Dismantled 330GTC Transaxle

what breaking lube you planning to use with the new parts?

 

In my experience the friction reducing additives in modern GL5 oils really inhibit the operation of the Porsche style syncros especially when brand new. Syncros are just a brake and some oils are the equivalent of greasing your brakes. For many years with fresh syncros I have been using very cheap GL4 oil. Good quality GL5 may work fine after a break in.

GL5 oil with its high degree of friction reducing additives did not exist when that transaxle was built.

 

And do not buy into this GL4/5 stupidity. It is still GL5 and the specifications in some ways are at odds with each other.

 

I'll see you and raise with one, although these two are from Daytonas.
Both done & thoroughly documented, including countless photos, several years ago with many happy miles since.
One had a very interesting manufacturing defect its manufacturer (ZF), Ferrari and both owners had just ignored since day one.

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I've done alot of "do it yourself" tasks on the ferrari - never a transaxle! Impressive!

 

While properly rebuilding/restoring/setting a GTC / Daytona type transaxle can be time consuming (& costly) endeavor, it is relatively easy and simple compared to rebuilding a Cord 812 transaxle and all its ancillary electrical controls & vacuum operating systems I just got done with.
3 new gears, a couple of shafts, all the bushings, synchros, etc had to be custom machined/made and fitted for it and all that was the easy part of the job, but made more complicated by someone else’s previously performed hack work.

 

Thats pretty much the name of the game these days, even on much newer cars. It has become the norm for me to give as good an estimate as possible then a follow up estimate when I get it apart and find the destruction caused by prior bad repair work.

I have a 250 here now. Nice looking car. Spent most of its life in Belgium. Stopped running because of rust in fuel system. The entire fuel system is a horror show from butchery that looks pretty recent in some nature of restoration that took place prior to auction in Europe. It has me afraid to open any more cans.

I have a TR here that will end up possibly doubling from initial estimate due to what was done in the past.

Both are new customers so I was unable to assist is selecting the recent purchase.

 

Hmmm, I have a Cord 812, and have been through all of it. Perhaps I should step up to a GTC, or Daytona now?

 

I have one of those "new customer" (another non-Ferrari, nearly 70 y.o.) jobs I (and now the owner) wish I would've been consulted prior to acquisition, which would've prevented a nightmare we're both now committed to.
Unfortunately, not only the previously performed hack work is making the job much more difficult and expensive, but the owner having shifted the goal posts more than once is not helping either (initially job was to make the car reliably running and operable before shipping it to Europe where the owner lives) and preserve most of its unrestored, original* exterior & interior finishes, but the slippery slope to full restoration has taken over and multiplied the initial, rough estimate.

This is why I don't actively/often accept or solicit "new customers". Most of mine are long established & understand how I do things and are able/willing to accept consequences of doing things "my way", i.e. correctly (or at least to best of my abilities).

* One of the many features the current owner was enamored with included sellers claim of the car having nicely preserved original paint, due to being stored inside a SoCal garage since 1964, but my first glance of it revealed it wasn't a factory paint but rather an E. Scheib type (close color matched) job shot over the factory paint some time in the early years (prior to 1964 ?) of the cars life and the seller either didn't know or took extra efforts to give it an appearance of buffed & polished "nice patina" BS.

 

I was thought by one of the best and strictly warned about the use of synthetic gear oils. The limited slip clutches rely on a certain amount of friction to lock up. Synthetics are too slippery and cause the clutch discs overheat and fail.
I’ve attached a photo to illustrate.
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The

They are the same clutches used for many more years, up to at least the 360. I have been using exclusively synthetic oil in all cars after the Porsche style syncro cars and have not once seen that happen.

Any slipperyness is more a function of the GL5 formulation than if its synthetic or not. It is exactly why the GL5 spec exists.

 

We have had very different experiences

 

I was shop foreman in the largest dealer service department in the world and we never saw a single case of that.

And the very same clutches have been used in Porsches for decades. Between the 2 brands 10s of thousands of cars are running synthetic gear oil with those clutches.

 

I started with Luigi Chinetti Motors, the Importer at the time, in 1975. The experience started a long term apprenticeship under the Shop foreman and former Ferrari factory mechanic from the Sala Prova in Maranello. Coincidentally he is the subject of a recent article in Cavallino magazine.
We did dozens of transaxles together and he was generally considered the best at his craft.
What I haven’t seen on this bulletin board is anyone with the special tools and shim assortment to do a correct rebuild.
I respect your opinion Brian and trust you afford me the same courtesy.

 

Not when you say something so clearly wrong.

The combined experience of so many thousands of cars in service means it is not a matter of opinion.

 

With all due respect Mr. Castelhano, but how exactly was it determined your illustrated problem was caused (only) by use of synthetic gear oil, without any other potential contributor, like incorrect (previous) assembly, insufficient amount of lubricant, other contaminants in the lubricant, etc ?
Who refilled the given differential with synthetic gear oil and/or how was it determined to be “synthetic” ?
Just curious and trying to learn.

 

I have always used laboratories that perform oil analysis primarily for the aircraft industry which is mandatory in that field. That’s one contributor, the reports tell a story, the second method is to measure the point at which the limited slip unit actually slips. With new discs installed with the correct preload the clutches would not lock correctly and would slip with very little pressure.
Since the subject of this thread is 330 transaxles my comments pertain entirely to the transaxles found in 275, 330, 365, and Daytonas. I have no direct knowledge of 360 Modena etc…
Lesson’s learned in the 1970s and 80s have served me well.

 

in my eyes there has nothing changed in the structure of the diff. all the same, only the torson diff works different, so without clutches

 

I have two round discs which mount to the axle flanges of the transaxle. Each has a 1/2 inch square hole in the center. A breaker bar is inserted in one and a torque wrench in the other. With the breaker bar held fast the torque wrench is pressed until it breaks loose. The torque is recorded .
We discovered many years ago that the torque readings for synthetic oil were lower, thereby out of spec, than regular EP gear oil for this type of gearbox.
To me it makes sense.

 

While it doesn’t really address my specific question(s), thank you for the reply Sir..
Having myself rebuilt/restored various differential assemblies, including those in transaxles, with (& without) friction disc type limited slip units in various vintage cars up to early 1970’s, including Ferraris, I’m somewhat familiar with the characteristics & procedures for setting preloads for said limited slip units.
I too have sent oils & lubricants for laboratory analysis and often found results quite interesting, helpful and useful, but don’t have enough experience yet to interpret or solely rely on them to pinpoint exact causes for various component failures.