DP-SM Bellow help

mandmj

Seaman
Joined
Jul 11, 2006
Messages
60
I need some help w/ a u joint bellows issue on my DP-SM, p/n 386-8913 w/ transom asbly SX-MBAC. Last year I did a bellow service (using OEM volvo bellows) to replace the original (2005) bellows. The rubber was deteriorated externally, but intact, and no water intrusion, etc. I followed the factory svc manual with the exception of 1 step. I couldn't locate any Volvo Penta Gasket Sealing Compound that was called for (discontinued according to several sources). I had found on the forum at some point that some used permatex to replace this, and some put the bellows on dry. I used the permatex after thoroughly cleaning the mating surface of the transom assembly, and confirmed several times that the ridge on the bellows was in the groove on the transom assembly. I had also seen a service bulletin posted by the late Don about over tightening the bellows clamp, and I have no torque spec for the clamp, but I could see the bellow distorting w/ only light tightening torque, so I stopped tightening at that point (much lighter than I would have preferred for a radiator hose clamp, etc). I also replaced all the o rings/etc while I had the drive off, as well as alignment. Fast forward a year, and I pulled the drive last night, and the bellows are full of rusty water. I can see no evidence of water intrusion from the rear of the bellows (nose of the drive), so I'm assuming at this point it came from the clamp side of things (it was late and started raining so further investigation is pending).

At this point I will replace the gimbal bearing, new oem bellows (again) and the ujoints (they feel fine, but better safe than sorry) and drive oil (hopefully not full of water). I am trying to figure out what went wrong w/ the bellows install. Should I use the dreaded bellows adhesive? silicone? nothing? Any thoughts or ideas would be helpful. I am reasonably mechanically adept and am disappointed this has happened and want to ensure it doesn't occur again.

Thanks.
 

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
30,454
Another source for water intrusion in there is the grease tube that feeds the gimbal bearing from the external zerk fitting.

I install my bellows dry and never had a leak.
 

mandmj

Seaman
Joined
Jul 11, 2006
Messages
60
Thanks Bruce. Can you give me an idea of how tight you make the clamp? Say, w/ a screwdriver or nutdriver, firm, as tight as you can, etc? just looking for some ideas...
 

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
30,454
I believe the instructions come with the torque value. Its is a very low number so you have to have a 1/4" drive torque wrench.

Also, make sure you have the clamp in the correct orientation. If it's too low, it will hit the bellows in a turn and cause a hole in the bellows. Did you inspect your bellows after you found all the water?
 
Last edited:

mandmj

Seaman
Joined
Jul 11, 2006
Messages
60
I've ordered new bellows, so i'll check the torque values, but I don't remember seeing them on last years work. I did find a sticky here I think it was listed as about 40-66 inch/lbs.

http://forums.iboats.com/forum/engi...114-replacing-bellows-on-a-sx-drive-pic-heavy

I have a 1/4" drive torque wrench so that wont be a problem. The clamp orientation was per the manual.

I was able to work on it some more tonight and after removing the pivot housing, decided to pull on the bellows to see what would happen, and they came off very easily. My 9 year old son could have pulled them off w/o trying. So i'm betting that is the problem, installer error. I could find no other holes, etc in the bellows. I also pulled the gimbal and no signs of water in the grease tube so i'll leave that alone for now.

I'll get all the parts in and button it up in a week or 2 hopefully.
Thanks for the help.
 
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