Carc oil seal

Came back from a Sunday ride & saw this;

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Oil stripes on the tyre

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The leak is from the bottom of the bevel box from behind the metal flange

View from the muffler side
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I imagine this is from the rear CARC seal , wasn't finding a photo essay on being able to replace just the seal. Pete has the bearing replacement thread but I'm hoping for a simpler & cheaper solution.

Advise & guidance would be appreciated.

Thanks

The parts diagram has;

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I'd pull the wheel off and make sure. If it's coming out of the holes for the line holder it would be different.

I used this as a guide when I did my Breva. I took the CARC off and put it on the bench. I was unable to prise the seal out as he did and resorted to gently drilling a small hole in it and inserting a self-tapper screw to lever it out.

Changing the Final Drive Seal

Breva CARC issues

Motoguzzimackers, thanks for that. Looks much more do-able that I was winding myself up into thinking it was.

Pretty straightforward. You can do it on the bike but it's easier on the bench and taking the bevelbox off allows you to check the forward pinion seal and slap a bit of grease on the rear splines.

Disconnect brake and torque arm and remove wheel and speedo sensor. Then undo the four bolts that retain the bevelbox to the swingarm. Post-2008 bikes will of had their bevelboxes glued on to the swingarm to prevent oil seepage from the front boot. This can make removing them a bit tricky. Either use a bottle jack between the shock linkage and the ABS sensor mount to lever it off or you can use judicious smiting with a dead blow or rubber hammer. I prefer the jack, Michael has a 'Touch' with the hammer that eludes me. I flail away and get nowhere, he just seems to give them a tap and they drop off! .

Once it's on the bench you should be able to get a lever under the lip of he seal and flip it out. Do be careful not to mark the surface the seal runs on. Once out check the bearing you can see beneath the seal carefully. Particularly it's cage. If any of the cage rivets look loose or appear to be missing or if the cage is deformed or broken that is the cause of the seal failure and the bearing needs replacing.

If the bearing is OK clean the boss the seal runs on and grease it thoroughly so the new seal lip doesn't hang up and gently tap it into place until it's outer face is flush with the case. Check as it goes in that the lip isn't hanging up.

Before you reassemble everything and refill with oil, remove the top hat breather and make sure it passes air, (Or better yet replace it with a remote breather!). Make sure you tighten the swingarm to bevelbox bolts sufficiently.

Go ride.

Thanks.  

The seal is ordered & I’ll report back what I find.

I just had the same oil leak on my GRiSO two weeks ago, it was pretty frustrating to see it. Instead of buying the off the shelf 74€ 85x110x8 seal from the only Guzzi dealer in town, I opted to order a 85x110x10 viton seal via SKF, costing me 18 something euros but it meant waiting 7 days for delivery. Adding to the costs were oil contaminated brake pads, but I changed the seal and brake pads in my driveway with very basic tools (car jack and lug nut wrench etc from my SAAB haha) in about 30 min.

MK1004,
Good to know, do you have a part no for the SKF seal ?

The same seal is used by some BMW 1100's. Costs a bit less than the Guzzi one but the aftermarket one in Viton will probably be fine. Both the Guzzi seal and the BMW ones are directional though.

So here's where I am.

Drained the oil which was a little dark but not too alarming, the magnetic drain plug had some filings on it

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Looking back through my records, whilst believing I'd at one time changed the oil, didn't see it recorded so I'm thinking blowing the oil seal is somewhat of a self inflicted wound  

With the rear wheel up I pulled & pushed on the tyre with hands at 3 & 9, nothing. Did the same again at 12 & 6 I could feel very slight movement.

Looking up the bearing the cost varied from $230 US to $360 ! I didn't have much success looking for the same bearing from an industrial supplier. Talked the situation over with my mechanic whose opinion  I respect. He confirmed that seals often leak because the bearing is deteriorating. But found it odd that I had any movement top & bottom but not left & right.

Pulled the seal & found no scouring , cleaning with q-tips I found some grey oil around the lower part of the bearing but hardly anything. Otherwise a clean intact bearing.

So I decided on installing the new seal & riding the bike. The summer is here & with the world spinning out of control at the moment I need the therapy that GRiSO allows.

Looking up SKF online I found a very informative website, describing their designs & products. By contrast I had 1/2 hour stumbling through Brembo's website with no useful result. Learnt that seals are ordered by a straightforward description of their size & properties so no part number is needed. Ordered a 85 x 110 x 12 HMSA10 RG.
Found a supplier 10 mins from my work & had the item in my hands the next day for $31-  

Using a knife to get under the inner lip of the seal , then dental picks & a screwdriver popped the seal off. Getting it back on I was having no luck tapping it in so rigged up a press of sorts using 2 x 4's, plywood 'plates' & woodworking clamps to evenly apply pressure to insert the seal, then tapping it flush afterwards.

Found I had some genuine Moto Guzzi 80W90 final drive oil on the shelf, sure was some dark stuff. If I'd have seen that come out of the CARC I would have been more concerned.

Started cleaning up the oil ring on the inner fender & then realised the oil was on one side of the brake rotor. Cleaned that off with lots of detergent & mineral spirits but feel that I should sand the disk with 150 grit or something. There's a thread on changing brake pads where Uzidit recommends re-conditioning the rotor this way.

Looking at the brake pads, one side is contaminated the other fine. But this lead to the waste of time on the Brembo site hoping for a description of their products & a further 2 hours at the local Bike Megastore unsuccessfully trying to find EBC pads. AF1 came through with a sintered pad set from Ferodo for $40 instead of the $88- OEM Brembo part

Comments, guidance, dire warnings. All appreciated

Ok, a couple of things here.

Firstly the oil discolouration. Whether or not this is *Normal* will depend on a couple of things. Firstly, how long it was since it was last changed. Secondly, the brand of oil used, (Some do tend to darken a bit over time but it should still drain out honey coloured unless you are using one of the oils with a dye in it, (Redline etc.). If it comes out cloudy? This is usually a sign of water intrusion. If it comes out sparkly? Start shitting yourself!

Your mechanic is correct in that severe darkening of the oil is usually a good sign that a bearing is going tits up. It is usually accompanied by a burnt smell which is detectable even over the usual unlovely stench of gear oil!. A seal blowing in this way in this location can quite often be the large crownwheel support bearing inboard of the seal failing and it is very difficult tp dtetect this without disassembling the box as you need to be able to get a really good squizz right down into the bottom of the ball tracks to see if any brinnelling is occurring.

Now the seal itself is another matter. The factory seal is I believe an 85x110x8 and is a directional seal which means it is designed to work most effectively when the shaft rotating through it turns in one direction. It is also manufactured in Viton, a far more pliable and heat resistant material than a standard Nitrile seal. Now the Guzzi seal is expensive but a similar seal with the dimensions of 85x110x10 is used for the same purpose for certain BMW's and this too is a directional seal and most importantly will still press in to the casing without using the outer edge of the bearing race as a register. While the seal with a depth of 12mm might still be OK my memory from a long time ago was that it was too deep and if pushed in far enough to be flush with the case it fouled somehow. Now I'm not suggesting you take this as gospel as my researches on the subject were done very early in the history of the CARC design so a good 14 years ago so I may of got that wrong. If I haven't though you will soon know as the seal will quickly fail again, it wont be dangerous but use caution.

What is more likely to happen though is if the seal is a non directional, nitrile, seal it simply won't last very long. A few weeks would be my guess but once again it's one of those 'How long is a piece of string' things as it will depend on heat, how hard and how often it is used and heat cycled.

The movement in the bearing when rocking the wheel is an indicator of little consequence. The big bearing has a C3 clearance which will of course be multiplied in terms of movement by the time it reaches the wheel rim. While it should be uniform the simple fact is that this odd anomaly of not only inconsistent play but also it's complete absence on some assemblies while it is clearly noted on others is something that has evoked reactions varying from head scratching to full blown pearl clutching hysteria on various forums but the bottom line is that in and of itself it doesn't seem to matter and is not a critical indicator of impending failure so? Watch and periodically check. If it deteriorates then red-flag it and fix it.

One final thing. It is probably worth at this time dropping the CARC unit off the swingarm and checking for oil in the swingarm and seal carrier that surrounds the pinion shaft. If there is an abundance of oil there it is often an indicator that the seal has gone and the usual cause of that is that the nut that holds the pinion bearings under preload is coming loose. This too can provoke crownwheel seal failure although I hasten to add that in your case I do not think this is likely, either as a cause or an outcome.

Pete,
You've given me some encouragement;

The oil came out obviously clear and a darker golden color but still regular oil color with no smell & no sparkles either.

The seal is probally going to be a try it & see situation. I measured that there was 12 mm of clearance from the casing to the ball bearing cage, it had 0.5 mm to go so I endeavored not to drive the seal below the casing .
The compound is a nitrile rubber material, there were no instructions with the seal as to direction or installation.

The play in the wheel was the strongest case for the bearing replacement, I'll take your explanation and watch out for any changes.

All in all I'll keep an eye on the seal & the rear wheel generally as much for material failure and an incorrect installation.

Do you have a recommendation about cleaning or sanding the brake rotor because of the oil or the pad material change ?

Cheers

I'd just give it a really good scrub with brake cleaner and fit new pads. I think EBC FA 181-HH are the number for the rear. FA 244-HH for the front.

Hey there, you're having your share of GRiSO fun.

Try MG Cycle for brake pads, where I got my EBC's from.
Real easy to remember MGCycle.com. They're an independent Guzzi parts outfit.
Most all the Indiana guys get their parts from them, I can personally recommend their service.
No Guzzi dealer close by, except maybe Cadre but it's a four hour round trip for me.

If you need a extra pair of hands or just want someone to come over and drink all your beer just let me know

Thanks Colt

MG Cycle, Their site was down for maintenance when I was shopping....

Hey if this seal doesn't work out & I do need a bearing  I'll put the GRiSO in the van & bring the beer to you

The big bearing is a 61917-C3. I always buy ones made by FAG in Germany because they seem to have the most robust cage. Note the bearing must have 19 balls. There are other, inferior, versions of the bearing that are dimensionally identical and carry the same number that have only 17 balls. These are to be avoided at all costs.

Thanks
That gives me something to shop for

Nobleswood wrote:

Thanks Colt

MG Cycle, Their site was down for maintenance when I was shopping....

Hey if this seal doesn't work out & I do need a bearing  I'll put the GRiSO in the van & bring the beer to you

I'm about two hours from either one of you. I like beer too.............

Sounds good Tim

I sure if we pour enough beer on it, it'll be fine.

Rick, extra hands are always welcome.

Have to see what's involved with the bearing replacement.
My shop at home isn't as well appointed as the engine shop at work.
Still we should be able to get something going.

I thought I saw a write up on the bearing replacement here, or there, or somewhere.
Have to look. Hope the bearing is fine and the seal does the job.

Oh, and if you want to see what happened to the shithouse 17 ball bearings they originally used?

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That's scary to imagine that happening at speed

Yikes!

More worriesome would be the oil on the back tyre when the bits of the cage get pushed through the seal. Long before the bearing could collapse the bike would be effectively unrideable. Anyone who has had the misfortune to get oil on their back tyre will tell you that the first time you pitch it into a corner you are told in no uncertain terns that 'Something is up!'. If you're lucky you don't crash, just slither to a halt and empty yer panties!

For the bearing to collapse all the balls need to be able to migrate to one side of the race and until the entire cage has disintegrated and been expelled this is unlikely to occur. At least not in a timeframe of seconds or even, at a guess, a minute or two. Even if it did there is still the fail-safe of the outer, smaller, bearing which would retain sufficient integrity for enough time for the machine to come to a halt in most situations.

In reality a failure like this is catastrophic but it's not in and of itself likely to be lethal as long as the owner of the vehicle has a half a brain. The problem is a lot of people nowadays DON'T seem to have half a brain and when faced with such a situation, especially on a machine under warranty, seem to take the view that "I've bought this thing and it's not right so I'll ride it until it's properly, irredeemably, broken and then I'll wail about how shitty it is on Facebook! That'll show them!". When they try that trick with a failure like that? Well, they're in for a world of pain, and to be honest I have a very hard time drumming up any sympathy. If you're old enough to get a licence to drive a vehicle four year old tantrums should, really, be a thing of the past......

Final report;

Got out for a ride of 215 miles & so far all looks as it should. No leaks

Thanks for the advise & guidance.