Has anyone had the dreaded transaxle/diff failure?

From a related thread on the TR in another forum area:
http://www.ferrarichat.com/forum/showthread.php?t=112201&page=4

 

Hi,
This is very interesting information.
My car is a late 1994 512tr, and I've been wondering what mods it might have had compared to earlier models, as the air boxes are black, just like the "M".
Is there a list of these service bulletins available on the internet?
From the above bulletins, my car has a later engine, where is the s/n on the gearbox pls?

Thanks for the info

 

See post # 49.

 

The Parts Catalog has drawings indicating where to find the various serial numbers. Without going out and looking at the car I'll try to give enough description where you can find the numbers. I didn't have too much trouble locating them.
GEARBOX: On the back casting, lower left corner looking forward. Numbers found on mine were 124859 and N314. The long number didn't jive with any number breaks in the parts book and the 314 did, so I assume that is my gearbox SN.

ENGINE: Under part of the air cleaner duct on right side. The removeable perforated plate on the clutch housing is near it in the picture.

ASSEMBLY NUMBER: On a frame member between a canister with a bent tubing coming out the top and a rectangular expandable duct.

VIN NUMBER: Found many places in the car but this one is in the engine compartment on right upper frame rail near the above canister (believe it's a fuel filter).

Amo512TR you're lucky; since your car is a 1994 model I believe you have all of the updates that carried over to the 512M, but there may be more that I don't know about. There are many improvements over my 1992 model; some are in the form of Service Bulletins and others simply changes that show up in the parts catalog. If you have a 1994 parts catalog and study it carefully, line by line, every production update will be there by serial number of the various engine/drivetrain components.

I don't know where on the internet you could get the SB's. A top Ferrari technician was kind enough to FAX me copies of those involving the transmission and differential. Other than the ones mentioned in my post #49 are SB30-16, casehardened ring nuts in trans; SB30-17A, ring nuts in trans; SB30-21, springs on synchronizers; SB30-22, reverse idler gear shaft; SB30-20, oil line between gearbox and clutch bell housing.

Several years ago I ran into another one involving an update to the clutch slave cylinder and throwout bearing. I'll have to dig through my records to find the number; a member in the UK posted a copy of it when I was having slave cyl. trouble. I'll look for this old post and copy it in another message.

If someone needs these SB's I'll be glad to FAX or mail them. I don't have a scanner, besides the mass of paper would overload the thread. Others have been helpful in furnishing me with information and the least I can do it help other owners.

Ron

 

Thanks Ron.
I know my engine no, it was the gearbox no which I could not find.
Can u see it from the top if you open up the engine hood?

My motors a Dec94 model, engine no is just under the 37000 mark.

It's great to know that my car has had the 512m mods, I've always wondered it had, but no one could confirm it.

 

No you cant, look under the car at the left rear corner of the gearbox. Cant miss it.

 

Can anyone tell me if the F512M transmission can bolt directly onto a 91 TR or will I have to make other changes to the car?

And if anyone has a line on an F512M transmission, please post or PM me

 

David, why not buy the updated differential from T Rutlands. Then send your box together with the updated differential (and anyother parts like syncros you might think of changing) to Rod Drew in Ca and let him put the thing together and ship it back.

Just a thought.

 

Regarding post #51, does that apply to the Boxer as well? Can the diff be removed/replaced/adjusted through the side covers with the engine in situ?

 

Yes it can.

 

Yes, and while you're at it, use the opportunity to replace the shift shaft seals, at the very least.

 

How can you properly reshim and set the lash for the ring and pinion this way?

From what I understand its critical or you will destroy the R&P quickly if not set up perfectly

 

Waiting to hear from TRutlands - T is on vacation at the moment. Thanks

 

If you're just changing the diff itself due to cracking etc, and re-using the undamaged existing ring/pinion.... setting bearing preload and mesh is very easy, and quite often minimal changes if any are required... the diff and bearings seem more uniformly made than ring/pinions...

to set bearing preload, do this with the ring removed, just bolt the diff up tight with a spacer if necessary.... then, once this is done (with consideration to mesh)... THEN check the mesh and shim BOTH sides of the diff bearing if necessary...

If the pinion height was correct before the diff failure, it will be after... it'll only be diff/bearing manufacturing tolerance that you need to adjust for, to make the ring mesh properly again....

In my experience.. bearings ALWAYS go straight in, straight swap, no messing about... and diff's themselves are usually very good....

 

Maybe I’m missing something here, or just dumb, but if the 2-piece welded carrier cracking is causing all the problems, why not just pull it out and have a good welder do a proper re-welding to prevent it from cracking?
Welding has come a long ways in the past 25 years.
Maybe the ring gear mounting surface would take a little truing up, but it seems to me that this would be a good deal less expensive than replacing the carrier with a newer unit, or waiting to rebuild the gearbox.

 

Because of the potential damage a part like this can cause, and because these cars are so darned expensive, I think of them like aircraft. Now if this were an aircraft part, there is NO WAY the FAA or even the old CAA would have allowed a part like that to be welded. It should have never been welded in the first place. The basic problem is that the very act of welding stresses the area, and its always made cracking easy along a weld. Welding may have come a long way, but you still cant weld on crankshafts, etc. You can on a Chevy, but its totally illegal on a Cessna. Why risk it on a Ferrari?

 

So where do I get a "better non weleded" diff carrier for a boxer and one of those titaniaum twirl shafts. Seems like a worthwhile excercise when I am doing the eo next year.

Going to do some head work cams and an efi, + suspension rebuild. Are there adjustable shocks available for these cars.

Anyway this should lead to a relatively bulletproof hard charging streetable boxer.

Any ideas where to find the tranny upgrade bits?.

 

Head work cams and EFI? Sounds like you caught my disease. I had an extensive dialogue with the guys at Carobu in Costa Mesa about this. It's doable but it's expensive and it smacks the value of the car. Newman had a novel idea: get a wrecked TR 4v engine and work it into the Boxer.

 

Frank Capo, Modena Engineering here in Melbourne... he's made 100's and ships them all over the world.

I've used his 360 ones extensively (very similar to BB)... they're heavy but tough

I think Rob Schmer????horn "rexcr"? is an agent for you guys over there...

 

Hi,
Any adress,phone n° or internet site?
Idea about the cost of a titanium shaft?
Speedman

 

rexcr is a site sponsor... deltaV or something...

edit...

http://www.deltavee.net/

 

Also a site sponsor:
http://www.ferrarichat.com/forum/sponsors.php

 

I contacted them and got a quote of $11,500 for both trans and diff.

 

trutlands has 512TR gearboxes ready to go for $14500.00, ouch.

 

Is that deltavee?