ocles_inc

I am in the process of fixing up a ZF 5HP-24A transmission as used in a 2000 Audi A6 Quattro 4.2 V8. It has a broken part: the clutch “A” drum and input shaft. A helpful friend found and sold me a used part, allegedly an “original equipment of the manufacturer” quality item, yet it did not look identical to the part that I already had. The part sent by my friend had 12 markings at the bottom, almost like the markings on the face of an analog clock.

I understand that there are some decent-quality made-in-the-US aftermarket drums, and some not-so-decent-quality made-in-China aftermarket drums. Really, I wanted to use a made-by-ZF drum ... original equipment of the manufacturer.



I took some pictures and sent them to the Eriksson industries, the ZF distributor in Connecticut. Nat Wentworth, there, is wonderfully insightful and helpful. He explained that the markings are an indication of an updated design.

As I understand the history of this part, there were concerns about the drum failing. Initially, the premise was that a stronger design was needed, until it became apparent that the amount of hydraulic pressure in a spike sent through by a worn pressure regulator is basically an unstoppable force. The better approach was to renew a worn pressure regulator preemptively rather than trying to beef up the drum design. The latter might be likened to building a better sandcastle upon hearing the news that a title wave is imminent.

That's not to say that the design and strength of this part doesn't matter ... it very much does. For example, someone put, as far as I can tell, an inferior-quality clutch “A” drum into the transmission of the Audi that needs this repair. The input shaft (part of the clutch “A” drum) had sheared or snapped right off.

~Tanya

4Driver4

You post some interesting stuff. :-)

ocles_inc

Yay! :-)