[ECSofVirginia]

We had an '07 599GTB come in due to a gear oil leak and found a oil cooler quick disconnect line loose and leaking. Digging deeper found evidence of a literal Rat's nest in the back of the car as well as signs of someone being in there previously.

After fixing the cooler line connection and cleaning out the nest, a test drive discovered that the 5th gear synchro had failed and was "crunching" during shifts over 4000rpm.

The next few posts will follow the process of replacing the 5th gear and synchro assembly, as well as checking and cleaning the other gear assemblies.

Enjoy the pics of the process of disassembly. Next will be scrutinizing the individual parts of the synchro assembly and preparing to reassemble.

[tazandjan]

Josh- That is a rare one. About the only way I could think of to hurt a 599 transaxle would be to run it out of oil, which it sounds like they did.

Look forward to watching you tackle the rebuild.

[ECSofVirginia]

Terry, I was quite surprised when I heard the gear crunch while driving. As you mentioned, I am approaching this under the impression that oil starvation was a contributing factor. I was concerned about the possibility of there being a TCU software issue as the early F430 experienced. We contacted a dealership to verify if any TSB's existed and were told that nothing exists related to this issue.

I'll make sure the gear sets are shimmed correctly, clean out the debris, look for other worn parts and then get ti all back together.

Once the transaxle is back in the car we'll bleed the F1 actuator, run through the actuator self learn procedure to make sure it's calibrated correctly, bleed the clutch line and put it back on the road.

There was also enough fine metal particle in the fluid to indicate that removing the trans oil cooler and cleaning out thoroughly will be necessary. No "chunks" or broken teeth have been found at this point, I consider us lucky.

[Killer58]

The fine metal particles are interesting and concerning. Not necessarily related to oil starvation.

[tazandjan]

Josh- What did the transaxle filter contain? Just fine particles?

[Granucci]

Additionally, can you comment on what type of fluid the owner knew of put in or from prev. worksheets.

[ECSofVirginia]

The metal we found is plain steel dust. Inspection of the gear sets indicate that it's from the synchro assembly teeth being forced into each other as opposed to gear teeth grinding off. The wear pattern on all teeth is normal.

The filter had a couple small metal chips and particles in it. Enough to confirm that something had failed but not enough to indicated a catastrophic failure. It is somewhat normal to see small debris in the filter. We did also get some particle flushed out of the oil cooler as well.

The car came with no service records, so we have no idea if the fluid was original or replaced. The current owner had tried to obtain them but nothing showed up. It's quite possible someone was aware trouble was brewing and tried to move on.

I'll be using the Redline gear oil as usual. I took a couple more pictures, you can see the 5th gear/synchro assembly dissected. The last picture illustrates the failed brass "clutch" inside the synchro assembly. You can see how the brass has been burned and wiped right off.

[StefVan]

I didn't know that rats have such a sharp teeth

Seriously, this is a very interesting thread. Thanks for sharing the internals of the 599 gearbox, something which is very rare to see.

What kind of abuse or mechanical failure can cause such a burned brass in the synchro, especially the 5th gear? Can the root cause be a failing F1?

[ECSofVirginia]

Me either Stef! Fortunately it doesn't look as though they chewed anything in the car, they just used it as storage for their findings.

I agree that it is not often we get to see these taken apart and would be good fun to share with everyone.

As I'm sure you know, the basic causes of a failure like this are inadequate clutch release during the shift causing torque load on the synchro, inadequate lubrication due to a faulty pump or wrong gear oil and incorrect gear oil level (too high or low).

The clutch engagement and shifts all felt good while driving, the sound of the bad synchro was our only indication of trouble. It is possible there was an issue with air being in the F1 system and causing faulty actuation, it wasn't present when I drove or checked the hydraulic system though.

The fluid in the F1 system was factory fluid, not Pentosin which indicates it not as likely that someone had opened it up and re-filled.

As mentioned before, I was concerned about an error in the TCU software. The sensors in the F1 system gather enough information that it is unlikely that the transaxle would abuse it's self at this rate. If there was a fundamental software issue, nothing would override that however. After contacting the dealer, no mention was made of a known problem so we're currently considering that to not be the case.

Incorrect gear oil selection is possible, we have no way of knowing for certain if the oil was original or replaced with something inadequate though. We do know that a measurable leak was present though.

The 5th gear assembly is on the upper most Lay Shaft and positioned towards the front of the trans axle, furthest from the transaxle oil pump and filter.

From what I'm seeing, it is fairly evident that a lack of oiling is the cause of our trouble. A lack of lubrication would explain why the brass "clutch" was able to make enough contact with the outer ring to get hot and burn off soft material.

None of the other synchro assemblies showed signs of suffering similar trouble. There are no suspicious gear teeth wear patterns either.

Once everything is together and the car is functioning again, I'll spend time with the computer checking data points to do my best and make sure the robotics are functioning correctly.