Differentials available for Testarossa / 512

A Forza components diff from the UK was recently fitted into a TR here in Melbourne. The diff was fitted with engine in the car and it all went as smooth as silk.

Another member here did his own at home in Sydney with engine in the car. It's not a problem.

 

To do it in the car saves the labour costs for engine removal and replacing. It really does depend on the time frame for doing belts etc. If belts are close do it then. I had just done my belts and detailled the engine bay when my quill shaft snapped and while I had the bell housing off decided to look at the left side of the carrier and did not like what I saw , deciding to replace the diff in the car. The only thing I would say from a novice point of view is that trying to be really careful and not scratch any components in a limited space is at times frustrating. Although in theory you only need to lift the diff in once, for various reasons, I did it a number of times and it is demanding to get it positioned without marking anything. Taking the LH headers off can be a challenge if any studs are frozen or you you do not have all the right tools. As you can see in the photos the engine assy can be jacked to clear the crossmember, which normally sits in line with the diff centeline.
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Amazing !!!! I would get crazy doing it that way, but you showed us it works ...

Good for you !

 

Okay, but how you measure the preload for differenzial?
regards

 

Andre, can you explain your simple question a little more for the readers here ? I think you do not believe in installation this way, only with the gb on a bench !

I think this needs a bit more info for them ...
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If the diff is changed in the car the preload etc is setup the same as if on a bench. If the whole box is apart on the bench then you could setup with the F tool on the end of the Input shaft and do your measures that way. Most diff changes still have the box intact and therefore the standard F tool as per the manual will not work. There are some torque type wrenches avail that measure torque while rotating the diff via the centre bolt that goes into the diff centre. I did not have that available so did some maths and worked a spring balance on a flange bolt. Backlash was measured in the usual way with a magnetic dial guage. After getting it where I thought it should be then pasted the crown and pinion- all was good. I then had my very helpful ferrari mechanic come and have a look at my setup and confirmed that all everything was in spec.
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The F tool ............. do you mean this (self made) one ?
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Thats the one, so you can see it is imposible to do that setup with the box in the car...

 

O.K. .... but why not do the exchange wit an Engine-out ?

How do you convert the measurement values to digital ?

The easier way looks simple, but I hope in the end you don't regret it ....

 

Mel, as I have said previously I had just done a major and restored the engine bay to concourse level. When I did this a few years ago the diff failure rate was not too much of an issue, so I did not even investigate at that time. When my quill shaft broke it was then easy with the bell housing off to check the diff. I saved about 10hrs of my labour by not taking the whole engine out and risking any damage to my engine bay. I can not remember the figures for my measures but you can work it out. I also had my Ferrari guy check the pasting and preload and in his words he could not have done any better.

 

Most important is that people / owners can read here all about the diff problem: it does exist !!

And they find the leads here to the two main diff sellers: in CA and UK !

 

I like seeing the repair DIY w the backlash. I have done timing belts, but this is new to me.

If one of the sellers would take the time to post the process...they definitely are getting my business.

This would include the part numbers for the new bolts and bearings in one simple location/post....and also the backlash specs.

Has anyone found a useful sight to explain the preload/backlash?

 

Not that easy Tim; I also think that not all diff bearings can be bought just like that ...

But indeed ask Steve or Phil about it

 

need a diff for my 512 tr, has anyone tried one of these diffs......are they available to buy now....

 

just had engine removed on my 1992 512TR for cambelt service, and found a lot of play in the drive shaft flange, on removing plate and flange thinking it would need a new bearing, found the diff carrier fractured. so all in all a lucky albeit costly find, it could have been a catastrophic failure , i had no noises of any kind driving the car so would have had no warning of failure. will now replace with the later modified carrier. will post picture of old diff when i can....

 

Yes, do contact Phil in U.K.

It's the only diff that is complete with all internal parts new. And life-time waranty.

 

How many miles on that diff?

 

car had done 33k very easy miles, no racing or misuse so just one of those things, incidently have looked at all the diffs that are available. the big problem is that most approved Ferrari specialists in the UK are not too keen to fit parts manufactured by people other than ferrari, they will not give guarantees on the work done if parts are supplied by customer.......

 

They want to replace the part with another weak Ferrari part? NO WAY for me!! Instead I'd use Phil or Newman units and I think they are cheaper. I had one of them in my hand once at Paul's shop and compared it with the original. This is a MUST when I'll get a TR. Sorry but I believe much more in a fully machined part instead of a cast and welded one.

 

Hey Bazzis, I just finished putting in one of Phil's units. If you need any instructions, you'll find a huge amount of help here. This issue has been well documented and the repair process, although complicated, is very well known by several people on this forum.

I'd suggest you start a new thread regarding your experience. It's much better than reviving a 3 year old thread.

 

My F dealer sees this UK diff + its certificate as a big PLUS when ever I want to trade in the 512TR at his shop he said !

(He is fully aware of the OEM s..t diffs ...)

 

Plenty of Phil's diffs have been fitted. Four at least here in Australia and none of the Ferrari mechanics had any issues fitting them.