• Remanufactured Dana Spicer DDP40 / DD404 forward differential with full Driver Controlled Locker (DCL) showing ring and pinion, power divider, and locker mechanism
  • Side view of remanufactured Dana Spicer DD404 forward tandem differential with power divider and Driver Controlled Locker
  • Top view of Dana Spicer DD404 differential showing large ring gear and carrier with orange paint protection
  • Angled view of remanufactured Dana Spicer DDP40 / DD404 forward differential highlighting internal gearing and locker components
  • Rear input side view of remanufactured Dana Spicer DDP40 / DD404 forward differential showing input yoke, power divider, and Driver Controlled Locker mechanism
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DS404

Quote Only, Call For Price - 419-522-3320

DDP40 | DD404 Front Differential | Dana Spicer | Eaton | Full Locker | *DPX Reman

DDP40 | DD404 Front Differential | Dana Spicer | Eaton | Full Locker | *DPX Reman

DDP40 | DD404 | Dana Spicer Forward Differential with Full Driver Controlled Locker (DCL) — Remanufactured by DPX (40K GAWR)

The Dana Spicer DDP40 / DD404 (also known as DD-404 or DDP40-FWD) is a heavy-duty forward tandem differential with integrated power divider and factory Driver Controlled Locker (DCL) — commonly referred to by drivers as a "Full Locker". Remanufactured in Mansfield, Ohio by Discount Parts Exchange - DPX. Every unit is torn down, cleaned, inspected, and rebuilt to your exact ratio with new bearings, seals, and critical wear components. The DCL system allows the driver to engage a full lock for maximum traction in slippery, off-road, or severe service conditions.

Call DPX to confirm: 419-522-3320.

Highlights

  • Model: DDP40 / DD404 Forward with Driver Controlled Locker (DCL / Full Locker)
  • Axle Family: Dana D344 / D404 / D405 / D454
  • GAWR: 40,000 lb
  • Design: Single-reduction hypoid gearing with integrated power divider + Driver Controlled Air Locker
  • Locker Type: Driver Controlled Locker (DCL) — full lock when activated by dash switch
  • Common Applications: Kenworth, Peterbilt, Volvo, Mack, Freightliner, International, Western Star, dump trucks, mixers, logging, heavy-haul, construction, and severe service
  • Dry Weight: ≈475 lb
  • Warranty: 12-month, unlimited mileage (parts-only)

Critical Specs & Related Parts

Item Specification / Part Number Notes
Axle Shaft Splines 41 —
Input Shaft Spline 2.274" – 44 Involute Spline —
Input Nut 128049 55 mm socket • Torque 840–1020 lb-ft
Input Seal 127591 —
Output Seal 127592 —
Output Nut 127588 55 mm socket • Torque 680–832 lb-ft

Tech Tip – Removing the Differential

Important: Before removing the axle shafts, apply shop air to the DCL cylinder to collapse the collar. This holds the collar in the collapsed position so the carrier slides out of the housing much easier.

Available Gear Ratios & Part Numbers (DDP40 / DD404 Forward)

Original kit numbers shown in parentheses where applicable.

DDP40 / DD404 Forward Gearsets
Ratio Kit P/N Ring Gear P/N (teeth) Pinion P/N (teeth)
2.64 211462 127387 (37) 127439 (14)
2.85 211463 127388 (37) 127440 (13)
2.93 509423 129532 (41) 129531 (14)
3.08 513386 127388 (37) 129716 (12)
3.25 513385 127389 (39) 130120 (12)
3.36 513384 127388 (37) 130121 (11)
3.42 504056 134327 (41) 134328 (12)
3.55 513383 127389 (39) 130122 (11)
3.70 513382 127388 (37) 130123 (10)
3.90 513381 127389 (39) 130124 (10)
4.11 513380 127388 (37) 130125 (9)
4.33 513379 130201 (39) 130126 (9)
4.63 513378 130196 (37) 129733 (8)
4.88 513377 130197 (39) 129735 (8)
5.29 513376 130196 (37) 129816 (7)
5.57 513375 130197 (39) 129820 (7)
6.17 513374 127390 (37) 129843 (6)
6.50 511571 129736 (39) 127454 (6)
7.17 511572 130178 (43) 130177 (6)

What’s Included

  • Remanufactured DDP40 / DD404 forward differential with power divider and Driver Controlled Full Locker rebuilt to your requested ratio by Discount Parts Exchange - DPX
  • 12-month, unlimited-mileage parts-only warranty
  • DPX tech support during installation and initial run-in

Core Exchange Policy

  • Required: Like-for-like, complete, rebuildable core
  • Deductions may apply for: Cracked housings; burnt/missing internals; low-lube or water damage; non-matching cores
  • Preparation: Core must be drained and palletized for pickup

Shipping Policy

  • Ships via LTL motor freight to verified commercial addresses only
  • No residential delivery — forklift or dock required at delivery

Image Disclaimer

Photos shown are representative; final appearance may vary by ratio and casting revision.

Call to Order

Call Discount Parts Exchange - DPX for pricing and ratio availability: 419-522-3320

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THE REMAN CENTER. INC. dba Discount Parts Exchange

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A trusted drivetrain partner since 1997

✅ Quality Gearing

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