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These guys can probably help? They were going to be my second choice

I can also ask the classic Ferrari specialist across the road from me here at Silverstone, if you'd like? Always wanted to have an excuse to knock at their door and have a look at the cars, hehe. Let me know.
Oh go on then, if you must :) Classic Alfa sells new magnesium wheels, but not on a 98mm PCD. Our local Ferrari specialist mostly rebuilds the engines, which need rebuilding quite a bit by the looks of how much work they get.
 

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This what you need?
<a href='ac — Postimage.org' target='_blank'><img src='https://i.postimg.cc/Y9zkyhzz/ac.jpg' border='0' alt='ac'/></a>
I have ll these bits too...
<a href='acc (2) — Postimage.org' target='_blank'><img src='https://i.postimg.cc/7LrF8q6s/acc-2.jpg' border='0' alt='acc-2'/></a>
I think 'need' is a very strong word! but yes the first photo is the bit I covet , as that is just like the one I had in my first GTV6, way back in 1989 :0 I'll forgo the old York compressor though, it never really worked very well, and made the engine shake!
 

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Enjoyed reading these posts, mistamum you're doing a great job, I only drive mine and leave all the work to my mechanic
 

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Discussion Starter #85
Oh go on then, if you must :) Classic Alfa sells new magnesium wheels, but not on a 98mm PCD. Our local Ferrari specialist mostly rebuilds the engines, which need rebuilding quite a bit by the looks of how much work they get.
I spoke to the bloke in the classic Ferrari garage. His answer was that they had a go-to guy back in the day that did the whole process for Magnesium wheels but he's not doing them anymore so they avoid it at all costs and end up replacing with modern lookalike aluminium alternatives more often than not. He wouldn't really recommend anyone but if it was really necessary they'd contact a company called Lepsons

I had a look at their website, they have a "limitations" page
I think they do do magnesium wheels, just warn about the quality that can be achieved.

Cheers
 

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Discussion Starter #87
Ever since I had bought the car I knew the synchro rings for 2nd and 3rd gear were gone and would need replacing.
I thought about having it done somewhere but after extensive research on the matter I decided to do it myself.

Once I got the outside of the box clean enough I prepared my working surface to deal with the box, mounted a vice in a more convenient place, split the case, removed the gearbox assembly and started working on it.

Here you can see it on the vice with aluminum jaws but I soon made a wooden template to hold the box and save the machined surfaces of the flange.


As per the manual, one of the critical bits to do before dissasembly is to accurately measure the pinion depth as described in this figure, to make sure it's the same after re-assembly.


I don't have photos of the measuring procedure but it was done at in a CMM which is incredibly accurate.

Then the shafts were removed and the stack dissassembled in order.

Not that it needed confirmation but the synchros were indeed past their best and indeed there was damage to the 1-2, 3-4 sleeves too. In fact it was noticeable that the 5th gear sleeve had already been used as a 1-2 or 3-4 sleeve before.

I chose new synchro rings and sleeves from Sruell Motorsport in the States, they were very sensible priced.

Removing the big circlips from each gear was not that difficult, fortunately, specially with a decent sized set of pliers.
Likewise reassembly of the stack is also quite straightforward with a little bit of assembly goo as required.

Shiny new parts :)


Then the trouble started :)

First hurdle was how to tighten both the pinion shaft and main shaft nuts to the correct torque specification, I didn't have specific tools so I went in with a big spanner while standing on bathroom scales. Not very classy but did the job.

The second issue was how much play the shafts have around the main bearings. I foolishly didn't feel or measure this before and once I felt it aftwards it felt excessive... but nothing I could do about it.

Finally as can be read in the thread below, the pinion depth was out of tolerance once I took it back to the CMM for measurement...
More specifically, maximum tolerance was 0.03mm and the pinion depth had increased 0.08mm, more than double the tolerance.

The culprit, found by means of exclusion, was the (only) spacer washer which seemed like it had been overstressed and had some deep grooves in it.

At that point I had two options
  • Simply accept that the grooves in the spacer meant I was simply returning the pinion depth to its nominal value
  • Remove some material from the spacer as to bring it back to the original measured depth.
I couldn't decide what to do so I resolved to open the diff case and look at the mesh pattern between the ring gear and the pinion.
The pattern really wasn't great at this new pinion depth so I shaved a little bit off the spacer and brought it back to tolerance and a better pattern. We will see how it feels once I finally drive the car.
Oh, please ask me how many times I opened and closed the diff case :)
Initial mesh pattern (power side only, coast was better):

Final mesh pattern

This was how much was removed:


Once I was happy with all that I replaced all of the box bearings except the main bearings and the pinion bearing because those are much more expensive, difficult to replace and require specialist tools. Not to mention they looked okay for the use the car is going to be given.


If may sound like this was quick but it would have taken me more than a month to get to this stage and the gearbox chapter wasn't even closed yet.
 

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Discussion Starter #88
As part of the gearbox refurbishment I also removed the diff internal drive shafts to replace the seals and the bearings which felt a little crunchy.

This guy gave me a little trouble but I was just about able to remove it without medievel methods.


The internal driveshaft bearings are not a press fit, instead they are held in place with a press fit nut, I used a regular off the shelf bearing puller to remove it.


After dissasembly I wanted to treat and paint the exposed parts of the driveshaft, including the dust guard which is made of very thin metal.
Usually I would have used some Deox C but I wasnted to make sure I didn't mess with the machined surfaces which was the perfect opportunity to have a go at removing the rust with electrolysis for the first time.
I made sure I read this incredibly detailed website first, to make sure I didn't poison myself or the environment :)
...and this was my small setup


The results were really good, the machined surfaces were absolutely not touched, first part done on the left.


This are the painted driveshafts


I bought new skf bearings (standard parts) and managed to get a old of NOS seals


The nut is pressed in place hot so it just drops in and the pressure is left on until it cools down below 30 degrees or so.


Finally I closed the box with some good quality sealant, both the diff cover and the central flange.
New bushing too!


Here it is, finished and filled up with gearbox oil which I shook around a bit as I don't know how long it's going to be standing for.


There are a few things still left to do...
  • The breather is a goner, I can't find a direct replacement, not sure what to do.
  • Need to finish the clutch
  • Need to de-rust and paint a few more parts.
 
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