348 Clutch Release Bearing

I have entered the clutch-flywheel area for the first time, mainly with the intention to replace the grease. However, I have to also fix the clutch slave cylinder. I have had no fluid leak at all but I noticed that the scraper ring lip is gone (there is only about one quarter of it left) so I'll be taking out the slave. The release bearing feels very good, turning easy and sweet, but I might decide to replace it together with the scraper and the seals.

I have a few questions (my car is early 1991 348, twin clutch):

1. First pic, the existing slave/bearing assembly - is this the second generation unit, i.e. an upgrade by the factory? is this a reliable solution or was there any subsequent further factory upgrade?

2. How easy/difficult it is to extract the bearing from the housing and to insert a new one?

3. Second & Third pics, the new bearing I bought before I checked what I have - is this for the first generation slave cylinder? (the existing bearing uses its inner race to push on the clutch fingers, the new one uses the outer race)

4. The new bearing is from Superformance, 55 mm ID; Superformance also offer similar bearing with 50 mm ID; which ID is correct for my existing type of slave cylinder?
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That should be all one piece.

I don't think the bearing is separate.

 

From the looks of it you do not have the factory upgraded unit. You have the cast steel housing which is prone to leaks from the seals as well as the housing is prone to catastrophic failure from cracking. The factory upgraded unit (from what I recall and my own service records) is aluminum, but still no prize. I certainly would not spend money on the factory "upgraded" unit over the aftermarket solution. Anyway, I hope this helps.

 

Thanks. There appear to be two types of cast iron slave cylinders: 1. As shown on my picture where the thrust bearing goes INTO to slave cylinder and the bearing's inner race, via the special insert, acts on the clutch fingers and 2. A type of slave cylinder where the thrust bearing goes ONTO the slave and the bearing's outer race, via a special cone adapter, acts on the clutch fingers. It seems that the second type was later replaced with a similar cylinder but made of aluminium. Is this correct?

I will continue using my existing slave assembly (as pictured) after replacing the two seals and the scraper ring as its condition is still very good (13k miles). If I decide (or have) to replace it one day, I will certainly go for the Hill Eng's solution.

 

Hi, I have replaced my clutch bearing seals a few months ago.

I have a 1992 - 348.

You have the old housing. Not the upgraded one. Mine upgraded one, doesn't have a bearing inside. Just the 4 green/blue seals.

Clutch Parts for Ferrari 355 - Superformance

The early 348 and 355 have the old housing, the later 348 and 355 have the upgraded one.

The seals and scraper ring aren't that hard to replace. you can boil them to make them a little bit softer for replacement. Make sure you take a look how the scraper ring is mounted! I forgot how it was mounted.

 

I just took apart my clutch slave/bearing assembly. Very easy in the case of the type of the cast iron slave cylinder that I have which was the first upgrade (the release bearing sits inside the "cup" of the slave). There are two 5.5 mm dia. holes at the back of the cup, below the spring "ears", which correspond with the bearing's outer race. Gentle tap with a hammer on the drift, alternating the holes, and the bearing came out nice and easy. I was holding the slave in my hand while doing this.

The diagram below the pic. of my slave cylinder shows the "cup type" at the top and the earlier "obsolete" (superata - superseded) type, also cast iron I believe, with the release bearing sitting over the cylinder (and not separately available). It appears that Ferrari later introduced an aluminium slave which was in the shape of the "obsolete" type. One has to be careful when ordering the rear slave cylinder seal - it is not same for the two types (35 & 44 on the diagram).
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I recently rebuilt mine (also a cast iron one) including fitting a new bearing. I sourced all parts locally after being sent incorrect sized seals from superformance. U will need a new u-seal, quad ring seal and scraper seal. I Also had to have the inner race of the bearing machined out to fit the ring the pushes on the pressure plate springs.

What i have now is a leak free TOB.

 

Thanks for the info especially on the bearing machining. I thought the special ring was just pressed into the inner race (haven't yet come to extracting the ring).

 

Hi Christof,

It looks like my clutch release bearing (SKF BB1B631107) has the ring that pushes on the pressure plate fingers as an integral part of the inner race. I don't see any sign/line that would suggest the the ring is pressed into the bearing (machined) inner race. Was the ring removable from your release bearing?
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Ok, sorry to hijack thread. My driving season experimented a hault when my release bearing body cracked. Is it a known problem and is there a good solution to fix it?
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Yes, a common problem with the old OE components.

Go with replacements from Hill Engineering instead. Best to use both parts.

Here's mine:
.
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This is what I did on my 91 when the TO bearing housing got messed up. I think it was $600 for the whole setup with the new flange and housing w/ bearing. Nice quality stuff and I doubt I'll ever have to worry about it again.

 

Ok, anyone have a guess what causes that lip to break? Or is it just matter of fluid pressure affecting those seals and at somepoint lip breaks? It happened without any warnings and pedal went loose instantly

 

I had this happen last night. Clutch to floor instantly. Looks like the Hill Engineering solution the best. Other options?

 

It does happen, but there's no solution other than to replace it.

 

Hill is a good choice

 

Mike is right. The Hill parts are pieces of art in comparison to the original parts. I replaced the various seals in my factory throw out bearing a few times but the leaks would return. Two or three years ago I installed the Hill parts and have had no issues since. My pumpkin was apart recently to rebuild the flywheel and the Hill parts still looked new.

 

@Berning - We have the Hill release bearings in stock, and you'd have it for the weekend if you ordered tomorrow or Thursday:

https://www.ricambiamerica.com/crb355ms-348-f355-clutch-release-bearing-168594.html

 

Thanks. looks like I need the flange and bearing kit. Correct?

Daniel, I am sure I will be in touch soon. Need to order wheel spacers as well.

 

Not necessarily. Once you have the clutch pumpkin open, you'll know whether your car has the older cast looking bearing, or the newer F355 style fitted. It sounds like your car has a bunch of upgrades/mods, so its definitely worth inspecting before placing an order for potentially incorrect parts. You may simply need the bearing alone.

 

Hi y'all,
I'm in the process of replacing the CRB, with the one I pulled out being dry, rusty, worn and beginning to split. Although my car (recently acquired) is a 1994 Spider ex UK, the gearbox/clutch assembly may be an earlier vintage, and in case relevant, the gearbox numbers I found are:
2135099 (cast proud), 141685 (stamped), and 7011 (cast submerged)

A HE Clutch Release Bearing (CRB348/355 MS #168594) is definitely required. However, I can find no discernable wear on the flange, which is an early style with the centres of the spring holes being 82mm apart, instead of 86mm as per the later style flange. Is there any reason why the spring holes of the existing flange cannot be machined 2mm further away each side (total 4mm), to match the spring hole spacing of the new CRB? There appears to be ample metal available to allow this.

Or are some of the other dimensions (i.e. t/o bearing I.D.?) different, which means the new CRB won't fit on the 82mm flange, even with new spring holes? Look forward to your thoughts!

 

I did it this on my GTB
Kept the original flange
Make the new holes 1mm deeper so the spring stays there

The old CRB can be fitted with new seals and also the bearing is sold by SF
The HE one is the better but most expensive option
If you choose to reuse the old CRB look for the
old thread where they say the Quad ring is the wrong size (Cauff)
I did this in my TS and months later all is good

 

I did the same:

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Didn't go deeper with the new machining but, if you do, you can always insert washers of suitable thickness in the spring pockets on the HE CRB if you wish to compensate.

 

Thanks Frank. I like your suggestion of a 1mm deeper hole to keep the springs in their new positions... I see there is plenty of meat underneath to allow that. The existing CRB is absolutely shot so I'll get a new HE unit, but as I say, the flange appears to be in good order so I'll be re-using that.

 

Thanks Miro... good suggestion! Photo below will explain why it needs a birthday Bearing was dry as a bone, and rattled back and forth by 3mm

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