The Von Duprin 050404 is the OEM center case kit for the 33/35A Series 3327A and 3527A narrow style Surface Vertical Rod (SVR) exit device, supplied with less cover. It replaces the complete internal center case mechanism without including the cosmetic cover plate. This configuration exists for installations where the existing cover is undamaged but the internal case mechanism has failed or worn beyond service life. You keep the existing cover, replace the internals. The kit covers both the panic (standard) and fire-rated (-F) configurations of the 3327A and 3527A.

The center case is the core of any SVR exit device. Every functional element of the 3327A/3527A pushpad actuation, latch bolt retraction, rod attachment, spring return, fluid dampener, and all electrical option interfaces is housed in or connected through the center case. When the center case fails, nothing else matters. This kit restores full device function without replacing the pushpad, trim, rods, strikes, or the complete device assembly.

Von Duprin 33A Narrow Center Case: 3327A vs 3527A Distinction

The 050404 center case kit covers both the 3327A (33A Series) and 3527A (35A Series), but these two models have a visible case difference. The 3527A has a smooth mechanism case. The 3327A has a grooved mechanism case. Both share the same internal mechanism and the same center case kit part number the 050404 because the internal components are identical. The cosmetic difference is in the case surface finish, which is part of the cover (not included in this kit). This is why ordering less cover makes sense for a field replacement: the cover matches the installed device finish, and retaining the existing cover preserves the visual match without sourcing a finish-specific replacement.

The 3327A/3527A narrow stile design fits door stiles as narrow as 1-3/4" (44mm) on panic configurations. Fire-rated versions require a minimum stile width of 2-3/16" (56mm). Both versions are non-handed; the device installs on any door hand without modification with the exception of installations using the SS (Signal Switch) electrical option, which requires handing to be specified.

Von Duprin Center Case: What the 050404 Kit Replaces

The 3327A/3527A center case houses the entire operating mechanism of the SVR device. Inside the case: the pushpad actuating lever that converts pushpad depression into rod and latch movement, the deadlocking latch bolt retraction linkage (the deadlocking latchbolt is a standard feature on 33/35A Series that prevents forced latchbolt retraction), the spring mechanism for pushpad return, and the fluid dampener. The fluid dampener is a key Von Duprin 33/35A Series specification point; it decelerates the pushpad on its return stroke, eliminating most noise associated with exit device operation. This is standard on all 33A/35A Series devices and is part of the center case assembly.

The center case also provides the attachment points for the top and bottom vertical rods. Standard rods are 1/2" square tubing and accommodate 7' doors. The top rod is 34-15/16" and the bottom rod is 31-1/4" for standard height doors. Extension rods available in 1' and 3' lengths are added for doors over 7', and one-piece top rods are available for 8' to 10' door openings.

Von Duprin Exit Device Parts: 3327A/3527A Electrical Options

The center case provides the mounting positions and wiring connections for all 3327A/3527A electrical options including LX (latchbolt monitor switch), RX (pushpad monitor switch), RX2 (double pushpad monitor switch), SS (signal switch), EL (electric latch retraction), and ALK (alarm exit kit). If the installed device has any of these options, confirm the 050404 kit includes the appropriate connection provisions before installation.