Testarossa input shaft upgrade available.

Hi guys.

Recently a mate in Oz had a failure of his input shaft in his 1990 Testarossa and after looking around and talking to a bunch of people, these appear to have some serious issues and some very dramatic and expensive failure stories attached.

Following in Mr. Newman's footsteps re the replacement diffs, I decided that it was overdue to source a replacement component for this input (quill) shaft made out of better / faster / stronger stuff that would let us all sleep at nights knowing that we didn't have to stress about breaking an input shaft next time we take our cars out for a Sunday drive.

And they do this without any warning! The split shaft image below happened as the owner was backing out of his garage one morning in a 512BB.

I found out that these shafts are nearly the same in 365 / 512BB / 512BBi / Testarossa / 512TR and in fact didn't change until the last few 512TR's and the 512M where the shaft diameter was increased to give more strength.

The updates 512M shafts are made for Ferrari by ZF and they appear to not make them any more and the three that I located in the World were all circa $4500 USD?

Most 512 / TR owners will be aware of Modena Engineering in Australia who have been manufacturing racing gearboxes and performance driveline components for European exotic and racing cars for many years. I decided to take a drive and speak to them, and learnt that back in 1996 they assisted a team in the UK by manufacturing a performance quill shaft and a stronger diff centre for a 512M race car. From all indications, this car is still racing in Europe and even after all these years of racing abuse, is still using the Modena diff and quill shafts which have performaed faultlessly over goodness knows how many racing kilometers. 16 years of hell and zero failures certainly impressed me.

As a result of my visit, Modena pulled out the old drawings and has created a short run batch of shafts for me. Two have already gone to new homes in Australia for fittment into a 365 and a Testa, and one will be going into my car at the next major in a few months, but I have three still available and will probably be able to do another batch in the new year if required.

Here's some pictures of original shafts. Most shafts break just near the head where the internally splined section is attached.

Others shatter along the length of the shaft. This is caused by excessive bending and twisting as load comes on and off. These shafts actually twist slightly as load gets applied, but many also bend. When they do this you can see a shiny mark on them where they actually come into contact with the gearbox casing. If you see this shiny mark, then you know that your shaft has been flexing a lot rather than just twisting as it was designed to do.

If they shatter, just imagine what happens when those bits fly up into the box and get meshed in your gearset. Kiss goodbye to Christmas presents for a while if that happens.
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Here's some other images.

You can see where the two piece section is fused to the original shaft. About 1/2" below this join is where most shafts seem to fail, or right in the middle from whacking against the casing.
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Here's some pictures of the new shafts that I have had manufactured. They are made in a single piece which spreads the twisting load along the entire shaft length. As a single length there is no secondary component to snap off, and as earlier indicated, 16 years of racing in the 512M and no gearbox breakages that I can unearth.

This shaft is the same diameter as the late 512TR and all 512M shafts that ZF produced, but the major change is that it is constructed as a single piece component.
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More detailed images of the new shafts:
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Difficult to say what causes that twisting Brian. Maybe the ZF material used to manufacture the later shafts is not as flexible as the earlier 16mm shafts.

Yes, we can consider that shaft to be the 'fuseable link' in the system but it it doesn't do it's job very well if it lets go and allows shards of hardened steel to mesh with the rest of the gearbox internals.

I guess that Modena agreed with you in that the 512M shaft was potentially problematic and hence they had to re-design that race car shaft to allow more torsional flexibility without fear of rupture by utilizing better materials and a single piece design.

 

Like Paul Newman and Dave Helms, I'm a keen owner trying to assist others with a problem so please don't discuss this product comercially in the forum but contact me directly for pricing and availability.

[email protected] will find me.

Expect a pleasant suprise around 1/3 of the quoted Ferrari pricing for the ZF component.

 

Here is what happens when our cars are fitted with the 'updated' factory 512M component.

http://www.ferrarichat.com/forum/newreply.php?do=newreply&noquote=1&p=140129267

I sent those images to my manufacturing engineer and then followed up with a call. The engineer wasn't surprised at all. Apparently they did a lot of testing on the M series racecar in the UK and found that the upgraded transmission components were much more savage on the system due to the larger diameter and this extra thickness allows only a percentage of the twist found in the earlier 16mm shafts.

Therein lied the problem. The early shafts shattered and threw bits into the gearbox or bent so badly (like a banana) instead of twisting, that they rubbed on the side casing of the gearbox. This is why he designed the new shaft. He needed to ensure that it had plenty of tortional twisting ability, but didn't actually bend and that the springing in the shaft took the load off the mainshaft.

He didn't say if they had needed to replace the race car mainshaft or not, but one could possibly suspect that on an inspection at some point a keen eyed mechanic spotted the twisted mainshaft splines and hence they discovered that the upgraded M spec quill shaft was the issue. This resulted in the redesign and remanufacture of this component.

16 years of racing with no further failure supplied the proof that he got it right. Naturally he's looking after his intellectual property and he won't tell me 'exactly' what material is used, but he made reference to other shafts that he manufactures for the V8 supercar race series here in Australia. These are the local Ford / Holden cars running 6 litre V8's around tracks like Bathurst at 300 km/ph. They also were snapping shafts and since he remanufactured them, there have been zero failures.

He tells me that when those guys dump the clutch off the line that their shafts can twist more that 270 degrees and then return to normal without bending every time. This is the material that he's used in our Testa shafts. He's adamant that we don't need a 'fuseable link' but what we do need is a product that allows serious tortional twist without distortion and the fear of bending or snapping. Hence that's what he has made for me.

We know that the early model quill shafts twist substantially. We also know that they can bend like a banana as evidenced by the polished central section where it rubs on the gearbox casing. It appears that ZF (who manufactured the components) looked at this and their solution was to simply enlarge shaft diameter. Given the reports of damage that blokes like Brian Crall (and now Grady) have seen over the years it appears that ZF got it wrong. Increasing the shaft size only limited the tortional ability of the shaft and forced the load point further upstream, for the most part twisting the main shaft splines, or worse!

It appears from these two specific areas of knowledge that what is needed is a shaft manufactured from the best modern material possible that allows the shaft to tortionally distort to a massive degree, thereby 'soaking' up the shock loads, without the fear of bending or snapping. Then no additional or excessive loads can be passed on to the expensive mainshaft and also there will be no damage to the gearbox casing through 'banana' distortion. These are the characteristic of the shafts that I have available. There will soon be four cars fitted with my shafts and I'm sure those owners will post their comments here.

 

Seems that's the case Jeff.

Those V8 Supercars are our version of your Nascars except that we run on 'normal' curcuits instead of banked ovals. So every few seconds they are under extreme loads as the car downshifts and applies power to exit another corner.

Modern metal alloys must be truly amazing compared to the metalurgy technology that was available when the 365 / 512 / Testa series was manufactured 25 years ago.

 

Try this:

http://www.ferrarichat.com/forum/showthread.php?p=140129267#post140129267

 

No worries, my bit to help out with a known issue. Two shafts in the States now so those owners will be along with their feedback shortly.

 

Nice to see you back on the road. Glad everything went well.

 

Time to rekindle this thread.

With Mel in Holland going through a gearbox rebuild, and mine with an as yet unknown internal failure, there has been renewed interest in sourcing gearbox repair parts from the four corners of the World to keep our great cars on the road.

I have had some interest from the USA for the replacement quill shafts that I can supply. If I can get four more advanced orders I will arange another run in the new year.

As long as the supplier can do them for the same price they will be $1500 AUD plus freight. I sent the last ones to the US by airmail with insurance for just under $100.

Either reply here or drop me a PM if you are interested.

You certainly don't want to risk a quill shaft failure, especially if you have recently gone to the trouble of fitting one of Paul's diffs.

The previous shafts were installed into 365's, 512's, Testarossa's and a 512TR and all of the recipients were really pleased with the quality of the component. They are another step in the upgrade path for our cars.

 

Not yet Jim, the TR boys must be still counting their 'post Christmas' pennies to see what goes on the 2012 shopping list.