Not sure Brian I didn't take it apart..wouldn't know what to look for anyway. Just slowly lost power. Welsh Will was unable to get it to shoot over about 10ftlb...
I was so happy with the recoil and accuracy in the garden but when shooting it at the club the problems became more obvious over 30 meters.
No diagnosis given, he spent hours on it but had to give up. Umarex exchanged immediately..went back today..