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%

Pay in installments of $3.76 with ShopPay, AfterPay and Klarna

Shipping Estimate
USA
  • USA
  • CAN

Ships within 48 hours · Estimated delivery Aug 2 - Aug 7

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

4.9 ★★★★★
Based on 6 reviews
Sort
Highest Rating
Newest First
Oldest First
Product Reviews
N
Verified Purchase
Nolan F. Baby
Phoenix, US
★★★★★ 5
Grille-ing Me Softly: A 30-Minute Makeover Adventure
Color: Single Slat Gloss Black, Size: 2019-2022 G20, Color: Single Slat Gloss Black, Size: 2019-2022 G20
Installing this grille was a breeze! It took me about 30 minutes, even with a minor hiccup of having to uninstall it to add the front camera panel I initially forgot. The grille feels incredibly durable, made from plastic that matches the quality of the OEM version. Plus, it gives my car a fresh, youthful look. Highly recommend for a quick and stylish upgrade!
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 29, 2025
G
Verified Purchase
GKRetired
Lake Worth, US
★★★★★ 5
Good quality
The material is very sturdy and came rolled up. Left it on the kitchen counter for a week with weight on it to get it close to flat. When installing there are about 3 predrilled holes in the mat. You have to drill into the floor board to install provided clips which is fine, but I had extra clips so I drilled additional holes in both sides to get the malt flush. I like the mats.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on March 3, 2026
M
Verified Purchase
Mike M.
Port Orchard, US
★★★★★ 5
A plus
I am extremely happy with these mats. Perfect fit and well made at a good price.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on March 3, 2026
P
Paul Pryor
Alexandria, US
★★★★★ 4
Fit perfectly!
The only complaint was they are shipped rolled up. Have to let them set out in the sun all day to flatten out. They're not rubber! More like a WeatherTech floor mats in a vehicle. Had plastic rivets to mount them to the floor, but wasn't drilling holes in a brand new buggy......
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 9, 2023
V
Verified Purchase
victor gonzalez
Alexandria, US
★★★★★ 5
Fits like a glove
Style: Gloss Black Single Slat, Size: G20(2019-2022), Style: Gloss Black Single Slat, Size: G20(2019-2022)
I was kind of skeptical to purchase this grille but ended up pulling the trigger on it , installation was not that hard, the hardest part is to swap the camera attachment to the non camera one , after that everything was a breeze, looks great and the material quality is no different from oem, will do another review after couple of months to give more info on the durability and paint fading ( if there’s any, hope not)
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on December 27, 2024

recommand products