Bellows Q's

[johnnynegaunee]

You folks have provided me with answer you can't find in the manual, for that I say thanks. Well I got a few more.... I'm realitively new to I/O's. I have a '72 3.0L Merc.

When I first put the boat in the water I started her several times with the drive up and the R's at 1-2K before saying oops and lowering the drive. That said, recently I find the outdrive u-joint bellows leaks greatly when its up and in the water, but no leaks with the drive down. I'm now trying to replace it. I see scoring on the inside of the rubber. Is this from running the drive in the raised position? Or is there another problem to correct? In the manual it looks like I need to disconnect the shift cable at both cable ends, is this correct? And why?

 

[achris]

Re: Bellows Q's

Which manual are you using, Merc genuine or one of the rubbish after-market ones? I have done quite a few bellows replacements and never have to disconnect the shift cable....

Chris........

 

[Bondo]

Re: Bellows Q's

Ayuh,....

If you're going Deep enough to replace the Bellows,...
You otta be replacing the lower shift cable,+ All the rubber parts in there....

Do you have the Factory Manual,....
It's a Huge,.. HUGE file..... Give it Alot of time to download...

 

[johnnynegaunee]

Re: Bellows Q's

In fact I was fortunate enough to get a '74 merc. manual with a donor boat I used to replace the engine last spring. Unless I'm reading in the wrong section of this manual, it has as one of the steps removing both ends of the shift cable, in order to remove the bell portion of the gimbal assembly. I was hoping to get by with just taking apart the outboard end. Is this possible?

The pins on which the bell pivots look like they could be moved inward some to tighten up these joints, is this possible? Or do they need replacement?

And I'm still wondering if having run the u-joints with the drive up is the cause of the scoring I see on the boot? Or should I look for another problem as the cause?

If I regrease the gimbal bearing what's the best grease? Synthetic?

Thanks,
John

 

[APPALOOSA2]

Re: Bellows Q's

The bellows is just old at that age and crack in the ridges. Do you put the boat in gear with the lower unit all the way up ? Do you have a trim quage.
You should only have the lower unit about half way up when in gear. Its pretty tough on the ujoints and Gimbal bearing to run in all the way up in gear.
While your at it grease that gimbal bearing, on the older units like yours their is no grease fitting. Pack gease by hand behind it.

 

[Uraijit]

Re: Bellows Q's

NEVER run your drive in the up position!

 

[Maclin]

Re: Bellows Q's

The bellows is just old at that age and crack in the ridges. Do you put the boat in gear with the lower unit all the way up ? Do you have a trim quage.
You should only have the lower unit about half way up when in gear. Its pretty tough on the ujoints and Gimbal bearing to run in all the way up in gear.
While your at it grease that gimbal bearing, on the older units like yours their is no grease fitting. Pack gease by hand behind it.

Good advice here, but I must add that the u-joints are spinning anytime the engine is running so the caution should not include anything about "drive in gear", instead it should be worded "while engine is running"

 

[45Auto]

Re: Bellows Q's

Shouldn't be any scoring from the u-joints on the inside of the bellows.

I use Quicksilver "U-joint and gimbal" grease on the u-joints and gimbal bearing. But I also use Quicksilver "Spline" grease on the drive shaft splines and prop splines. Means you'll have at least 3 grease guns by the time you get to the wheel bearing grease (I think I have 5). Depends on how critical you think having a certain type of grease is. As Bond-O says, "Any grease is better than no grease!!".

You only have to disconnect the shift cable on the outdrive end if all you're doing is replacing the u-joint bellows. But while it's that far apart you ought to replace the shift cable bellows also. Replacing the shift cable bellows requires disconnecting the cable from both ends and removing it from the boat because the end inside the boat is what has to pass through the new shift cable bellows. If you plan to replace any trim senders do it now while you have the bellhousing off.

Not sure what you're talking about "moving the pivot pins in to tighten up the bellhousing". The bellhousing should be a tight fit inside the gimbal ring with some plastic or fiber "rub" discs between them. The pivot pins just screw into the bellhousing until they bottom out, the bellhousing pivots on the outside of the pins. Only way to tighten the bellhousing up would be to bend the gimbal ring.

 

[Don S]

Re: Bellows Q's

The pivot pins just screw into the bellhousing until they bottom out,

Close, but he has a One drive, and they don't have screw in pivot pins. They slip fit (Brass drift and hammer with corrsion fit). But they should have those fiber discs between the gimbal ring and pivot housing.
Also make sure the surface the bellows is attaced to on the gimbal housing isn't damaged. Sometimes the ujoints can hit the gimbal housing when tilted up, and it destroys the seal surface.

 

[JustJason]

Re: Bellows Q's

hehehe.... corrosion fit. love it!

 

[Fishermark]

Re: Bellows Q's

Unless I'm reading in the wrong section of this manual, it has as one of the steps removing both ends of the shift cable, in order to remove the bell portion of the gimbal assembly. I was hoping to get by with just taking apart the outboard end. Is this possible?

What are you calling the outboard end? If you are referring to the end that is attached to the helmet or bell housing, then you cannot unscrew that without removing the end inside the boat as well. If you do not intend on replacing the entire shift cable, then you do not have to unscrew the end in the bell housing. You will at least have to disconnect inside the boat in order to replace the shift bellows - which would be a wise thing to do at the very least.

The pins on which the bell pivots look like they could be moved inward some to tighten up these joints, is this possible? Or do they need replacement?

I recently did this on my dad's old boat, and took a few pictures as this was my first dealing with the old style pins. You will note from the pictures below that the pins / shafts are held in place with an aluminum nail - the head of which can be seen on the aft side of the gimbal ring. You simply look behind the nail head and straighten out the nail head and pull it out. Then you can either pull or push out the pin / cylinder. I don't remember the thread needed - it was either 1/4"x20 or maybe 1/4" x28? whatever it is you can thread the 1/4' bolt into the end of the pin and use a pair of pliers to pull out the pins... Or as Don mentions, simply punch them in to the middle.

There is a small hole at the top of the pins to simply help line them up upon re-installation, as you will need to be able to line the hole back up for the nail heads. Here's some pictures that may help:

 

[johnnynegaunee]

Re: Bellows Q's

Wow! Thanks Fishermark, I did have those nails out just as you describe, but only after a long while scratching my head. The tips of those nail are bent into a recess and not easy to see or straighten. My pivot pins are loose in the housing and can be pulled with a 1/4-28 bolt and 2 fingers(worn).

The shift cable end has a crimped sleeve on it, under the set screw. Unless I carefully cut it off without cutting the cable end, it looks like I will have to remove the entire cable from the cable housing/slide. Are these crimp on ends replaceable or does this lead to further problems? You said you replaced the boots on your Dads boat, how did you get just the bell housing end of the cable off?

Thanks

 

[Fishermark]

Re: Bellows Q's

I didn't just replace the boots - I replaced the entire shift cable as well.

I'm not sure what crimp ends you are talking about.... On the shift cables I am familiar with, there is a set screw that you will loosen to pull the cable out of the big plastic tube on the end. Then you unscrew the smaller metal tube on the end. There is a lock nut behind that if memory serves me correctly. There is a crimped end on the very end of the outer sheath... but that never comes off. It will stay on the outer sheath - that whole sheath is slipped through the rubber shift bellows. (And it can be a tight fit).

 

[johnnynegaunee]

Re: Bellows Q's

On this drive ('72, pre-alpha "R"? drive), at the bellows end of the cable I have a crimped-on sleeve pinched to the cable end. I am reluctant to pull the entire cable out of the housing for fear of not getting it back in. I'd rather not even pull it out of its regular travel (about 4") if I can help it. Have you removed and re-installed this cable into its housing? Is that how you got the bell completely free of the gimbal ring?

 

[APPALOOSA2]

Re: Bellows Q's

If you pull the cable out you will have to loosen the set screws at the other end inside the boat. I don't know how old your cable is but if it's over 6 years I would just replace the whole thing while everything is off, much easier.

If you change it all you should have no worries for quite a while.

 

[Fishermark]

Re: Bellows Q's

Is this "sleeve" the shift cable bellows? If that is what you are talking about - then it ought to be replaced anyway. The good news is that it is fairly easy to do. If you are not talking about that.... then I'm at a loss.

 

[hoot]

Re: Bellows Q's

j; you or a shop will end up replacing the gimbal bearing and u joints too if you have water in the bellows. they may not 'feel' bad now, but they will degrade over time. on my boat, a 78 250 IL6 merc, the shift cable brass nut on the bell housing would not come loose, so i left it attached and loosened the cable inside the boat. if doing the work yourself, take pictures and make sketches and measurements of the cable fittings so you can get them close when reattaching them. watch for the little screws that you will drop. i think a new cable requires tapping the existing hole and attaching it opposite the boat side. this forum has a lot of good info plus there are websites with instructions. good luck.

 

[JustJason]

Re: Bellows Q's

that crimp on sleeve is just the clamp for the shift cable bellow.
If you don't know the last time the cable has been replaced, then follow bond-o's advice and replace it.

If your shift cable is threaded in the foward section of the bell housing your going to need to get a special tap to convert it to the newer style which threads into the rear section of the bell housing. Save the headache and just get the tap from Merc or take the housing to a shop and see if they'll tap it for you for a small cost.

What I do when I'm replacing the cables is I just cut the cable in the transom area, then I tape on some cheap primary wire to it, then i tape on the new cable to the primary wire and jump in the boat and pull it through. Make sure you pull the cable through the bell housing first. Your also going to need a special socket to install the new cable. You can get that from Merc. And pay attention to the routing of the cable.

That crimp will also come with a new boot kit. Toss it in the trash and ask the parts man for a fuel line zip tie. It's much easier to do it that way.

 

[achris]

Re: Bellows Q's

On this drive ('72, pre-alpha "R"? drive),....

Your drive is an 'MC-1'...

In order to remove the shift cable from its bellows you must first disassembly the inboard end of the cable. Once you have done that just pull the inner completely out. That's the wire with the crimp on the end... don't worry, it slides back in real easy....

If the cable is the old style with the outer screwing into the bellhousing from front... (where you can't see it by standing at the back and looking at the shift cavity in the bellhousing) then it would make very good sense to replace the cable at this point too. Once you have the old outer removed you're going to have to run a tap down the hole to clean the threads for the new cable... It screws into the bellhousing from the back.... much easier, but the threads are usually so bad they need cleaning up or you won't get the new cable in.

Then it's just reverse the disassembly and it's back together.... but then you'll have to adjust the new cable.... Ask for help when you get there...

Chris................

 

[johnnynegaunee]

Re: Bellows Q's

Thanks everyone for the input, you all are very helpful and now I understand how it's assembled. Should go OK, I think attaching a wire to the cable sounds like a good idea, I'll do that.

One last question, the G-bearing I think I'll change while I'm in there, can I use the newer greaseable Alpha style or will I need to use the older sealed version?