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Quick Answer
Security Parts stocks 33 replacement parts for the LCN 4020T track-arm surface door closer. The key components are the 3077T standard track arm (180-degree swing), four 3038-family tracks (standard, hold-open, bumper, and hold-open plus bumper), the 3034 and 3034H track rollers, the 18 drop plate for narrow head frames, and 10 screw pack variants covering all substrates and thru-bolt configurations. The 4020T cylinder is available in spring sizes 1, 3, and 4 based on door width. All 33 parts are confirmed in stock.
What Is the LCN 4020T?
The LCN 4020T is the track-arm (parallel arm) configuration of the LCN 4020 surface-mounted commercial door closer. Instead of connecting from the closer body to a shoe on the door frame, the 4020T uses a horizontal track mounted on the door surface. The arm extends from the closer spindle and slides inside that track to control the door arc on every cycle.
The track-arm configuration suits doors that swing toward the closer (the same side the closer body is mounted on), and it is preferred when a parallel-arm layout is needed for clearance, aesthetics, or ADA compliance. The 4020T can be ordered with an opening force of less than 5.0 lbs on a 36-inch door, making it suitable for ADA-compliant installations.
How Do I Know If I Have a 4020T or a Standard 4020?
Look at the door surface when the door is open. If you see a horizontal track channel mounted across the door with an arm sliding inside it, you have the 4020T. If there is only a straight arm going from the closer body to a shoe on the frame or soffit, you have the standard 4020 and need different parts.
The closer body label also identifies the model. The label is on the underside or end of the closer body and will show 4020T as the series. For a full family comparison, see the LCN 4000 series parts guide.
What Spring Size Does the LCN 4020T Come In?
The LCN 4020T cylinder is available in three spring sizes: 1, 3, and 4. Spring size is selected based on door width. The LCN size selection table maps door widths to recommended sizes:
| Spring Size | Typical Application | Notes |
|---|---|---|
| Size 1 | Narrower, lighter-use doors | ADA low-force option; can deliver less than 5.0 lbs opening force on 36-inch door |
| Size 3 | Medium-width commercial doors | Most common size for standard office and corridor doors |
| Size 4 | Wider or heavier doors | Higher spring tension; appropriate for wider openings or windy exterior applications |
The spring size is stamped or labeled on the closer body. Confirm the size before ordering a replacement cylinder or screw pack, since some fastener packs are size-specific.
What Clearance Does the LCN 4020T Need Behind the Door?
The LCN 4020T requires a minimum of 1-1/2 inches (38mm) of clearance between the back of the door and the wall or any obstruction for 90-degree or 180-degree swing. If the door cannot open to that clearance, the track arm will bind or the arm will not reach its maximum rotation. Measure this before installing a new track or replacing an arm to confirm the door geometry supports the intended swing angle.
LCN also recommends ANSI/SDI-100 reinforcing for hollow metal doors at the closer and track mounting locations. This is a practical note for contractors: without proper reinforcing, hollow metal doors can pull or deform at the fastener locations under repeated closer cycling, causing misalignment over time.
LCN 4020T Parts by Component Category
Track Arm
LCN 4020T-3077T Standard Track Arm, 180-Degree Swing. The primary arm component for the 4020T. View product page.
| Part Number | Description | Notes |
|---|---|---|
| 4020T-3077T | Standard Track Arm, 180-Degree Swing | Handed (H) -- specify left hand (LH) or right hand (RH) when ordering. Roller not included with arm. |
The arm is handed, meaning left-hand and right-hand versions are different parts. Before ordering, confirm the hand of your door: standing in the opening looking toward the outside, a right-hand door has the hinges on the right. The arm screw (4020T-159) that fastens the arm to the closer spindle should be replaced whenever the arm is replaced, since stripped arm screws are a common cause of arm looseness.
Tracks
LCN 4020T-3038HB Standard Track with Bumper and Hold-Open. View product page.
| Part Number | Description | Use When |
|---|---|---|
| 4020T-3038 | Standard Track, Non-Hold-Open | Door returns to closed automatically; no open-position stop required. Will accept hold-open clip or bumper assembly as optional additions. |
| 4020T-3038H | Standard Track with Hold-Open | Hold-open clip installed; door holds at a set open position. Will accept bumper assembly. |
| 4020T-3038B | Standard Track with Bumper | Bumper assembly installed to limit swing; no hold-open. Will accept hold-open clip. |
| 4020T-3038HB | Standard Track with Bumper and Hold-Open | Both hold-open and bumper assembly installed. |
All four track variants are non-handed, meaning the same track fits left-hand and right-hand doors. Finish must be specified when ordering (indicated by (F) in the LCN parts list).
Important: The track bumper assembly (4020T-169) is designed to assist backcheck and limit the maximum door opening swing. It does not replace an auxiliary stop. If the door is swinging hard against a wall or surface, an auxiliary wall or floor stop should also be installed.
Track Rollers
LCN 4020T-3034H Hold-Open Track Roller. Required when the installed track is a hold-open variant. View product page.
| Part Number | Description | Paired With |
|---|---|---|
| 4020T-3034 | Track Roller (standard) | 3038 or 3038B (non-hold-open tracks) |
| 4020T-3034H | Hold-Open Track Roller | 3038H or 3038HB (hold-open tracks); different roller profile that engages the hold-open clip |
| 4020T-3064H | HO Roller and Clip (complete hold-open assembly) | When replacing both roller and hold-open clip at the same time |
| 4020T-425 | Roller Locking Screw | Secures roller to arm end; replace whenever roller is replaced |
The LCN 4020T roller is a quiet, low-friction assembly with a shoulder dimension of 1/16 inch (2mm). The standard (3034) and hold-open (3034H) rollers have different profiles and are not interchangeable. Using a standard roller in a hold-open track will prevent the door from latching open at the hold-open point.
Hold-Open Components
| Part Number | Description | Function |
|---|---|---|
| 4020T-3054 | Hold-Open Clip | Mounts in track to provide hold-open function. Hold-open point is controlled by clip location within the track channel. |
| 4020T-3064H | HO Roller and Clip | Combined replacement of roller and clip when both components need replacing |
Drop Plate
| Part Number | Description | Required When |
|---|---|---|
| 4020T-18 | Drop Plate, Narrow Top Rail or Flush Ceiling | Head frame is less than 3-7/8 inches (98mm) wide. The drop plate itself requires a minimum frame face of 1-3/4 inches (44mm). |
Covers, Caps, and Hardware
LCN 4020T-72 Standard Cover. Handed part -- specify finish and hand when ordering. View product page.
| Part Number | Description | Notes |
|---|---|---|
| 4020T-72 | Standard Cover | Handed (H), finish required (F). Standard plastic cover. |
| 4020T-72MC | Metal Cover | Handed (H), finish required (F). Required for plated finishes and custom colors; more durable than plastic. |
| 4020T-73 | End Cap | Finish required (F). Two required per closer; sold individually. |
| 4020T-141-2 | Plug | Finish required (F). Four required per closer; sold individually. Seals unused adjustment ports. |
| 4020T-169 | Bumper Assembly | Mounts in track to assist backcheck and limit maximum opening. Consists of bumper, bumper post, and mounting screw. Does not replace an auxiliary stop. |
| 4020T-31 | Cover Screw | Fastens cover to closer body. |
| 4020T-159 | Arm Screw | Fastens arm to closer spindle at pre-load position. Replace when stripped. |
Screw Packs
The LCN 4020T ships standard with a Self-Reaming and Tapping (SRT) screw pack containing Phillips head screws. Ten screw pack variants cover all mounting substrates, thru-bolt requirements, and hold-open track configurations.
| Part Number | Description | Use For |
|---|---|---|
| 4020T-WMS | Wood-Machine Screws | Standard track, wood or light metal substrate |
| 4020T-SRT | Self-Reaming Tapping Screws | Standard track, hollow metal or steel substrate |
| 4020T-TORX | Torx Machine Screws | Standard track, Torx head for tamper resistance |
| 4020T-TBWMS | Thru-Bolt Wood-Machine Screws | Standard track, thru-bolt mounting, wood |
| 4020T-TBSRT | Thru-Bolt Self-Reaming Tapping Screws | Standard track, thru-bolt mounting, steel |
| 4020T-TBTRX | Thru-Bolt Torx Machine Screws | Standard track, thru-bolt mounting, Torx head |
| 4020T-HWMS | HO Wood-Machine Screws | Hold-open track, wood substrate |
| 4020T-HSRT | HO Self-Reaming Tapping Screws | Hold-open track, steel substrate |
| 4020T-HTBWMS | HO Thru-Bolt Wood-Machine Screws | Hold-open track, thru-bolt, wood substrate |
| 4020T-HTBSRT | HO Thru-Bolt Self-Reaming Tapping Screws | Hold-open track, thru-bolt, steel substrate |
| 4020T-HTORX | HO Torx Machine Screws | Hold-open track, Torx head |
| 4020T-HTBTRX | HO Thru-Bolt Torx Machine Screws | Hold-open track, thru-bolt, Torx head |
Standard LCN thru-bolts install on 1-3/4 inch (44mm) thick doors with 1/4-20 machine screws. Optional thru-bolt sizes for 1-5/8 inch (41mm) or 1-3/8 inch (35mm) door thickness must be specified when ordering.
Troubleshooting: Why Is My LCN 4020T Not Working Properly?
Why Is My LCN 4020T Door Not Closing?
If the door is not closing fully, check the following in order:
- Check the closing speed valve. Turn all regulating valves clockwise until they stop, then open each valve 1-1/2 turns as a starting point. Closing speed is typically the main valve.
- Inspect the roller and track. A worn roller that skips in the track can prevent the closer from pulling the door shut.
- Check the spring size. If the spring is underrated for the door weight or width, the door will not close against wind pressure or door seal resistance.
- Verify the arm is not bent. A bent 3077T arm sits the door at an angle that may cause the latch to miss the strike.
Why Is My LCN 4020T Arm Clicking or Squeaking?
Clicking, squeaking, or grinding as the door swings is almost always a worn track roller. The roller runs inside the track channel on every cycle and is the highest-wear component in the system. Replace the 3034 (standard) or 3034H (hold-open) roller first. If the noise continues after roller replacement, the track channel interior may be scored or grooved and the track itself should be replaced.
Should I Rebuild or Replace My LCN 4020T?
In most field situations, replacing individual components is the correct approach rather than replacing the full closer. A new LCN 4020T closer costs several hundred dollars. If the symptoms are a worn roller, a bent arm, or a damaged track, replacing only those parts is the practical solution.
Full closer replacement makes more sense when the closer body itself is leaking hydraulic fluid at the pinion or end cap, when the spring is broken internally, or when the closer has sustained physical damage to the housing. The hydraulic fluid in an LCN closer must not be refilled in the field; if the body is leaking, the closer needs to be replaced.
How Do I Install the LCN 4020T Arm and Track Roller?
The LCN 4020T installation sequence from the official instructions is as follows:
- Assemble the roller into the track channel before mounting the track to the door.
- Attach the arm to the closer spindle at the pre-load position (15 degrees from the door face). Secure with the arm screw (4020T-159).
- Open the door approximately 30 degrees, pull the arm over the top of the door, and connect the arm to the track roller as shown in the installation template.
- Adjust the closer as needed for closing speed, latch speed, and backcheck.
For step-by-step adjustment guidance, see the how to adjust a commercial door closer guide. For full installation guidance, see the how to install a commercial door closer guide.
How to Specify LCN 4020T Parts: Finish and Hand Requirements
Several LCN 4020T parts require finish and hand to be specified at order time. The LCN parts list marks these with (F) for finish and (H) for hand:
- Finish (F): The cover (72, 72MC), end caps (73), and plugs (141-2) require a finish specified at order. Common LCN finishes include 689 (aluminum), 690 (dark bronze), 693 (black), and others. Match the existing closer finish when ordering replacement covers.
- Hand (H): The arm (3077T) and covers (72, 72MC) are handed. Specify LH (left hand) or RH (right hand) to match the door. Standing in the opening and looking toward the outside: hinges on the right = right-hand door.
- Tracks and rollers: Non-handed. The same track and roller fit both left-hand and right-hand doors.
LCN 4020T vs 4010T vs 4020: Which Parts Are Shared?
| Feature | LCN 4020T | LCN 4010T | LCN 4020 (standard arm) |
|---|---|---|---|
| Mounting type | Track arm (parallel) | Track arm (parallel) | Standard arm |
| Spring sizes | 1, 3, 4 | 1, 3 | 1, 3, 4 |
| Track parts shared | 3038 family | Same 3038 family (verify prefix) | No track -- uses arm shoe |
| Parts interchangeable | With 4010T: verify prefix before ordering | With 4020T: verify prefix before ordering | Not interchangeable with 4020T |
For LCN 4010T parts, see the LCN 4010T parts guide. For the full family comparison, see the LCN 4000 series guide.
Complete LCN 4020T Parts Reference Table
| Part Number | Description | Category | Handed/Finish |
|---|---|---|---|
| 4020T-3077T | Standard Track Arm, 180 Degree Swing | Arm | H, F |
| 4020T-3038 | Standard Track, Non-Hold-Open | Track | F |
| 4020T-3038H | Standard Track with Hold-Open | Track | F |
| 4020T-3038B | Standard Track with Bumper | Track | F |
| 4020T-3038HB | Standard Track with Bumper and Hold-Open | Track | F |
| 4020T-3034 | Track Roller | Roller | -- |
| 4020T-3034H | Hold-Open Track Roller | Roller | -- |
| 4020T-3064H | HO Roller and Clip | Roller / HO | -- |
| 4020T-425 | Roller Locking Screw | Roller | -- |
| 4020T-3054 | Hold-Open Clip | Hold-Open | -- |
| 4020T-18 | Drop Plate, Narrow Top Rail or Flush Ceiling | Drop Plate | F |
| 4020T-72 | Standard Cover | Cover | H, F |
| 4020T-72MC | Metal Cover | Cover | H, F |
| 4020T-73 | End Cap (2 required, sold individually) | Cover | F |
| 4020T-141-2 | Plug (4 required, sold individually) | Cover | F |
| 4020T-169 | Bumper Assembly | Stop | -- |
| 4020T-31 | Cover Screw | Fastener | -- |
| 4020T-159 | Arm Screw | Fastener | -- |
| 4020T-WMS | Wood-Machine Screws | Screw Pack | -- |
| 4020T-SRT | Self-Reaming Tapping Screws | Screw Pack | -- |
| 4020T-TORX | Torx Machine Screws | Screw Pack | -- |
| 4020T-TBWMS | Thru-Bolt Wood-Machine Screws | Screw Pack (TB) | -- |
| 4020T-TBSRT | Thru-Bolt Self-Reaming Tapping Screws | Screw Pack (TB) | -- |
| 4020T-TBTRX | Thru-Bolt Torx Machine Screws | Screw Pack (TB) | -- |
| 4020T-HWMS | HO Wood-Machine Screws | Screw Pack (HO) | -- |
| 4020T-HSRT | HO Self-Reaming Tapping Screws | Screw Pack (HO) | -- |
| 4020T-HTORX | HO Torx Machine Screws | Screw Pack (HO) | -- |
| 4020T-HTBWMS | HO Thru-Bolt Wood-Machine Screws | Screw Pack (HO/TB) | -- |
| 4020T-HTBSRT | HO Thru-Bolt Self-Reaming Tapping Screws | Screw Pack (HO/TB) | -- |
| 4020T-HTBTRX | HO Thru-Bolt Torx Machine Screws | Screw Pack (HO/TB) | -- |
| 4020T-Rebox Kit | Rebox Kit, Box and Instruction Sheet | Documentation | -- |
| 4020T-Flat Box | Flat Box with Label | Documentation | -- |
| 4020T-Instruction Sheet | Instruction Sheet | Documentation | -- |
Where to Order LCN 4020T Parts
Security Parts stocks all 33 LCN 4020T replacement components verified in stock and ready to ship. Call 845-935-0301 for pre-order compatibility support or to confirm a part number, finish, hand, or spring size before placing an order. For the broader LCN closer parts catalog, see the door closers parts guide. For help selecting the right LCN closer or spring size for a new opening, see the LCN commercial door closer selection guide and the commercial door closer sizing guide. For related LCN track-arm closer parts, see the LCN 4050AT parts guide and the LCN 4040XP parts guide.
About This Guide
Written by the Security Parts team. Security Parts has supplied commercial door hardware parts to locksmiths, general contractors, facilities managers, and security integrators since 2001. All 33 LCN 4020T parts listed in this guide are verified in stock with same-day shipping on stocked components. Call 845-935-0301 for pre-order compatibility support. For related LCN closer guides, see the LCN 4000 series parts guide and the LCN 4840 parts guide.