348 flywheel rebuild

Good morning all, and a special thanks to those who helped with advice on my rebuild of the 348 flywheel. I needed this quickly and got the help I needed to get back on track, thanks.

I thought I would add a couple of points to the knowledge base on these rebuilds in addition to the excellent info on the348 . com tech site.

My grease had turned to something akin to water, not only is it 16 years old of course, but as I use the car on track and often heat the rears before starts it is also subject to a bit more heat than the norm. see pic 1 for a before. Here the grease seemed to have free travel over the central shiny area, that should be clean, and out through the central bearings.

With regard to the rebuild, as has been mentioned, Ferrari see this as a replacement rather than a service item and you can guess the cost of a new one! But the instructions (ref above) about getting it apart are great.

Getting it off, don't fart around, get access to the biggest gun you can to break that rear bolt. Its tighter than a (insert your favourite something very tight analogy here) and needs power. Also needed when putting back together. Don't even think a breaker bar will work no matter how long etc. save time and get or hire the biggest gun you can!

Once opened - The care needs to be taken in looking at which way round the springs and plastic carriers are, there are 2 types of end piece and I kept those in the same slots. There is also the small square pieces with spring in middle, these have a chamfer on them, I replaced these with the chamfer pointing to the sides, they did have a wear mark on them on one side, but not sure which, assumed outside and replaced in pointing towards middle on inside.

See pic 2.

Then there are the service bits. Each bolt has an o ring top and bottom. The large flywheel insert piece also has a big o ring going right around the outside. These need to be heat resistant of course so I replaced with viton ones. I can send UK source if anyone wants a set. Big one was (in metric) 230 x 3mm. this is internal diameter by thickness. The bolt ones I used 8 x 1.5 in the end, I think the originals were 1.55 but I could only get 1.5 or 1.6, so got both and preferred fit of 1.5s. Worked so far anyway. I have a spare set if anyone is interested. Indeed think I will suggest this all as a service kit to someone!

The grease has to be high heat as well of course. The original is kluber and I know Daniel has some for sale in the US. I bought a high heat from demon tweeks here in the uk. Redline CV2 which is good to 900 deg F melting point, synthetic grease with molybdenum. The 397g jar is more than enough http://www.demon-tweeks.co.uk/products/ProductDetail.asp?cls=MSPORT&pcode=RED80401 .

Lesson learnt with grease

DO not grease up as I did here with grease in central area. This is not good, not only does it make tightening bolts difficult as it tries to squeeze it all out the place it comes out is through the central bearings again. So just on springs etc round edges!! I wont say how I know this apart from I can now get a clutch out in this car is 40 minutes flat!


There are bearings front and back in the flywheel. There is also another one inside. The front and back are both SKF bearings part nos 3208 A 2RS2TN9/C3VT113 and the smaller one 6006-2RS1/C3 both available from Ferrari, the small one under £10 but I'm sure larger cheaper elsewhere as that was £70 odd I think.

Internal bearing, there is another small one inside, this wasn’t a skf. Is not available from Ferrari, I didn't replace this one and as I was in a hurry I didn’t take down the part number sorry, if anyone has it please let me know so I can try to source for next time!

The only other item that could / should be replaced inside the flywheel is what looks like a large nylon circular seal. Embedded in one side. Easy to get out, again I didn’t have time to source this one, it looked ok and has held out so far so left alone this time. Again if anyone has a source let me know please.

Getting it back together, followed the instructions easy. Espec like the trick with the pencils.

I torqued the flywheel bolts up to 35 ft pds. In the absence of any other figure.
I also got the flywheel skimmed whilst it was out, took a bit off, my local bloke who does this for me said it was the hardest thing he had seen, took 3.5 hrs under water to do! He also relined my clutch plates (again) as the grease had done their worst. Got the flywheel done for £75 and both plates for £60.

I then got fastest 0-64 ft time this weekend at 2.35 secs so works as well!

Thanks all again, happy flywheels to you all.
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Of course I will, initial look when I had to reopen it was that it had held together well spaced out nicely around the wheel from the springs to edge. That was after a day of starts on a hill climb (about 15) with a few burn outs to warm etc. plus logn drives up and down there. now i know nothing like several years work, although some would say my driving for a day is equivalent to an ordinary year!

I THINK it is a weight saving thing. Gives the same effect as a heavier flywheel but 1/2 the weight (from memory rather than figures). The 355 is I think similar.


Interestingly, the advice I got from one independent repairer was they just pump some new grease in through the back to replace that lost with the saying yes it will continue to leak! I would certainly not be happy with that.