348 Main , Layshaft disassemble

You have to bang it out, unless you have access to a nice big press.

When I took mine apart at fatbillybob's house he had a bunch of metal pieces that we had to hold inside the gearbox to keep the center bearings in place. Then we put a cap on the end of the shaft, with a piece of delrin/plastic inside it, and I banged it out with a sledge hammer.

I dunno if fat boy has any pics of the procedure?

If you have a big press that would work better, but you will still need some way of keeping that center bearing in place so you can bang/press the shaft out of the center race.

 

One more thing I forgot.

If you are looking at the front of the gear box, that's the side that attaches to the back of the engine, it gets pressed/banged out to the left.

Hit up the fat man, or even plugzit, and see what else they have to add.

 

And,

How come you have to remove the main and lay shaft?

 

You hammer on the oil pump side out towards the other end.

As I was saying, fatbillybob had some metal bits that we placed inside the gearbox to hold the bearing in place. We wedged them between the gearbox housing and the bearing race. If you look inside the gearbox you will see some small retainers on either side of the bearings. The retainers are screwed to the gearbox housing via a allen screw. Those retainers are not capable of withstanding the impact of the sledge hammer hitting the shafts. They will bend/break. But they only hold the outer race to the housing, it's the inner bearing race that needs to come off. But, you need to hold them both still. You have to keep the bearings in place so that as you are banging on the shaft it will be getting pushed out of the bearing. The bearing cannot be allowed to move from it's position in the center of the gearbox. The main thing is to keep the center race, that's the part pressed onto the shaft, from moving, you want to hold the race still while you are pressing/banging out the shaft. So what you are going to have to do is figure out how you can wedge some solid pieces of metal, plastic, wood, pipe, or whatever will work to hold the bearing in place.

 

Forgot something.

Before you go trying to get the shaft off the bearing you need to remove the differential. If you haven't removed the differential you'll need to do that first.

 

Here Samy,

Have a look at some of the pictures in this thread http://ferrarichat.com/forum/showthread.php?t=77427 you'll see the retainers I'm talking about on page 5.

 

Yup.

The roller bearings will fly all over the place.

I'm guessing you are only going to change the ring and pinion gear and not the bearing? I changed out all the bearings when I did mine rebuild.

If you are going to do it that way what you will need to do is, secure the roller bearings in place with Ferrari especial tool #96 (a rubber band). Here is a picture of it here. http://ferrarichat.com/forum/showpost.php?p=135948915&postcount=2 Get the shaft started out, but not all the way. The put "ferrari especial tool" #96 over the bearings. LOL! That way when you take the shaft out all the way they roller bearings don't go everywhere and stay on the inner race.

 

Nope you don't have to remove the ring gear, the differential will come out in one piece.

Hold on let me see if I can if my old post on how I describe getting it out.

 

Found it!

Here is the link to that thread http://ferrarichat.com/forum/showthread.php?t=102751

Now I remember better. Okay here is how the differentials comes out.

Remove both of the hub shafts from the differential. Those are the parts that the inner cv joints get bolted to.
Then remove the cups for the differential bearings on the sides of the gearbox.
Next remove the bearing from the oil pump side of the differential.
Now rotate the differential so that the ring gear is facing out, towards the open/front of the gearbox. You want the oil pump side of the diff to go inside the gearbox (towards the clutch) and the ring gear towards the open face of the tranny.

The diff will come out. You just have to rotate it ever so slightly to get it positioned just right to come out in one piece. Don't get frustrated it does come out in one piece.

 

Why with a bearing puller of course.

Once you have the bearing cups off, and the bearings, you'll be able to move the diff just enough to get it out. But you have to have the cups and bearings off to do it.

 

The gear box is made by ZF (Zahnradfabrik Friedrichshafen) not Ferrari, and since they are a Deutsch company maybe you'll have some luck with getting a new ring and pinion set directly from them? Soon as you get your pinion gear out have a look at the manufacture number stamped on it and give them a call. I would imagine that the same type ring and pinion set is used in some other automotive application, as I found out the majority of Ferrari's stuff is. So you may be able to get it at a big time discount, that and they seem to be listed as "unobtainium" by Ferrari. So give that a shot and see what happens?

 

On second thought forget about the manufacture number. I dug out my old bevel/pinion gear to have a look at the number, it's just has a hand scribed number, which seems to have been done by whomever put the transmission together. Anyway you can see how my gear was completely gone, and mine is the old 10 spline like yours.
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OOOOOOOOH SNAP!!!

Yeah that thing is broken alright, and I think we are talking about a completely different gear? Is that the transfer gear that is behind the slave cylinder?

 

Sorry about your misfortune but people talk about upgrading their 348 box with 355 small spline shafts. It is obvious that this did not help you. In fact yours is the biggest transfer gear explosion I have ever seen. You will need to rebuilt the entire box.
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YES! but the gears must be paired. Use a new 25/27 for example not a new 25 and an old 27. You know what I mean? The WSM has the available ratios. For a streetcar there is little difference. You can get a bit more gas mileage and lower RPM at speed at one end of the spectrum or an imperceptable amount of extra acceleration with the other extreme.