ALFAGTV6.COM

Mats · Post by **Mats** » Sun Jul 30, 2006 2:19 pm

Part one, speedgears.
(This is where I show a lot of pics and set you up for a big cliffhanger...)

Have been working on a new Gearbox for the GTV for a while now, finally the bits are back together and ready for assembly. This puppy is a new 4.56:1 pinion and ring gear + used 75 speedgears and LSD. Decided to make a "good one" and actually bought three brand new synchro rings. Very nice, went on the second, third and fourth gear, i.e. the ones you might downshift to in a race.

Got some pics too, click them to enlarge.

New ring gear and pinion...

Just making sure... Yep, it's kosher...

Since the new pinion didn't come with a bearing I had to take one from another box I had laying around. I had tried to buy a new one but all I got was "No longer available".
Did a handy tool for pressing the locking ring off, discovered later I also needed one to press the bearing off (and on of course)

Interesting to see the difference between a non-LSD pinion (to the left) and a LSD pinion (to the right), quite obvious why you can't just mix and match even if both are the right number of teeth (41:10 for instance, which is available both as LSD and non-LSD)

Pressing the bearing home onto the new shaft

First two are the speedgears.

Reverse and fifth in case someone cares...

1-2 gears, note the immaculate dog teeth on the second gear. Switched the ring over from a fifth gear from another box.

3-4 gears, yes there is pieces of paper on the fourth gears dogs.

Questions?
Comments?

pancho · Post by **pancho** » Sun Jul 30, 2006 3:52 pm

I wish I understood how the GB internals work.

looks like a clean and professional job mats ! congrats.

zambon · Post by **zambon** » Sun Jul 30, 2006 6:19 pm

Wow

I didnt know you could still obtain new ring and pinion sets in 4.56 ratio!
That is going to be a very mean box on the track. Do you mind telling how much a new ring and pinion set costs?

Daniel · Post by **Daniel** » Sun Jul 30, 2006 6:21 pm

Looks great Mats, I did similar thing on the TS box for my GTV. Took good dogs etc from other boxes and built one good box. Should have taken detailed pics like you did.
I always thought you could use unmatched diff ring and pinion as long as you lapped them together and set the distances / preload correctly. Never tried it though, has anyone out there given it a go ?

Mats · Post by **Mats** » Sun Jul 30, 2006 9:01 pm

pancho: I'll write up a summary later, gotta go to the track in about five minutes.

zambon: Well, you can't buy new stuff actually. Since it can never hurt to ask I asked my local dealer if they maybe had a source for the stuff and it turned out thay had a customer way, way back in the day that ordered it but never picked it up so they have had this stuff laying around in a corner...

daniel: You can take mix and match between the same type of components, i.e. you can use a 75 TS ring gear in another 75 TS box if you set the pinion height and backlash correctly but you can't use a 4.3 ring gear with a 4.1 pinion no matter how much you adjust even if they do both have a 10 cog pinion.

Thanks for the comments.

Oh, btw. Part two will be me setting up the differential including pinion height and backlash and some other rather interesting stuff.

Barry · Post by **Barry** » Sun Jul 30, 2006 10:18 pm

Oh Mats,I miss that terrible gearbox oil smell with those pics!

See if you can get a virtual smell posted..of the oil dude,of the oil...

I see the box is an early one,the centering damper on the shift linkage..Must say,never noticed the thicker ls and thinner non ls gear set before...then again we never got ls boxes here..the only ones are adapted 105 to 116 ls units..and of course a very few 75ls boxes of late..

Micke · Post by **Micke** » Sun Jul 30, 2006 11:39 pm

I just swapped a 4.56 in my TS as well. Here's a picture where you see the size difference.

Maurizio · Post by **Maurizio** » Mon Jul 31, 2006 12:04 am

always thought it had te be possible to convert a 1.6 box to lsd
Just have to finding a 1.6 box for little money.......

Mats, do we get a nice folllow up with clearance specs etc

LENZ · Post by **LENZ** » Mon Jul 31, 2006 9:30 am

Mats where did you buy the ring/pignon ?
wanted to buy one for my 1.6 box but I was told AR no longer had any on stock.

Mats · Post by **Mats** » Mon Jul 31, 2006 11:16 am

M: Yes, there will also be a .dxf of the spacer I use. The whole enchilada for free, all included.

L: As I said, someone ordered it 15 years ago and never collected and has been sitting on a shelf ever since. No idea where to find one today, a scrapyard in Italy maybe.

Mezevenf · Post by **Mezevenf** » Mon Jul 31, 2006 2:27 pm

Nice detailed pictures

My poor modem

x-rad · Post by **x-rad** » Mon Jul 31, 2006 5:08 pm

MATS:

So that's what nice sharp dog teeth look like!

Nice work with the home made tools...look like Alfa tools

How did you calculate the pinion spacer depth with a new gear set?

zambon · Post by **zambon** » Mon Jul 31, 2006 6:16 pm

Mats,
Did you make your own dog gear puller tool? Are the dog gears easy to remove with a press?

Mats · Post by **Mats** » Tue Aug 01, 2006 12:43 am

x: I use engineers blue on the ring gear to get the pinion height and backlash correct, I will post pics soon.

z: I use a stainless knife and a hammer. Simple and effective. Takes a little time but it´s ok.

Micke · Post by **Micke** » Tue Aug 01, 2006 5:21 am

Here's the way to get the ring and pinion shimmed.
NOT a funny thing to do on a sunny day!

Gearbox rebuild (Lots of pics, hope you don't have a modem)