Early Mercruiser Outdrive Bellows Repair

[dusted_ya]

I have a 1970 Starcraft with a 120hp Mercruiser I/O that I've restored. When I first started the restoration a few years ago I hired a guy to replace the bellows and gimble bearing. Now it's restored and have had the boat out about 6 times and have started to notice water in the bilge area. The other day I opened up the engine cover and noticed water pouring into the boat. Upon inspection afterwards I noticed a tear in the drive shaft bellows about 2 o'clock. My buddy said he must not have replace the bellows and it started to tear with age. Since the boat is 48 years old there is NO ONE anywhere that will take it in for repair so I'm it for all repairs.

I removed the outdrive and gimble housing to start replacement and the bearing is got a definate rattle when I spin it by hand so it will need to be replaced. Also it appears that all the bellows were in good shape as if they had been replaced recently. The driveshaft bellows has two opposing flat spots on one end and they were installed at the 3:00 and 9:00 positions (is this correct?) Not sure what caused the tear other than possibly the inner ears of the gimble housing where the pivot pins are.

Was this tear a fluke? Was something installed improperly? I can not find anything on the internet showing proper installation. Also I need a transom seal kit but don't know which one I need for the pre-alpha model. SN: 2728089

Thanks for the help!

 

[alldodge]

The flats do go at 3 and 9, and for it to tear fail that quick there was an issue. Boots could have been New Old Stock. Need to watch for NOS on ebay and such places. Would also suggest use only OEM boots

 

[GA_Boater]

When you say the bellows was replaced "a few years ago", how long was a few years? And when the boat is off the water, do you store it with the outdrive down or down? Stored up can help reduce the life of the bellows.

Nice looking Holiday, dusted.

 

[dusted_ya]

Thanks AllDodge. I kinda figured the flats were to keep the gimble ring ears from grabbing a boot rib during hard steering which is what appears to have happened based on this photo. I would like to try to avoid that again if possible. I still haven't found a transom seal kit for this boat.

 

[dusted_ya]

The bellows was replaced 3 years ago. Most of that time the outdrive was in the down position during restore. I have been keeping it up about half way recently to avoid damaging the skeg during transport. I am new to I/O boats so I didn't know they need to be stored all the way down. Good information! If you click on the link to the image I tried to post you can see the tear. Don't know why this forum won't let me post pics as it says "invalid file" every time...

 

[alldodge]

Can see needing boots but you need a transom seal? Its the one which you have to remove the motor an transom assembly to replace?

Being yours is a 1970 boat but the drive is probably a 69 I'm thinking the boot should be 36223A2 but need to verify with Bondo or BT Doctur

 

[GA_Boater]

Photobucket is holding our pics hostage.

I managed to get the pic to show for now and that is a tear. You may be right about the bellows catching on something.

The comment about storing the outdrive down is only for storage. On the road it won't hurt to raise it to avoid road rash on the skeg. Just drop it down when you get home so the bellows is straighter.

 

[dusted_ya]

Thanks GA! I found the kit I need here: http://www.ebay.com/itm/370872897014

I called the guy selling these kits and he said that the ridged drive shaft bellow is used for the early ones as well as it will help make a better seal. He also said that the reason why my tear occurred is because the bellow was installed incorrectly. The flat spot needs to be going towards the water hose and the shift cable so when you steer hard these don't push the bellow into the gimble ring ear.

 

[dusted_ya]

Well finally got the boat back together. What a huge PITA! Now I see why most people want outboards... I learned a ton during this process. Here's some points that might help others:

DISASSEMBLY:

1. Put your shift lever all the way in forward gear then remove your outdrive (six bolts and wiggle it out).
2. That little hole on the port side of the housing that is to access the inner hose clamp on the exhaust bellows sucks! Neither a long screwdriver nor a flexable driver would reach it for me. Hole needs to be bigger or farther from transom to be effective
3. Cut the old bellows in half (don't bother trying to save them)
4. On the early out drives you remove the gimble ring by removing a nail by each pivot pin (they come out towards the back of the boat). turn the drive to one side to access the pivot pin (has #12 threaded hole in center of it) then take a #12 bolt and thread it and pull it out. Repeat on other side. There will be a fiber washer on each side you need to remove and save for reinstallation. Also remove the grease zerts on each side (this will help during reinstallation of the drive shaft bellow).
5. Gimble bearing can be removed by removing the giant snap ring. You can make a slide hammer out of a 2 ft piece of 7/16" all thread. and a wing nut. The wing nut fits inside the bearing center at an angle then when straightened out and pulled on, center's itself. I used a chunk of steel with a hole in it for the hammer.


CLEAN CLEAN CLEAN ! ! !

Clean all mating surfaces of grease etc.

REASSEMBLY

1. My unit didn't have a greasable bearing housing so I could have purchased a more expensive sealed bearing or use the cheaper greasable kind. I used a bearing packer to pack it with marine bearing grease then after install pack any crevice behind it with more. When reinstalling the bearing get it started then gently tap along the outer perimeter in a circular motion it should be snug but not tight. Don't let it bind. I use a 6" long piece of aluminum dowel and a ball pein hammer.
2. Install the water hose into the transom. This needs to be 13 1/2 inches long. Use premium heater hose if possible and coat the inside with something like soapy water to help slide onto fitting (I prefer spit...)
3. Install the drive shaft bellow onto the transom using bellows adhesive on both pieces. Make sure the hose clamp is in the 3 o'clock position and facing down and the flat spots on the bellow are at 10:30 and 4:30 to allow free movement of the water hose near the transom.
4. Install the exhaust bellow. No adhesive is necessary but soapy water will help here as well. I've been told the clamp needs to be at 12:00 and facing to port but I found installed at 9:00 and facing up is super easy to get to with a box end wrench.
5. Install the water hose to the gimble ring (or whatever it's called). Your clamp should be at 9:00 and facing down
6. Install the drive shaft bellow to the ring / bell thingy. I recommend doing a dry run here to see what to expect. Use a fair amount of bellows adhesive. Your clamp should be at 9:00 and facing down (all the clamps on the ring are at 9:00 and facing down) and just barely snug enough so it doesn't move during install. First thing after gluing is to line up the ring onto the bellow and shove the ring as far forward as you can to seat the bellow. While pushing in on the ring You will be reaching inside the bellow cavity and feeling for any flat spots exposed. (you should only feel ribs). grab a couple ribs back and pull the bellow as far onto the ring as possible working your way around. Once you feel like the bellow is all the way on keep pushing on the bell for 5 minutes minimum. After 5 minutes relax and take another 10 minute break to let the bellows adhesive harden. Now you can reach up from below with a long neck screw driver past the water hose clamp and tighten down the bellow clamp. Be sure not to push on the clamp until it's snug as you don't want it spinning (that would be bad).
7. Install the exhaust bellow onto the ring. Again your clamp will be at 9:00 and facing down like the rest. No adhesive necessary. I would try to stretch it out some before this (not sure this helps but I did it anyways). Soapy water again to help it slide onto the bell. Start by shoving the bell as far forward as possible to get the bellow started. Next use something to reach inside and pull the bellow in place. Here I used a cats paw (a small carpenters tool for removing nails) and used electrical tape to cover the sharp points on the end. lay down and look up from underneath to ensure the bellow is properly seated then tighten down the clamp

BAM! DONE! Well sort of...

8. Now put your fiber washers and pivot pins back in the ring,
9. When reinstalling the outdrive use bellows adhesive to secure the big rubber seal that goes around the drive shaft housing (near the inner U-joint) and the water seal o-ring on the ring. Use RTV silicone to secure the gasket to the ring as well.


That's all I can remember for now...