That's a great price--and the part number GAD-136 is correct, as it corresponds to the MB number 1704100115 according to this reference table from the site of SGF's US-distributor: https://www.powertrainindustries.com...ber+Flex+Discs
As for whether or not SGF flex discs can be trusted: obviously, MB does not produce flex discs itself, just as it doesn't produce spark plugs, motor mounts, suspension bushings, shocks, fluids, etc. So who is the OE producer?
At least on my car the factory installed flex discs are from SGF. Moreover, while I have not held one in my hands yet, the "Lemfoerder" discs pictured on the internet also all show the "SGF" letters, not the Lemförder logo (which would be a small owl). A picture of a FEBI flex disc (of course FEBI is a(n upper market) reboxer): "SGF." (The W116 parts image thread
Further, some quotes from this thread (https://www.benzworld.org/forums/w124...y-uncle-5.html
SGF is the only branded MFG for these discs, meaning all aftermarket are reboxers.
When I got the (wrong) Lemforder's at the beginning of this thread they were actually SGF's. Lemforder, Febi, Jurid all put SGF's in their boxes.
SGF is the OE manufacturer of Mercedes flex disc's.
In this light, the claim on the amazon vendor site, which can also be found on the official US distributor site for SGF parts (https://www.powertrainindustries.com/news.htm
), according to which "SGF has manufactured over 90% of OEM flex couplers since 1946" might well be true. And all this would suggest that as long as you get the application-specific SGF disc from a reliable vendor, you are golden.
On the other hand, obviously no harm will be done by buying a (SGF) flex disc through the MB dealer network--dealers and their employees need to earn a living as well.