Syncro fix for GT4 #10314

The gearbox has been reassembled and is ready to be re-attached to the engine. And as I look back (now), it occurs to me that the name of this thread is misleading.

So I will refer this thread back to the original thread on my car here:

And to keep the continuity intact, I will make reference to this thread for anyone curious enough to want to read about the synchro saga, in that thread.

But first a cautionary tale...

The problem with the gearbox was not the synchromesh gears as I had first assumed. Instead, the problem was several severely worn gears. It has now been reconditioned (vs. being “rebuilt&#8221 by Eric Sanders. Eric (ferrarifxr here on FChat) is the shop foreman at Auto Gallery in Southern California, and also owns a beautiful black GT4, which can often be seen at VCR on Sunday mornings, and also occasionally goes on some of the weekend runs. So he’s not only a very qualified Ferrari mechanic, he is also an enthusiast who owns and drives one of these great cars regularly.

When I first took the transmission to Eric with the two new synchro’s to install, he called me back a few days later and said, “I don’t want to re-assemble this gearbox with just replacing the synchro’s. The gears are severely worn and really need to be replaced too. I could simply put it back together, but it would do little good, and the gearbox will eventually fail, causing a much greater problem for you down the road.”

Needless to say, I was dumbfounded. I had a budget of about two-thousand dollars to complete the repair. And that was also to include a few new parts, like ring-nuts, a new boot for the shift-shaft and at least one new differential seal, because I noticed that one was leaking bad enough that the differential flange was full of fluid when I separated it from the half-shaft.

Now Eric was telling me that I needed to either; 1) buy a new set of gears (rebuild), or 2) acquire a spare transmission with good gears and perform a complete swap (re-condition). And I obviously went for option #2. New gears would have put me upside-down for the entire cost of the car, and the benefits of doing so (unless I am going to race the car – which I’m not!) do not outweigh the extra cost.

Eric found a good gearbox from Bill at GT Car Parts in Arizona. The cost for the gearbox was $1500 (exchange), plus shipping. Bill promised that everything inside the box was in very good condition, including even the synchros. But at this point of course, my small budget had just been severely blown anyway. But what could I do?

Eric showed me the gears, and I have posted a number of the pictures below. He also drilled the relief for the blind-hole that one of the shift-shafts goes into. (see picture) This should make it easier to shift (into 2nd gear IIRC) when the gearbox (and fluid) is cold.

Gears are made of soft metal on the inside, and then coated with a harder metal on the outside to make them stronger and wear longer. This is the same way camshafts are made, as I know from a camshaft I have that was ground-down to the soft metal, to gain extra clearance, by Alfa Romeo of BH, when the valves were re-seated too far into the head, after a rebuild that became necessary when the 1st owner decided that he didn’t like the protective oil-pan grate rattling when he bottomed-out the car and had it removed. That smart move resulted in punching a hole in the bottom of the oil pan the next time he bottomed out, and the rest of that story was, well… Very expensive! And grinding into the soft metal caused me problems later on too. But that’s another story.

So now with the new gears replaced, good synchros, and everything "in-spec" and "as new", it is all ready to be reassembled. But first Eric asked me to come by, so that he could show me what he did, and why he needed to do what he did.

Eric showed me the worn gears. And you can see the soft metal showing through the hard metal on many of the gears in the pictures below, and some of the gears are also pitted.

Eric had me grab the long main shaft that comes out of the box and had me turn it. You can see my hand turning the shaft in one of the pictures below. The gearbox was set in neutral, and as I turned the shaft it’s important to note here that, EVERY GEAR IN THE BOX TURNS! Everything moves when you’re in neutral. Even the differential turns. Although, it can be stopped with simple hand pressure, or by holding the differential flanges that connect to the half-axles, much like applying the parking-brake.

But, I also noticed something that had not been the same when I first separated the gearbox from the engine. There was almost no play! Everything turned very smoothly. When I pulled it apart, there was noticeable play when turning the shaft back-and-forth. And now, all of that is gone. It’s all tight, like it should be. And hopefully, my gearbox will be a LOT quieter as a result.

Eric then grabbed the flanges on the differential and held them still. At that point, the back pressure on the main shaft increased, and as I continued to turn the shaft, he said, “This is how much pressure there is when you are in neutral and standing still”. He then let loose of the flanges, and turning the shaft became much easier, as the flanges began to move with the momentum of the gears in the box. Eric then began to turn the flanges in the direction they wanted to go (I presume it was forward) and the turning of the shaft became even easier. “This is like rolling forward in neutral”, he said.

Then he added, “All of this pressure (and even more when there is fluid) is going on when you are in neutral. And when it’s cold, and the fluid has not coated everything properly, and you rev your engine up really high, like so many guys like to do to show-off the “sound” of their cars; All of this movement is going on in the gearbox and it’s wearing on the gears, like metal-on-metal”.

And this is a very VERY quick way to ruin a gearbox! So don’t do it.

Apparently the 1st owner of my car liked to do that. Since this exact same problem with the gearbox was reported by the 2nd owner of the car, who bought it back in the late 1970’s. And over the years of course, it’s simply gotten progressively worse.

If your engine AND gearbox are completely warmed-up, then maybe you can rev-away. Although after what I’ve been shown, I wouldn’t recommend it. But that choice is yours to make. It’s your car.

But be careful, because now you can’t say you were never warned.
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Just found this picture from earlier in the thread. It's the 7th picture in the series of 9 pictures on the previous page.

This gear actually shows the wear better than any of the ones I took at Auto Gallery.

You can see how the metal is worn though on the teeth below my fingers. And several of the gears looked this bad.
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LOL!!!

Well, I'm going to do some extra stuff first. So it'll be a few more months. But I am really itching to get it done quickly.

First off, the car is going back to the original Blue-Dino-Met.

While that is happening, I am going to:

1) Detail the engine.

2) Install XDI ignition

3) New cam pully's and belts from Nick's, so I don't have to change belts every 15K miles.

4) Installing the adjustable shocks

5) Upgrading the brake disc's to the drilled gold ones.

6) Install 355 bushings on the A-arms.

7) Upgrade the wheels. I haven't decided which wheels yet, but I'm leaning towards the HRE 288 GTO style rims. I wish now that I'd bought Robert Garvins's, when he had them for sale for $1000.

8) Obtain and install a new style rear bumper

9) Install the interior A/C box

10) Replace the front grill. Mine was missing when I bought the car

11) And THEN I'll finally be able to install Birdman's fuse blocks that have been sitting here on my desk for the last YEAR!!!

After the car is back from the bodyshop, I'm going to have Eric install the engine. I'm not going to risk messing up the paint again. Especially with a new paint job!

And I'm still considering some carbon-fibre upgrades. But I think that will wait until later...

So will I be upside down in the car? Most certainly. But not by much. I got the car at a VERY FAIR price. So it's all good. The car will be better than new when I'm done. And it'll look like it too!

 

There is a premanent stain on my shirt from drool as well. And I wish I had the time, inclination and money to do that kind of job too.

It would make no economic sense to do that to a GT4, of course. And the route I'm taking will actuall produce a car that is a little more mechanically updated from an original.

But still, it sure would be fun!

 

Reccommend getting them from Bill at GT Parts in Arizona.

T.Rutlands has the ZF ones, but if you look back in this thread, they are VERY expensive. And they don't take returns after 30 days.

I found that out, because I can only return mine for a "credit", towards purchasing something else.

GT Car Parts however, will accept the return. And the cost (IIRC) was about 2/3's the cost of T. Rutlands.

 

The pictures are posted a few pages back in this thread.

The 2nd gear synchro is burnt on the back. 3rd didn't look too bad. But the gearbox was re-assembled with all of the gears (incl. synchros) from the box from GT Car Parts, because everything was well within factory specs.

 

May my misery lead to your pleasure.

And if so; It's a pleasure (well, sort of anyway) to share some of my misery!

You''re quite welcome!

 

OMG... That was 1yr + 4-days ago..

And that's why you're a "Consultant", and at the time I was probably still "Karting"....
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Just as a side note though...

Mr Fallow, the PPO had almost $50,000 into this car. And then had it for sale in San Francisco (about 3 years ago) for $18,000. A friend eventually bought the car and kept it for a year before he sold it to me for even less.

So by the time it's done, with proper paint, etc... It will almost be that restoration you mentioned. I'm guessing there will be just about $70,000 into this car by the time it's all done. I will have $30,000+ into it. And most of that in paint and body work.

So how bad can it be?

One year down. Nine to go!

 

This is all Tillman's fault!

9-years and counting.....
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Thank you Difaz. Mine was worn gears. All good-to-go now. 😉

 

Don't say a word.... not a single word!!!