Bugatti EB110 Transmission Oil

[Scott_Tucker]

Sample is from a Bugatti EB110. It was reported that there was damage to the center differential. The story as to why they thought it was is really vague. I believe this to be Swepco oil. Based on this report, I think whatever problem there is supposed to be is elsewhere.

UOA image removed per request.

 

[285south]

Thank you for posting this!!!!

 

[Trav]

This seems to be a problem with UOA's. The unit could literally be in bits and pieces and come back with a good UOA.
I saw one 1.8 BMW engine with a rod through the block that had consistently low wear UOA's including the one after the catastrophic failure.
The engine had mild sludge build up and varnish, which was also not detected by the UOA.

 

[d00df00d]

I really, really wish more people understood that about basic $20 UOAs. It takes a LOT more money to get good information about wear and severe mechanical issues from a UOA...

 

[Scott_Tucker]

Do you not think that if the differential failed there would be metal in the oil? Everything I have heard about this problem has been hearsay and no one has properly diagnosed it yet. I have not experienced any problems but the front axles are removed. I am just trying to get an idea of what is going on. If there were massive amounts of metal in the gear oil I would have definitely suspected something. In order to get to the diff I have to split the crankcase since the gear box and the crankcase are one casting. It would be a lot of work to get it out and then find out there is nothing wrong with it.

 

[d00df00d]

Originally Posted By: Scott_Tucker
Do you not think that if the differential failed there would be metal in the oil?

Of course. The question is what size the particles would be. Blackstone uses ICP spectroscopy, which only catches the smallest sizes. If the failure is mainly hurling out big chunks, a basic Blackstone UOA would miss those completely.

 

[Scott_Tucker]

This is what happened to the car from the rumors I have heard. First of all, this is a quad turbo V12 with 600 HP so it's pretty powerful. It needed to be put on a dyno and it is 4wd. The guy only had access to a 2wd dyno. Instead of removing the front axles he decided to put line-lock valves on the front brakes only. So the front wheels would prevent the front diff from turning. This thing has a viscous center differential. Supposedly he ran it like this and it seized the center diff because it friction welded itself together. He thought the center diff was open. I've been told those viscous diffs are sealed and have their own fluid, but I did not hear that from a reliable source. I'm wondering if that center diff could have seized without shedding any metal into the gear oil.

 

[901Memphis]

That's an awful thing to do to that car!

 

[SteveSRT8]

^^^ times a dozen!

This thread proves that some folks have more money than sense!

 

[Trav]

Originally Posted By: Scott_Tucker
This is what happened to the car from the rumors I have heard. First of all, this is a quad turbo V12 with 600 HP so it's pretty powerful. It needed to be put on a dyno and it is 4wd. The guy only had access to a 2wd dyno. Instead of removing the front axles he decided to put line-lock valves on the front brakes only. So the front wheels would prevent the front diff from turning. This thing has a viscous center differential. Supposedly he ran it like this and it seized the center diff because it friction welded itself together. He thought the center diff was open. I've been told those viscous diffs are sealed and have their own fluid, but I did not hear that from a reliable source. I'm wondering if that center diff could have seized without shedding any metal into the gear oil.


The fluid in the center diff possibly has nothing to do with the transmission, it could use a silicone based fluid.

http://www.autozine.org/technical_school/traction/tech_traction_4wd_2.htm

 

[artificialist]

If you locked the front wheels, you would make the differential turn at 1/2 the speed of the car, which is far more than it can take.

I have heard of some people removing 2 CV axles to use an AWD car on a 2WD dyno, but that still doesn't sound right.

 

[Scott_Tucker]

I currently have the front axles removed and it does just fine in 2wd mode. The guy who worked on it before me was an idiot and did a lot of damage to the car.

 

[Scott_Tucker]

Here is the updated report

[img:left]http://imgur.com/ac51eSW[/img]

 

[901Memphis]

Nothing wild in that report. This is the report from the damaged parts?

 

[Rand]

Probably giant chunks or hunks.
not alot of fine wear particles when you blow it up in a couple mins.

 

[Scott_Tucker]

Originally Posted By: Rand
Probably giant chunks or hunks.
not alot of fine wear particles when you blow it up in a couple mins.


If there were huge chunks you would think I would hear some noise. The trans, front and center differential, and a bunch of other gears are all within the same case.

 

[d00df00d]

"Giant" compared to what ICP spectroscopy catches is still really small. I'd imagine it's at least possible to have particles too big for ICP but still small enough not to cause audible issues.