This is a guide to replacing Pella single-point mortise lock with a PZ measurement of 85mm and a backset of 55mm. The replacement kit used/depicted in this guide is part #40177 (lock case by itself without handleset, cylinder, etc. is part #40176).
This is the original lock and handleset (part #9099998). If your lockset does not have these measurements, this replacement kit will most likely not fit your lock.
Original Pella Lockset Components
Pella single-point lock body with 85mm handle-to-cylinder spacing (PZ) and 55mm backset
Front/faceplate view of pece A: 15/16 inch wide by 9-1/2 inches long with radial ends
Deadbolt strike plate: 1 inch wide by 7-3/4 inches long
Original handleset with 8-1/4 inches screw-hole spacing and 1-3/4 inch width; thumbturn requires special cylinder with square peg receiver
Pella special cylinder without thumbturn; for special Pella handleset with square peg on thumbturn
Replacement Kit Components
Single-point lock body with handle-to-cylinder (PZ) spacing of 85mm and 60mm backset
Front/faceplate view of piece A: 7/8 inch wide by 9-3/8 inches long with square ends
Deadbolt strike plate: 7/8 inch wide by 8-1/16 inches long
Replacement handleset with variable screw-hole spacing and width depending on which style is chosen. *NOTE: consider that width and length of new handleset need to be such that original screw holes and cut-out are covered, not exposed by new handleset. Available styles and their widths/lengths are listed below:
Congressional: 1.94 inches wide by 10.13 inches long
Westwood: 1.87 inches wide by 8.87 inches long
Villa: 1.88 inches wide by 10.94 inches long
Vintage: 1.56 inches wide by 9.06 long
Conventional: 1.31 inches wide by 9.30 inches long
Modern: 1.75 inches wide by 9.31 inches long
Silhouette: varying width changes from top to bottom of handle; 9.18 inches long
Coronet: 1.94 inches wide by 10.13 inches long
Ingress: 1.87 inches wide by 8.7 inches long
Cylinder with thumbturn; for standard handleset with euro-profile hole for cylinder and thumbturn
Remove handles on both sides first, then unscrew set screw just below deadbolt on edge of door.
Remove cylinder by pushing out through broad side of door through cylinder hole (lock must be unlocked).
Unscrew lock body from door edge and remove from door.
Insert new lock body in mortise and screw loosely in place. *Note: New lock body has square edges on faceplate instead of round; may need to chisel out door edge a little to fit new lock body.
Mark where cylinder hole may need to be enlarged slightly to accommodate new 60mm backset. Remove lockset and enlarge hole.
Reinstall lock and screw tightly in place.
Install spindle and handles in place so spindle fits through handle-hole and thumbturn hole is lined up with cylinder hole in lock body. Screw in place.
Install cylinder from the inside so key hole is on outside. Open door and install set screw just under deadbolt on edge of door.
There are three options when it comes to replacing your deadbolt strike plate (diagram below):
It is possible to reuse your original strike plate by moving it up or down with the door jamb to fit new lock. Alternatively, original strike plate may also be modified with a hack saw to fit new lock.
Or you can replace strike plate with new strike plate (included in kit #40177). *Note: new strike plate has squared ends and door jamb will have to be modified; old cut-out may be visible on door jamb under new strike plate.
Or new optional HOPPE strike plate (part #1963546) can be installed as an alternative; long enough and wide enough to cover old cut-out (HOPPE strike not included in kit).