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1.6 GPF Two-Piece Elongated Toilet with 12

Replacement Parts for the Kohler K-3978

There are 18 repair parts listed below for:

  • Manufacturer/Brand:
  • Model #:
  • Description:
  • Kohler
  • Kohler K-3978
  • 1.6 GPF Two-Piece Elongated Toilet with 12" Rough In from the Wellworth Collection

3 Steps to ordering parts

  • 1. Confirm you have chosen the correct model number.
  • 2. Browse the available parts below.
  • 3. Choose quantity, finish if needed and add to cart.
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Need to fix your Kohler K-3978? At, all of our replacement parts list below are 100% genuine Kohler products. Use these parts to repair your fixture and restore it to its original condition. Use our repair parts diagrams to find the exact part for your K-3978. We help make repairing your fixture easy when you shop with us.

The Kohler K-3978 has 18 repair items that are compatable with the following Kohler SKUs: K-3978-47, K-3978-96, K-3978-7, K-3978-NY, K-3978-95, K-3978-G9, K-3978-0 .

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Order K-3978 Replacement Parts

Qty Product Description Parts Diagram Part Reference #
Kohler 1013092 Part

Kohler 1013092** -

Product Features:

  • Bolt cap accessory pack only
  • Part numbers (1013092-0) and (1013092-96) have been replaced by (GP1013092)


View Diagram Page: 1 1013092**
Kohler 1057941 Part

Kohler 1057941 -

Locknut Assembly, Shank, Two-Piece (Replaces the 84678).

Finish: N/A

Price: $1.00

View Diagram Page: 1 1057941
Kohler 1138565 Part

Kohler 1138565** -

Replacement Cover, Tank, Toilet

Finish: Dune

Price: $26.20

View Diagram Page: 1 1138565**
Kohler 1145365 Part

Kohler 1145365 -

Replacement Flush Valve Kit, 1.6 GPF

Finish: N/A

Price: $14.80

View Diagram Page: 1 1145365
Kohler 32572 Part

Kohler 32572 - WASHER- .330 ID X 7/8 OD

Finish: N/A

Price: $1.00

View Diagram Page: 1 32572
Kohler 42397 Part

Kohler 42397 - SUPPLY NUT

Finish: N/A

Price: $1.50

View Diagram Page: 1 42397
Kohler 42398 Part

Kohler 42398 -


Finish: N/A

Price: $1.00

View Diagram Page: 1 42398
Kohler 50752 Part

Kohler 50752 - WASHER

Finish: N/A

Price: $1.00

View Diagram Page: 1 50752
Kohler 51533 Part

Kohler 51533 - NUT- .312-18UNC-2B

Finish: N/A

Price: $1.00

View Diagram Page: 1 51533
Kohler 51624 Part

Kohler 51624 - CLOSET TANK BOLT

Finish: N/A

Price: $2.10

View Diagram Page: 1 51624
Kohler 78132 Part

Kohler 78132 -


Finish: N/A

Price: $1.00

View Diagram Page: 1 78132
Kohler 83143 Part

Kohler 83143 -

Seal Diaphragm

Finish: N/A

Price: $3.90

View Diagram Page: 1 83143
Kohler 85307 Part

Kohler 85307 - WASHER- SHANK

Finish: N/A

Price: $1.00

View Diagram Page: 1 85307
Kohler GP1059291 Part

Kohler GP1059291 -

Seal Kit

Finish: N/A

Price: $6.90

View Diagram Page: 1 GP1059291
Kohler GP1083167 Part

Kohler GP1083167 -

Product Features:

  • Adjustalbe fill valve kit only
  • This part number (GP1083167) replaces part number (1085759)

Finish: N/A

Price: $14.99

View Diagram Page: 1 GP1083167
Kohler K-4198 Part

Kohler K-4198 -

Product Features:

  • Elongated bowl gives a modern and comfortable look and feel extending out an extra 1-1/2" compared to a round configuration
  • Covered under Kohler's 1-year limited warranty
  • Made from porcelain for that clean and classic look
  • Floor mounted installation for the standard, contemporary bathroom
  • Seat is not included - must be purchased separately

Product Specifications:

  • Overall Height: 14-1/2" (measured from the bottom of the base to the highest point on bowl)
  • Overall Length: 28-3/4" (measured from the back of the bowl to the front of the rim)
  • Overall Width: 15-1/2" (measured from the furthest point on the left to the furthest on the right)
  • Water Area: 11-1/4" x 8-1/4" (inner rim dimensions length X width)
  • Trapway (Discharged Passageway) Size:  2-1/8"
  • Distance Between Toilet Seat Installation Holes: 5-1/2"

About Kohler:

Gracious living is characterized by qualities of charm, good taste, generosity of spirit and the enhancement of nature. It is Kohler’s mission that you can improve your sense of gracious living with every experience you have with a Kohler product or service.

With everything that Kohler does it lives on the leading edge of design and technology, while maintaining a constant level of quality regardless of price. Kohler sets the standard of excellence in its field, and yet is constantly striving to improve.

From sustainable products in the kitchen and bath, to engines for lawn tractors and generators, to power systems that protect data centers and urban landscapes all over the world; this is what the Kohler Company is all about.


View Diagram Page: 1 K-4198
Kohler K-4468 Part

Kohler K-4468 -

1.6 GPF Tank from the Wellworth Collection

Exceptional Performance. Exceptional Value. Wellworth toilets have been an American benchmark for innovation and performance since 1936. With a new design in 2011, the Wellworth toilet brings and elegant flare that complements a wide range of bathroom designs.

  • 12" (30.5 cm) rough-in
  • Class Five - provides tremendous bulk waste flushing performance and best-in-class bowl cleanliness
  • 3-bolt Installation - Three pre-installed tank bolts save installation time
  • Canister flush valve provides smooth flushing actuation with consistent water usage, flush after flush
  • 1.6 gpf
  • Polished chrome trip lever


View Diagram Page: 1 K-4468
Kohler K-9379 Part

Kohler K-9379 -

Wellworth Reversible Trip Lever

Bring graceful lines and a streamlined design to your bathroom with Wellworth accessories, which incorporate a contemporary sensibility. This sturdy metal trip lever is designed for use with Wellworth and Highline two-piece toilets and works in either left- or right-hand configurations.

Kohler K-9379 Features:

  • KOHLER finishes resist corrosion and tarnishing, exceeding industry durability standards two times
  • Metal construction for durability and reliability
  • For use with the Highline Collection two-piece toilets
  • Can be used for left-hand and right-hand tank configurations
  • Modern design fits newer Wellworth toilets


View Diagram Page: 1 K-9379
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