OMC Gimbal Bearing and Bellows Install

[drexton311]

I have been all over the internets and have not found exactly what I am looking for. I hope you can help. There seems to be a lot of info on the Alpha drives but not the Cobra drives.

I have a 1988 OMC Cobra with Chevy 5.0 and 2bbl carb. Model# 502APRGDP
I purchased the Sierra 18-2771 which contains:
18-2613 Outdrive Gasket Set
18-2765 U-Joint Bellows, replaces O.E.# 983973, 987467
18-2764 Exhaust Bellows, replaces O.E.# 914036
18-2763 Shift Cable Bellows, replaces O.E.# 911826
18-2100 Gimball Bearing, replaces O.E.# 983937
18-7315 Hose Clamp

1. What is the P/N for the grease/oil seal that installs before the gimbal bearing? - I cannot find this P/N anywhere and the iBoats schematics have the part pictured but not identified as a seal. Anyone have any idea?
2. Can I replace the bellows without removing the pivoting portion of the Transom/Stern assembly? I do not want to mess with adjusting the cable that I would have to disconnect if I remove it as instructed buy the OEM Manual. If I can, what are the chances of damaging the cable? I am worried about not setting the cable correctly as I have heard horror stories and currently the boat shifts flawlessly.
3. I'm deciding if I want to replace the u-joints at this time as I am not sure how old they are. (same reason I want to replace the gimbal bearing) I have no experience with u-joints, what is the best way to replace them and is there a "cheaper" alternative to using the marine joints. can I use auto, does anyone have a P/N?

Thanks all!

 

[bruceb58]

I highly suggest installing the OEM U-Joint bellows instead of Sierra.

Don't bother replacing the seal in front of the gimbal bearing.

Hard to imagine being able to change the u-joint bellows without removing the pivot housing. Buy the 2 adjusting tools and you won't have a problem with the cable.

 

[drexton311]

Bruce - Is there a quality issue with the Sierra bellows? Can you help me out with that adjusting tools you are referring to?

 

[Lou C]

I agree with Bruce on two points:
1) the quality of the OE bellows is superior, I have had them last 10 years and longer.
2) while some people say you can change the bellows on a Cobra or Volvo SX (similar transom design) with the pivot housing in place by removing the exhaust bellows first, there is really not much room in there, to see and feel if you got the bellows properly seated on the gimble housing flange. There is a groove in the flange, that a rib in the inner surface of the bellows mating surface has to fit into for it to be seated. The only way I'd try the short cut is if the bellows definitely had to be changed and the hinge pins were seized in place.
3) They way you can do this without altering the shift cable adjustment: do not disconnect it at the pivot housing end. Instead go up on the engine side and disconnect the cable at the engine bell crank shift lever. Then there is a trunnion that fits into the load lever retained by a cotter pin. On some cables this is adjustable and is part of the adjustment. I just taped this in place with duct tape so the adjustment would not change. This enabled the shift cable to slide down the bigger tube so that I could pull the shift cable out enough to properly change the bellows. Then when done, you just slide the trunnion back into the load lever and re-connect the end of the cable at the shifter bell crank.
4) Be careful with the hinge pins, you do not want to strip them. There are also fiber shims that go between the pivot housing and the transom mount, these will probably be worn and should be replaced. Getting them in proper position so that they line up with the holes can be a bit of a struggle, I put some triple guard grease on them to make it easier. I also put OMC gasket sealer on the thread of the hinge pins to seal out salt water and corrosion.
5) To remove the exhaust bellows, you need a snap ring tool because a large snap ring retains it on the pivot housing end. Wear eye protection when you do this because if you slip it can fly off.

As far as the adjusting tools, I got the OE OMC tools from Crowley Marine a few years back. There are also a number of aftermarket versions of the same tools, except the one you use to measure the height of the shift rod. This can be done with a ruler if you re careful.

http://www.crowleymarine.com/johnson-evinrude/parts/55473.cfm?mdl=B9XORH

 

[drexton311]

Lou - Thank you for the information! I went ahead and ordered new washers per your input and U-joints from iBoats and I also called Crowley marine and they were unable to help with a shifter adjustment tool without a P/N (I also could not find one on their website). By chance, do you remember the P/N of your tool? Google searches are not much help as I am not sure exactly which tool I need, there appears to be a few different types. I think I might have to remove the linkage if the cable boot is bad, so I want to be prepared in case I am forced to. As I just bought this boat this year, I have no idea what shape these boots/bellows are in.

 

[bruceb58]

http://www.ebay.com/sch/i.html?_odk...+tool.TRS0&_nkw=omc+cobra+shift+tool&_sacat=0

 

[drexton311]

Thanks Bruce!