Need to change U joints on volvo/penta cobra SX outdrive??

[familyguy]

Does this sound like I need to replace the U-joints? I have an SX-M 1.79:1 gear ratio oudrive on my engine. I have had the boat almost 2 years (2nd owner) and for the last 9 months I have noticed a high-pitched whine-almost-grinding sound (it wasn't present the last year and 3 months) come from the rear of the boat only when at WOT and only when trying to make slight adjustments in trim to find the planing sweet spot at this WOT speed. It doesn't happen any other time, i.e. at lower RPMS. A boat mechanic friend said it's the U-joints.

So I figure it's time to pull the vertical outdrive off the pivot housing since this is reccommended annual maintenance anyway and I don't know if it has even ever been done to lubricate the U-joints and drive shaft splines. I'm trying to get all my ducks in a row and have all parts, tools, seals, and gasket sealer in hand before I start so I can knock it out in a day, two at the most with my dad. If it sounds like classic U-joint breakdown I'll just go ahead and shell out the dough for the expensive heavy duty puller ($179) and the U-joints ($42/each) so it's all in hand.

Advice? Any recommedations regarding where to purchase these items? I've done some online searching since the local VP service center is repeatedly dodging my calls about obtaining needed items so I can do it myself.

 

[Sparkinator]

Re: Need to change U joints on volvo/penta cobra SX outdrive??

Sounds like a plan.

I'd change the u-joint bellows and exhaust bellows while you're at it. Really easy job while the drive is off anyway.

I just changed both my bellows, checked alignment and gimbel bearing and it was really easy. Just remember to disconnect the shift linkage before you start to remove the drive. Also, be prepared, the drive is pretty heavy and cumbersome when you get it removed.

 

[familyguy]

Re: Need to change U joints on volvo/penta cobra SX outdrive??

Copy that, but does the sound I described and timing of occurrence indicate classic U joint breakdown?

 

[Gary H NC]

Re: Need to change U joints on volvo/penta cobra SX outdrive??

possibly,or the gimbal bearing.
Remove the plastic cover from the upper part of the drive and unhook the shift cable.

There is a SX manual in the Adults only thread...read up.
I actually enjoy working on the SX.Not really difficult once the drive is off and hinge pins removed.

 

[familyguy]

Re: Need to change U joints on volvo/penta cobra SX outdrive??

Copy, thanks for manual recommendation, already have a full set of engine/outdrive workshop manuals though. Now, between work and family, I just need to order the items and do it. I'm trying to figure out if I should go ahead and order the U joints and puller along with the other stuff or wait till I pull the drive.

 

[Gary H NC]

Re: Need to change U joints on volvo/penta cobra SX outdrive??

I would pull it and see.
I just did a 96 model.You will need a large set of snap ring pliers for the exhaust bellow.
They need to be the type that squeeze the snap ring smaller.
Autozone actually had a set of them with interchangeable tips for about 20 bucks.They had both the one that expands and the one that squeezes.

 

[familyguy]

Re: Need to change U joints on volvo/penta cobra SX outdrive??

Right, well, regardless I'm gonna pull the drive. Is there an easy way to tell if the U joints need replacing or just lubrication? I figure checking the gimbal bearing is easy once I have the drive off, but I've never replaced a U joint. Do I just check for excessive play?

I belive I have that very set of pliers with interchangeable tips from Kragen.

So, it sounds like I should definitely change the bellows too, huh? I was planning on just reseating the U joint bellows lip on the inside of the pivot housing with sealing compound as described in the manual as long as the bellows passes inspection (it looks okay from the outside). If I understand correctly, it's not that big a deal if the exhaust bellows leaks.

 

[Sparkinator]

Re: Need to change U joints on volvo/penta cobra SX outdrive??

If the exhaust bellows fails, it's not a big deal at all. If the U-joint bellows fails, it could easily cause the u-joints and gimbal bearing to fail.

I didn't use any adhesive on my bellows. The VP instructions didn't call for any.

 

[familyguy]

Re: Need to change U joints on volvo/penta cobra SX outdrive??

I didn't use any adhesive on my bellows. The VP instructions didn't call for any.

The VP outdrive workshop manual for my SX lists under Section 2, Transom Bracket Assembly, Pivot Housing Installation

"Step 6: Apply Volvo Penta Gasket Sealing Compound around the complete inner V-shaped lip of the pivot housing , to seal the U-joint bellows against water entry."

...then later
"Step 9: Insert the retaining ring inside the bellows" (the one Gary H NC refered to when using the snap ring pliers) to fully seat the bellows where it attaches to the pivot housing

 

[Sparkinator]

Re: Need to change U joints on volvo/penta cobra SX outdrive??

I don't think they recommend using adhesive any longer. You could PM Don to be ABSOLUTELY certain. I don't have the updates that VP sent out telling to not use adhesive, but here is a link where it is discussed.

LINK

The instructions I got with the VP bellows never stated to use adhesive.

 

[familyguy]

Re: Need to change U joints on volvo/penta cobra SX outdrive??

Sparkinator, thank you so much for the prompt replies and the link/update on the discontinuation of adhesive application during bellows installation. That's why this website is so great - many people to learn repair information from!

Once my dad and I get to this repair job I'll make sure to post anything useful we learned while doing it.

 

[Don S]

Re: Need to change U joints on volvo/penta cobra SX outdrive??

Here is the instructions that comes with the bellows. The instruction BOOK is 22 pages long and includes the XDP drive and all in about 10 different languages which is why I just post the one page.

 

[Sparkinator]

Re: Need to change U joints on volvo/penta cobra SX outdrive??

Familyguy
The instructions Don posted are the same ones that I received. They are pretty straight forward, but I didn't remove the pivot housing. Both bellows installed easily enough without removing it.

Good luck on your repairs!

 

[familyguy]

Re: Need to change U joints on volvo/penta cobra SX outdrive??

Thank you again gentlemen, and thank you Don, your sharing of knowledge has helped many...it's much appreciated.

My first line of business is to build an outdrive carrier, then pull the drive. I will inspect things next to see exactly what I need to replace, i.e. u-joints, gimbal bearing, bellows, before shelling out dough for parts I may not need (done that too many times).

I know I definitely need an alignment tool; this tool is what the local VP dealer was dodging my calls about. It looks like the cheapest I found was through eBasicPower ($70). I'm waiting to purchase that cause I'm hoping to get everything from one, maybe two sites.

Do I really need to pull the pivot housing to install the bellows if their replacement is needed?

 

[familyguy]

Re: Need to change U joints on volvo/penta cobra SX outdrive??

Sparkinator, I guess you answered that question. Wasn't sure if anyone else had any input on that though. From its outward appearance it looks like if I tilt up the pivot housing and pull the exhaust bellows first, I should have enough room to get my hands in there to remove the u joint bellows next.

Additionally, I didn't see anything in the bellows instructions Don included that states to use the adhesive when seating the bellows lip in the pivot housing. Can anyone think of a reason why NOT to use it? I figure if I have a choice I will go ahead and use it to provide extra water intrusion protection. If I want to peek in the bellows later when everything is installed I figure I can pull back the forward-clamped part of the bellows and inspect. Though I don't even think I would do this since I would be paranoid about unseating a properly secured water tight fitting. I would just wait till I pulled the drive again for regreasing.

 

[Sparkinator]

Re: Need to change U joints on volvo/penta cobra SX outdrive??

That outdrive stand will be helpful for pulling the drive. I will have built one by next year when I pull my drive again.

As far as adhesive on u-joint bellows. I bought this boat at the end of the boating season last year. Even though everything looked really good from a general inspection, I didn't know how well everything had been maintained. From that stand point, during the off season, I pulled the drive and inspected/PM'd all the required yearly maintenance. The only part that NEEDED replacing was the exhaust bellows, but not knowing how old the u-joint bellows was and not wanting to chance encuring some MAJOR repair headaches due to a U=joint bellows failure, I decided to replace it. It is CHEAP INSURANCE.

The U-joint bellows I replaced looked fairly new, but wasn't a Volvo Penta bellows and for that VITAL piece of equipment, I wanted the highest quality part out there. (I did keep the old bellows to use as a spare. It would do, if needed until I could get one ordered.) When pulling the old bellows off, I found NO water intrusion whatsoever and NO ADHESIVE used on either end of the bellows.

I also replaced my raw water pump impeller to avoid the problems associated with one failing while running the boat. The bellows and impeller are definitely replacement parts that should never be run to failure. An ounce of prevention (periodic replacement) is worth a pound of cure (sunk boat/ overheated engine/failed gimbel/failed coupler). You get the idea.

 

[familyguy]

Re: Need to change U joints on volvo/penta cobra SX outdrive??

Copy that, most likely I will replace the bellows. I have done everything else (impeller included) recommended in the periodic maintenance chart except pulling the drive. I am definitely one that believes in preventative maintenance.

I'm still not sure whether or not I'll use adhesive when I replace the bellows. If it's NOT RECOMMENDED, obviously I won't use it. If it's repairman's preference I'll probably use it for added security. From what it sounds like the bellows you pulled off wasn't an OEM part and therefore probably wasn't original to the drive and may have been installed by someone other than a professional VP service technician. I'm just curious what VP recommends and what the service techs do. I'm not trying to knock what you did or anything, and I do appreciate your advice. I guess I could try calling the local shop again.

Weekends here, and beautiful weather no less. I would love to start this thing but the yards got to be mowed along with everything else on the project list so I probably won't get to starting the outdrive carrier build till Tuesday. I'll post updates and try and include a drawing of it's construction once done. Thanks for your help.

 

[familyguy]

Re: Need to change U joints on volvo/penta cobra SX outdrive??

Built the carrier (I'll post pictures later) & pulled the drive, nothing glaring noted - no water in the bellows, no rust present on the u joints coupler and other stuff, u joints function smoothly without any obvious play, bellows flexible without evident cracking, gimbal bearing turnings very smoothly without catching/bumping..., just noted some runny broken down grease in the bottom of the bellows.

Okay, that doesn't explain the sound that started all this...so pop said take it to the shop. Right, so did and turned out to be a great idea. Two very helpful gents confirmed u joints look good, problem sounds to be trim pump related. Those go for about $500...yeah, I think I'll wait on that till it's necessary (it has plenty of fluid, it doesn't leak, drive doesn't drop by itself). They recommended just keeping an eye on it, and try and diagnose it further while out.

So I picked up a new u joint bellows, kept old exhaust one, got a new water pass through o ring & 2 new drive shaft yoke o rings, ordered the alignment tool online. Total cost: $141 plus extra for wood. Approximate time so far: 5 hours with majority spent building carrier.

Still hafta: Grease u joints, clean & regrease gimbal bearing, reinstall bellows (still not sure about adhesive), realign, then reinstall drive...

...THEN GO BOATING!!

 

[familyguy]

Re: Need to change U joints on volvo/penta cobra SX outdrive??

Here are the pictures of outdrive carrier. My dad gave me the premade castered base. I'm not sure where he got it but I know Harbor Freight & Tools has some similar ones, or you could make your own. The two 16" x 20" x 1" boards I screwed to this were cut from a 17" x 47" x 1" pine board I got from Home Depot in the nicer wood section. It seemed to help to have a real flat surface to screw everything to.

Regarding the adhesive...

...upon close inspection of the bellows attachment locations on the pivot housing and transom plate it looks like a very thin layer of old adhesive was applied. The old bellows is OEM, unknown if it's original to the boat or not, but if it is, that seal held up for 12 years (supposedly the boat was always garaged and he put less than 100 hours on it)...don't know if that's true or not...

...I don't care about the exhaust bellows being well sealed, just the u joint bellows...

 

[ENSIGN]

Re: Need to change U joints on volvo/penta cobra SX outdrive??

Sounds like you got a bad gimbal bearing.After you pull the drive reach in and turn the center of the bearing,ANY roughness or sign of water REPLACE IT.Your U joints don't have grease fittings and volvo penta recomends replacing the whole shaft.(which I think is bull) make sure the joints feel smooth when you work them sideways.You can remove the exaust bellows and sneak the driveshaft bellows out the bottom.Don't use bellows adhevisve.good luck,Ted