Abstract: In a lift arm structure for a bucket, for instance on a loader-type vehicle, a service support is provided to block the lift arm in the extended position during servicing and repairing either of the lift arm structure or of parts in close proximity to the lift arm structure. The service support is U-shaped in configuration so as to straddle the rod of the lift cylinder when said lift cylinder is substantially completely extended. Pads are provided on the end of the service support to contact the mounting bracket for better distribution of the loads on the service support. Attachment members are mounted on the service support and engage a plate assembly bridging the open space between the sides of the service support so that with the service support in position on an extended cylinder rod, the attachment members and plate assembly lock the service support on the cylinder rod.