1998 550 Maranello "sorting" thread--DIY

Weird about wp. Problem is when people do not use a tool. The issue is the relative positions of the seal lip, inner ring thing of the seal, and the shaft. If that is not right you get leaking between tue ceramic discs or you get binding at the ceramic discs and it will not turn resistance free. So the tool gets the right pressure on the ceramic discs while seating the outter ring of seal to right depth. Knowing that the tools should bring seal home with zero thought while using some sockets will do the same thing but you have to set depths so the shaft spins free yet ceramics seal. I guess that was clear as mud.

 

Pete-Is that the reason you pulled the Timing Cover...to check the bearings?

 

Pete,

Hill's bearing has been coming for over a year. It ain't coming any time soon as far as I can tell. I would just use the FNA replacement and just consider it on the to be replaced list for your next major. And Can't you feel a lot of that play by shaking the cogs even if the gilmer gear teeth are engaged with cover on car? My 2000 (65k miles now sold) and 2001 (22kmiles) 550's are still on the original bearings the motor came with. How come some of these cars seem to eat these bearings the first time? I get that the replacement bearing are junk.

Also John has a non-OEM untested modification of the case and different bearing that will work if you want it correct now and can live with life outside the Ferrari parts chain. I trust John more than Ferrari.

 

Thought this is worth mentioning if you're referring to Pete's great tutorial, like I did, in fixing your V-12 ... it ain't always that easy... See post # 7 in:

http://www.ferrarichat.com/forum/456-550-575-sponsored-bradan/458864-456-front-cover-gasket-t-belt-replacement-cam-timing.html

Regards......Mark

 

We haven't publicised this because it's not yet tested, but MSW worked with SKF in 2013 and 2014 to retro-engineer the outboard bearing system for these timing gears, since the original SKF bearings are NLA. (In fact, SKF advised us they'd reached EOL in 2010, and any bearings purchased after that were NOS, which explains why some have looked a bit rusty and have been known to throw grease.)

We took a slightly different approach than Paul (Hill Engineering), to see what we'd have to modify on the Ferrari side in order to fit a different, but standard size bearing, and it was pretty simple, really. (AFAIK, Paul has taken the approach of trying to find a bearing manufacturer to reproduce the original SKF bearing, which is a far bigger challenge for the potential very low volume of bearings required.) By taking around a mm off the seating surface for the bearing on the cam gear shafts, then by using special, thinner snap rings, we were able to accomplish it, and SKF had a standard, very common bearing they recommended that we use for the application, which is in no danger of going EOL anytime soon. So, no case modifications, and only a slight mod to the cam gear shafts, and we now have a bearing that is about 2.3mm wider than the original and better able to handle the radial loads. But....as I mentioned above, it's also untested.

 

Hi

The position of the seal is very important.
I remind, that the seal should sit equal with the passage, where the square starts.
Pressing on the seal more than in this position causes a rough and strong run.

Hope it helps.


Daniel

 

That is extremely disappointing which means you have to take the cover with gilmer gears off to see if the bearing is toast because the gears hold everything well enough to fool you when all engaged.

It is very possible that this gear death is much more common than we think. In my major just a few months old I just shook that timing cog real hard felt no play and called it good. That could be a big mistake. DANG!

So add that cover pulling to every major now unless you have the JohnC conversion. That bearing in your video is toast and must be changed. If John has done the math on cutting the gear shaft down to make sure it is strong enough to go the distance without anything weird introduced like stress risers I think that is the way to go. Several Ferraris use that bearing yet there is no decent replacement and no replacement in site as far as I can tell.

 

Pete, it's apparent the bearing is in the process of failing due to the radial side loads, which is disappointing, considering you've only put 4000 miles on it. When we were working with SKF last year on this, and I explained the application to them, they allowed that this isn't the bearing they would have recommended for this application, but they were not involved in the early process of spec'ing it; only later when Ferrari told them what they wanted with the options for sealing, etc. Of course the design trail for this bearing is rather murky as it's 20 years old, and we only heard one side of it.

As you may know this bearing has been used in this application for several generations of Ferrari models as far back as the 348, so perhaps they thought, "well it's worked OK in the V8's, so it should be good for these models." However, our engine family, the 456/550/575/612 were the first time this bearing was used in a V12 application, as all prior applications were on the V8's.

Perhaps Brian could comment on whether our V12's run substantially higher belt tensions than the earlier V8's? Certainly the load on a pair of camshafts driving 24 valves, instead of 16 per bank is going to be greater - perhaps by 50%? Did Ferrari take this into account when they decided to reuse this same bearing?

I think your only viable option at this point is to buy & install the no-name bearings from your friendly Ferrari dealer and monitor them closely.

I'd love to be able to recommend our solution to you, but I can't & won't until it's tested. On paper, it's a better solution than the original Ferrari bearing because it addresses exactly the problem you're having.

 

Agreed but if my choice was to take a change on John's mod or the known failing bearings I would take my chances with John. So the bearing that came in the car from factory was better than the skf replacement? Or there are a bunch of failed bearings out there? Or only the replacements are bad? Or the bearing as speced is guaranteed failure?

 

Has this been a problem? Have not read about any failures on the original bearings.

 

Carl, lots of questions there, and I think maybe there's a mixup in who provided what:

The bearing that originally came in the car from the Ferrari factory is/was an SKF. SKF discontinued making this bearing in 2010. Any bearings that have been purchased since then have been NOS.

Maybe not failed, but they're certainly not getting any healthier.

Ferrari are now sourcing this bearing from an unknown vendor. There's speculation it's Chinese, and there's also speculation it's from a little bearing manufacturer in Italy that no one's ever heard of. Regardless, there's no identifying marks on the new bearing to show who made it or where it's from.

All bearings will fail eventually. The more side load you put on them, the faster they'll fail. This bearing, as built, probably gave acceptable life for the V8 cars. Would I use the very same bearing for the V12's? Probably not, unless I ran the numbers and found that it was way overdesigned, or I could get more creative with the belt tensioning setup.

 

Who has SKF NOS bearings? I thought they were all gone and only the no namers were available.

In Pete's case I thought he replaced with NOS SKF which have now failed?

Also, there was some talk that the specs for belt tension are all wacky for the 550. It seems like pros have their own closely kept freq readings for this tension and there is variation there even if someone tells you the trick number how they get it and how they pluck the guitar string makes a difference. That is a lot of why I just don't bother and do it all wrong tensioning by hand and experience. If Pete has the NOS SKF bearing what roll does or did proper or improper belt tension play? Of course Pete I hold you in the highest regard and not implying anything wrong during installation but just as an important part of the discussion.

 

Carl, I think the NOS SKF's are all gone now. Pretty sure the ones Pete put in his car last time were some of the last ones.

Just FYI, here's a comparison of the specs for the bearing we're going to be testing (as recommended by SKF for this application) vs the original that SKF discontinued:

As you can see, the new bearing is 19% wider than the old, which helps the side load capability tremendously, and it's a dual row angular contact type, instead of single row, deep groove, like the original design. There's no need to preload this type as there was with the old, and its radial load carrying capability is greatly increased, as is its axial. In fact, as you can see from the chart, the overall dynamic load capability is 48% higher than the old, and the static is 87% higher.

Dave & I saw this situation developing back in early 2012 when people began having problems with the "no name" tensioner bearings (171057) that Ferrari started sourcing in lieu of the higher quality SKF (Note: Daniel @ Ricambi still sells only the higher quality SKF version of the 171057, however he sources them through Paul Hill, NOT Ferrari, which is one reason why his price on this bearing is probably double or triple what others charge, because they're sourcing the "no-name" bearings.)

MSW began brainstorming how we could adapt the Ferrari timing system to use a more standard bearing, and improve the system while we were at it. After a lot of consulting with SKF and experimenting, we came up with this bearing, and the mod for the cam gears. What we/I didn't anticipate, was having to completely rebuild my engine, for what started out as a cam belt change, and that it would be down this long. Else this solution would have been tested, proven & available to the community long before now.
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It really does not seem like many fail with the originally installed bearings as delivered. Either that is true or the entire fleet is running around on bad bearings and we just don't know it. No body pulls the timing cover to see. I would think that if the later we would see many more blow up motors.

When you changed for 1st set of bearings how did you find that 1st problem and did that bearing with more time and miles wiggle as much as the 5 year old 4000mil failed bearing of today?

 

By law the manufactures are obligated to make parts for 10 years for there cars, and our cars are past that legal limits. We may face more and more of similar issues from here on considering no after market parts avilable.

 

Not to worry, with ever improving CNC and 3D printing technology, aftermarket will grow once there is enough demand.

I think it is the opposite, parts and solutions will get easier.

It is definitively the case in the older Mercedes W113 (Pagoda) - I can get virtually any part, and they are getting very cheap as well.

Same goes for the Ferrari 250 - many manufacturers are making parts.

 

Pete you make some good points.

The "reported" bearing failures to date (and from memory) have consisted of a couple of cases for both the tensioner and this outer cam gear bearing. But surely there have been some undocumented successes with them, too? Not everyone who changes these things necessarily posts about it on FChat.

Remember that these same bearings are also used in the very same application for the 348's, the 355's, and the 360's, and even the Challenge versions of these cars, and we don't hear those guys squawking about them? (Or maybe they are - I don't visit the V8 section of the Forum?) So surely some other owners have been changing them and having success?

So I agree with you on proceeding with a set of the no-name bearings; it's your only option at this point. Just keep an eye on them.

Just as a point of interest, below is a partial cut & paste of the drawing SKF provided us of the "old" bearings they made for Ferrari for this application. The engineer I worked with commented on the unusual design in that the race was offset within the housing, and one side had a special high temperature garter seal, in lieu of their standard seal, and he opined that this was to help prevent oil contamination/dilution of the grease from the engine side. So, bottomline, this bearing didn't have a universal fitment, but should have been installed with this garter seal toward the engine.

I wonder how many of us, including the pros, would have been aware of this? I've looked at these bearings in the past, and noticed they weren't symmetrical from front to back and wondered why, but didn't think to question anyone, and doubt anyone other than SKF would've known anyway.

Pete, it would be interesting to know which way these bearings were put into your front cover, and when they come out, it would also be interesting to know how much grease is left in them if you wouldn't mind popping their seals?
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