveshaft splines in OMC/Evinrude triple guard grease
oil the 2 orings on the drive shaft
coat the mating surfaces of the pivot housing and upper drive unit where the 6 studs are with the same OMC/Evinrude grease to prevent a recurrence of that corrosion
I also use OMC gasket sealer, or Permatex Perfect seal on the threads of the 6 mounting studs.

The fact that OMC used a gasket there, that you coated on both sides with the OMC gasket sealer, pretty much prevented corrosion there and the drive would come right off as long as the u joint bellows had not leaked rusting the gimble bearing on to the drive shaft.

 

[ConnieMarie]

Lou I appreciate the lengthy reply and advise. Just to clarify my upper outdrive is stuck to the pivot housing. I removed the plastic cover...can I pull the bearing carrier out that way? Also, if it comes down to heating all I have is a hand torch not oxy/ace would that suffice?

 

[ConnieMarie]

Just took a quick glance at it before work...seems infused together. Any thoughts on running a dremel disk but up and down each crack on each side? Would this ruin the deal by making the gap too big? From what I gather it really isn’t a water tight seal to begin with

 

[Thalasso]

Should have put 2x4 on the top of drive between it and the gimble ring. Trim the drive up should have separated it

 

[ConnieMarie]

I tried the 2x4 numerous times.

 

[Lou C]

I don't think you can do what you are considering, and even if it were possible, what is the point? Even if you could, are you prepared to re-set the backlash of the upper gears?

You need to get the drive and the pivot housing apart without destroying anything. Those parts are very $$$ to replace, even if you find them used. I would try some heat even just a propane torch near the 3 mounting studs on each side, and a plastic or wood wedge. If you can't get it that way, then haul it off to a machine shop and pay the man. You will be far better off. Then follow my instructions above for the yearly R+R and never have that problem again.

 

[BRICH1260]

Maybe try pouring some CLR between the halves and let it soak down to the corrosion that is holding the halves together. It worked for me separating the upper and lower unit of my drive last year.

 

[Lou C]

worth a try! Anything is better than scarring up the mating surfaces even though it does not have to seal anything there.

 

[ConnieMarie]

Still stuck...tried heat on the lugs went up and down the seem quite a bit with a dremel disk bit. It looks like the two pieces are practically welded together. Just out of curiosity is there a flange on one of the pieces maybe it makes no sense running the blade in between them. I can see through toward the very bottom to the other side(daylight). I’ve used a screw driver a few times and still won’t come apart. I’ve been soaking in penetrating oil for about four days now. I guess I’ll give the CLR a shot tonight

 

[ConnieMarie]

Have it soaking with CLR overnight. For what it’s worth the drive is a SX-M 1.51. Don’t see there being anything specific to this model. I may have to buy a whole new drive this thing will not come apart. Can I put a 1.97 on? I want to stick to single prop just wondering the difference with gears.

 

[dypcdiver]

Direct heat on the exposed ends of the studs, then hammer around the same area.
It will just be the corrosion around the studs that is holding them together.

 

[ConnieMarie]

I’ve tries heating studs about a dozen or so times. maybe it’s because I’m using a handheld propane torch and it’s not giving off enough heat? I’m also concerned about damaging the ends of the studs at this point too. Perhaps if I put the nuts back and this will help. I sprayed CLR in and around studs last night so hopefully that helped

 

[BRICH1260]

One of my drives was so bad that when I finally got it separated, it brought out the gimbal bearing with it. Because of bellows water intrusion it has seized to the drive shaft. I was able to finally separate it by blocking the drive and using the trim rams. I know you have tried this, but I would stick with that method rather than trying to pry the two halves apart, you will only end up breaking the casting I`m afraid.

After the CLR has soaked in well, go back and try using the trim rams again, there`s a lot of force there.

 

[Lou C]

How about carefully heating one piece (pivot since there are no seals in it), then putting ice packs on both sides of the other piece (upper gear housing) ie getting one side to expand while the other contracts? Maybe a 2 person job, both wearing heavy gloves lol!

 

[Lou C]

Have it soaking with CLR overnight. For what it’s worth the drive is a SX-M 1.51. Don’t see there being anything specific to this model. I may have to buy a whole new drive this thing will not come apart. Can I put a 1.97 on? I want to stick to single prop just wondering the difference with gears.

If the 1.51 is right for your engine/boat, do not change to a 1.97. What this means is that with the 1.51, your engine makes about 1 and a half turns for every turn of the prop. With the 1.97, it will make almost 2 turns for every turn of the prop and you will get faster acceleration but considerably lower top speed. Also, you would have to change the prop (going to a higher pitch) to keep the engine from over-revving at wide open throttle. If the boat has performed well with the 1.51 then that's what's right for it.

 

[ConnieMarie]

All very informative thanks guys. I’ll try throwing it back in and use the rams. This thing is a major pita. As mentioned before I have been carefully using a dremel which I’m sure has compromised the two mating surfaces but it still hasn’t budged. Actually from what I can see where each lug goes through it looks like pure aluminum. I’m not sure if P.O. has this thing welded together or what nothing seems to be working very frustrating. All for a bellows replacement. I hope I don’t break the transom on the boat.

 

[Lou C]

This is why some people in salt water regions hate I/Os with a passion, if they are not carefully maintained, these problems can be common. In the salt pond we remove drives every year usually, so that we don't have to go through this....