Ordered 2 of the SM5640 KYB strut mounts for my Eibach Pro lift kit.

They arrived today and hmmmm...the 2 mounts are different but in identical boxes though.

The one I am suspect of looks like it would work BUT>

The studs are 9.8 strength but the better looking one is 10.9 (stronger).

The supplied nuts have the same interior thread but the flange diameter and wrench size are smaller.

The rubber parts just look like lesser quality.

The one I think is genuine has a part number on the rubber spring seat- no number on the bad one.

The bad one has the greek letter Epsilon with an arc above it and below it and the registered trade mark stamp. A search of the US registered trademark database does not turn this up.

The suspect one has the part number SMT7921 on it- a search cannot find this number anywhere.

Bought at Advance Auto Parts, just got off chat with them- they said to take it to a store and swap it- uh no none of the AA's in my area carry this part- it must be ordered.

I just ordered 2 more- be interesting to see what I get. Once I sort this 2 of them will be returned.

Stay tuned!

Just replaced the KYB tophats in my 4th gen couple weeks ago. Something I ran into you might also: my originals had no rubber biscuit up inside the "hat", but the new ones have a 5/8" thick rubber biscuit molded in. So need to remove the lower rubber bushing off your shock, leave metal washer in place and install that way or your shock stud won't protrude enough through the hat for bushing/washer/nut on the top side.

Well the 2 replacement KYB top hats arrived- same lesser quality as the one I referenced in the 1st post of this thread. Weaker studs and undersized nuts.
If I get my stock struts off in time to be in the return window I may just use them with only 800 mi on them.

Then return all of the KYB stuff especially the 3 lower quality parts.

Apologies for resurrecting an old thread, but this is the only one that comes up if you search for SMT7921.

I recently ran into the same issue and reached out to KYB technical support to check if these are in fact real KYB parts. The set I received have the following part numbers on them:

• SMT7921
• SA2304 C

KYB responded quickly and confirmed that these are genuine KYB parts, and that the numbers we see match their internal stamping numbers.

Hopefully this helps others who run into this issue in the future.