537185801 Bump Knob - Fits Husqvarna T35 Trimmer Head (2003-05, 2005-01, 2007-04) - 4 Pack
SKU: 32455411855

537185801 Bump Knob - Fits Husqvarna T35 Trimmer Head (2003-05, 2005-01, 2007-04) - 4 Pack

Sale price$13.53 Regular price$15.03
Save 10%

Shipping Estimate
USA
  • USA
  • CAN

Ships within 48 hours · Estimated delivery Jul 5 - Jul 10

Promo Codes Available:

For Your Every Summer RSVP, with Code: SUMMER15

Description

537185801 Bump Knob - Fits Husqvarna T35 Trimmer Head (2003-05, 2005-01, 2007-04) - 4 Pack537185801 Bump Knob Replacement Key Features High Impact Blue Polymer: Manufactured from a high density, abrasion resistant plastic specifically designed to withstand thousands of high velocity "bumps" against asphalt, gravel, and packed soil. Reinforced Structural Ribbing: The internal geometry features reinforced walls to prevent the knob from cracking or shattering under the extreme centrifugal force of commercial grade trimmers. Precision Spring

537185801 Bump Knob Replacement

Key Features

  • High-Impact Blue Polymer: Manufactured from a high-density, abrasion-resistant plastic specifically designed to withstand thousands of high-velocity "bumps" against asphalt, gravel, and packed soil.
  • Reinforced Structural Ribbing: The internal geometry features reinforced walls to prevent the knob from cracking or shattering under the extreme centrifugal force of commercial-grade trimmers.
  • Precision Spring Seating: Engineered with a centered internal recess to perfectly secure the T35's heavy-duty spring, ensuring a consistent and responsive line-advancement "snap" every time.
  • Commercial-Grade Multi-Pack: This 4-piece kit provides a cost-effective solution for landscaping fleets and large residential properties, ensuring you always have a spare on hand to prevent downtime.
  • Snap-In Tool-Free Installation: Designed as a direct-fit replacement that clicks into the existing T35 housing by hand, allowing for rapid field repairs without the need for specialized tools.

Replaces / Cross-Reference Part Numbers

  • 537185801

Compatibility & Fitment

This bump knob is the standard replacement for the professional "T35" series trimmer heads. Key compatible models include:

  • Husqvarna 100/200 Series: 123L, 123LD, 225L, 232L, 232R.
  • Husqvarna 300 Series: 322L, 323L, 324Lx, 325L, 325Lx, 326L, 326Lx, 327LS.
  • Husqvarna 500 Series: 522L, 525L, 525LS, 525LST, 535LS.
  • Historical Production Dates: Compatible with T35 heads manufactured during the 2003-05, 2005-01, and 2007-04 production cycles.
  • Note: Specifically for the T35 head. If you have the smaller T25 or larger T45, this knob will not fit correctly.

When to Replace

  • Worn-Through Bottom: The center of the blue knob has ground down from pavement contact to the point where the internal metal spring is visible or falling out.
  • Broken Retaining Tabs: The plastic clips that lock the knob into the housing have snapped, causing the knob to fly off while the trimmer is spinning at high RPM.
  • Seized Mechanism: Significant buildup of dried sap, dirt, and debris has fused the knob to the internal spool, preventing it from releasing new line.
  • Rounded Indexing Teeth: The internal plastic "teeth" that click against the spool have rounded off, causing the head to dump all the line at once during use.
  • Visible Stress Fractures: White lines or cracks appearing in the blue plastic, indicating the material has become brittle and is prone to catastrophic failure.

Installation Tips

  • Clean the Housing: Before installing the new knob, use a stiff brush or screwdriver to remove all dried grass and mud from the locking slots and spring area to ensure a 100% secure lock.
  • Inspect the Spring: Ensure the internal metal spring is not rusted or collapsed. If the spring is weak, the new knob will stay "compressed," causing the line to feed uncontrollably.
  • Snap-Lock Check: Press the new knob firmly into the housing until you hear a distinct "click" on both sides. Give the knob a firm tug by hand to verify it is fully seated before starting the engine.
  • Manual Feed Test: With the engine off, press the knob in and pull the trimmer line manually to ensure the indexing mechanism is releasing the line smoothly.
  • Avoid "Riding" the Head: To maximize the life of your new knobs, try to avoid letting the trimmer head drag on the ground while trimming; only make contact with the surface when you need to advance the line.
Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
  1. Standard Shipping : 3-10 business days
  • If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
  • We offer a 30-day return/exchange service after receiving.
  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
  • Please click here for more details>>> Return & Exchange Policy
SKU: 32455411855

Discover Niche Categories That Outsell

Top-Converting Item to Boost Your Average Order

4.4 ★★★★★
Based on 972 reviews
Sort
Highest Rating
Newest First
Oldest First
Product Reviews
C
Verified Purchase
crf
Natrona Heights, US
★★★★★ 3
Beautiful toy.
Color: Blue
I bought three. My pugs didnt like it. I gave 1 to neighbors dog(a terrier) lasted 3 days before tore apart. I gave my pugs toys to terrier. Liked it but came apart.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 18, 2026
A
Verified Purchase
Amazon Customer
Chelsea, US
★★★★★ 1
Not the least bit durable
Color: Blue
This is not durable! My pup had a hole in it in 5 minutes and a leg torn off in 3 days. He is not an aggressive chewer even....typically we have to replace toys because the squeaker has died, never because he tore it out!
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 5, 2026
J
Verified Purchase
Jeanette Duquaine
Birmingham, US
★★★★★ 5
FUN TO PICK UP IN HIS MOUTH
Color: Blue
mY LITTLE DOG ABSOLUTELY LOVES THIS TOY
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on March 4, 2026
K
Verified Purchase
KandiS1424
Omaha, US
★★★★★ 2
Adorable but not Durable
Color: Blue
While this toy was super adorable and our 1 year old puppy loved it. The colors were bright and vivid, and it made fun wrinkling sounds he absolutely loved. However we were lucky if it lasted 20 minutes. Within minutes the crinkle paper was coming out and it basically fell apart, and he's not a destructive pup.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on February 13, 2026
M
Verified Purchase
Maureen
Whiting, US
★★★★★ 5
Softness
Color: Pink
The pups love it. It’s soft and squishy and crinkly. Pretty colors too.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on February 21, 2026

recommand products