Sachs Clutch: Longevity and date code questions

[Luis A.]

HI guys,

When I bought my car in 2011 it had 107,000 Kms on it. It now has ~145,000 Kms (~90,000 miles) on it, so I've owned it for 24,000 miles. I have not replaced the clutch and I have no evidence one way or another the prior owner did, but doubt it as he was a 'low maintenance' kind of guy and also put very few miles on it.. I take about a million pictures any time I do anything to the car but incredibly, when I rebuilt the engine in 2014 I did not take ONE picture of the pressure plate friction surface or the clutch disk. I gotta believe it must've looked pretty good to me or I would have replaced it, but I can't recall... I do have a picture of the outside of pressure plate and I am wondering if anyone can tell by the markings and appearance how old it might be. I'm tempted to say the "529" stamp is a date code, week 52 of year "9" (1999? before PO bought it in 2001?). It says "Made in Germany" and I suspect these haven't been made in Germany in a long while.

Take a look:

I have no indication the clutch or TO bearing are not working well but with the Europe trip next year I am thinking it may be smart to replace it now... So maybe there's my answer right there... Thoughts?

 

[Luis A.]

In the best tradition of answering one's own question... Below is what the shop manual states. Should've looked there.

The reverse test is interesting. Can anyone confirm that is a reliable measure of wear? It seems to me that would only indicate a pressure plate that is lazy and not completely lifting off the friction disc... correct?

In addition, the specs reference a green color code which is actually present on my existing pressure plate. I would think the color code thing also fell off a while back, just like it did for piston tolerances.

 

[deQuincey]

always giving us useful information luis, thank you

 

[Peter Coomaraswamy]

Luis, that is interesting. It never occurred to me to check clutch wear by measuring the thrust rod distance. I think that more than anything else the driving habits of the owners determine the wear over time of the clutch plates/surfaces. Also, the type of driving- city or highway. My e36 M3 5-speed has 215K on the original clutch. The PO drove the car from Austin to South Texas regularly, as a result there are lots of rock chips in the front paint but everything else is in excelent condition. ( I did replace the suspension and entire cooling system with stock components due to age though). I would wait until I felt slippage before replacing my clutch- unless the engine were out of the car