Wait a minute here. The 1550 SINGLE speed PTO uses a dry PTO clutch. It uses a sealed throwout bearing the same as a 1600. The 1650 and all the 1550 DUAL speed PTO&quot;s use a wet multiple disk clutch. The clutch disks in your 1550 are the same as used in many Olivers such as the 66 through the 880. They use a different throwout bearing. I have built some of those parts up before and then ground (machined) them to fit.