10 Best Brake Slack Adjusters 2025

Looking for the best brake slack adjusters in the market? Look no further than our top 10 list of heavy-duty brake parts! We reviewed and scored many products in the brake slack adjusters category and found products ranging from a 7 score up to a 9.8 score. But there was one brand that stood out among the rest, and that's World American. Their AUTO SLACK ADJUSTER - 5.5" 28 SPLINE - REPLACES MERITOR R801073 received our highest rating with a score of 9.8! Trust us, this is the brake slack adjuster you've been looking for. Keep reading to find out why World American's product is the best on the market and which other products made the cut in our top 10 list.