Porous Casing

[lorazepam]

Has anyone heard of this? I had weeping at what looked to be the clutch push rod seal, and had the bike back at the dealer for warranty replacement. The head mechanic, Aaron said it was not the seal leaking, but the fluid was coming from the case next to where the bolt that holds the pushrod arm is located. they took a lot of pictures, and are going to send them to Italy, and hopefully get a new rear case for my transmission.
I have never heard of this before, but Aaron is a good mechanic, and has been wrenching on MG and BMW for several years. I did get the bike back until something is heard from Italy, and they decide what to do.

[Johncolleary]

There was a recall on early 2000s Aprilias due to some having the oil tanks porous and would just ooze oil through the sides of the tank. 

[Kev m]

A few of years ago a board member (who hasn't posted in a year or two, but into whom I ran last summer) had a porous engine case on a V7 Classic.

Sadly, it took them MONTHS, but they did get it replaced and it has been fine since.

[TDF]

Have seen porous cases on Ural's for certain.  Situation normal for them though.  A real bear to keep clean.

TDF

[scra99tch]

Had one on an intake, probably caused the PO to sell the bike.  It was right behind the flange hole and you could only tell that it was there becuase of soot from it coughing.  JB weld and a reamer took care of it.

[sign216]

Lorazpam,

I've heard of this before on a Guzzi 750, but it was the rear drive casting that was porous and leaked.  A bear to track down, since it's "not the usual suspect."

[Matt Story]

I work for a company that builds assembly automation for automotive engines and transmissions.  It is common to leak test every aluminum case before assembly.  It is often done in a dunk tank.  Cases that need better quality are filled with helium and contained in a high vacuum while sniffing electronically for helium leaks.

So yes, but porous castings exist.  Maybe Aprilia should have a tighter quality control.

On a side note, it's impressive that the results of many (all?) such tests conducted during assembly are tracked throughout the assembly process, tied to the final assembly's serial number and stored through the life of the product.

Matt

[John in PA]

Wasn't this  big problem for the classic Brit-bikes before the demise of the original British motorcycle industry? (Current Triumphs obviously excepted)

[Triple Jim]

Porous castings can be sealed, but I guess if you're going to disassemble everything to seal it by vacuum impregnation, you might as well just replace the casting with one that isn't porous.

[jbell]

Many years ago my bike was weeping oil through one of the side cases.  After a thorough cleaning of the inside, I copper-coated it and never had a problem again with it.