Lock Nut

Enhance the performance of your heavy equipment with Case Construction Lock Nut #43440. Designed for durability and reliability, this essential component ensures secure fastening, providing peace of mind during demanding operations. Perfect for maintaining your machinery’s efficiency and safety.

Compatible equipment

This part fits BACKHOE LOADER, 2WD - TIER 4B - MY19, WHEEL LOADER - STAGE V - TS - ZBAR, CASE CRUZ-AIR WHEELED EXCAVATOR, CASE CRAWLER EXCAVATOR - DUAL POWER ELECTRIC & DIESEL ENGINE, CASE LONG TRACK/TURNABLE LEVELER CRAWLER EXCAVATOR, STD LINKAGE WHEEL LOADER STAGE 5, CASE CRAWLER TRACTOR, COMPACT WHEEL LOADER TIER 3, CASE UNI-LOADER SKID STEER LOADER, COMPACT WHEEL LOADER HS, ZB, COMPACT WHEEL LOADER HSP, ZB, COMPACT WHEEL LOADER STD EVO, ZB, BACKHOE, COMPACT WHEEL LOADER HPS EVO, XR, COMPACT WHEEL LOADER HSP EVO, ZB, COMPACT WHEEL LOADER STD, XR, CASE SKID STEER LOADER, COMPACT WHEEL LOADER HS, ZB - STAGE V, CASE LONG TRACK CRAWLER TRACTOR, CASE CONSTRUCTION KING LOADER BACKHOE, IND - CASE CRAWLER TRACTOR, LOADER LANDSCAPER, TRACTOR LOADER BACKHOE, ELECTRIC FOUR WHEEL DRIVE, SERIES 2 LOADER BACKHOE - ASN JJG0239360, BACKHOE LOADER, BACKHOE LOADER, 2WD - TIER 4B - MY18, BACKHOE LOADER, 4WD - TIER 4B - MY18, BACKHOE LOADER, 4WD - TIER 4B - MY19, CASE SUPER-E CONSTRUCTION KING LOADER BACKHOE, CASE SUPER-K CONSTRUCTION KING LOADER BACKHOE, LOADER BACKHOE - BSN JJG0239361, BACKHOE LOADER - WIDE TRACK, BACKHOE LOADER, 4WD - WIDE TRACK - TIER 4B - MY18, BACKHOE LOADER, 4WD - WIDE TRACK - TIER 4B - MY19, CASE CONSTRUCTION KING FORKLIFT, CASE FORKLIFT, TURBO LOADER BACKHOE, LOADER BACKHOE, SERIES 2 LOADER BACKHOE - ASN JJG0210575, CASE TURBO HORIZONTAL DIRECTIONAL DRILLING MACHINE, CASE WHEEL LOADER, SERIES 1 CRAWLER - 07/01/2002 - 01/31/2005, CASE TRENCHER, CASE SERIES-2 TELESCOPIC HANDLER, CASE TELESCOPIC HANDLER, CASE TIER-2 TELESCOPIC HANDLER, 4WD MOTOR GRADER ELECTRO-HYDRAULIC - STAGE V, 4WD MOTOR GRADER MY20 - STAGE V, 6WD MOTOR GRADER ELECTRO-HYDRAULIC - STAGE V, AWD MOTOR GRADER MY20 - STAGE V, MOTOR GRADER - ASN 020001, MOTOR GRADER TIER 2- BTW 020101-020187, CASE TURBO TRENCHER, CASE CRAWLER EXCAVATOR, CASE TURNTABLE LEVELER CRAWLER EXCAVATOR, CASE EXCAVATOR - TILTING TOOL ATTACHMENT W/QUICK COUPLER, COMPACT WHEEL LOADER STD, ELECTRIC, ZB, ENGINE, SKID STEER LOADER, SKID STEER LOADER - NRC, SKID STEER LOADER - TIER 3 - ROW, SKID STEER LOADER - TIER 4F - NA, SKID STEER LOADER - S5 NA, REGULATED NA - TIER 4 - MY26, REGULATED NA, TIER 4 - MY26, MINI TRACK LOADER 1000 - STAGE V, COMPACT TRACK LOADER - TIER 4F - NA, CASE UNIT LOADER including models 580N EP, 1021G2, 1085B, 1085C, 1086B, 1088, 1121G2, 1150E, 1150G, 1150H, 1155E, 121E SERIES 3, 1550, 1840, 21E SERIES 3, 221E SERIES 3, 221F, 221G, 26D, 321E SERIES 3, 321F, 321G, 35C WL, 40XT, 421G.

Frequently asked questions

What is the part number?

The manufacturer part number is 43440.

Is this a genuine OEM part?

Yes. Southeastern Equipment stocks OEM and quality aftermarket parts for heavy equipment. Contact us if you need a specific OEM source or aftermarket option.

Will this fit my machine?

See the compatible equipment list above. If your model is not listed, call us with your machine's serial number and we can confirm.

Where does this ship from?

Southeastern Equipment Company ships parts nationwide from our US warehouse. Orders placed before 2 PM ET typically ship same day.

Free pickup at any of our 17 branches across Ohio, Indiana, Michigan, and Kentucky. Select your preferred branch at checkout.

30-day no-fault returns. Bought the wrong part? Send it back for a full refund — no restocking fees, no minimums.