Trailer Spring Seats Frame Replacement.  Ensure your trailer is ready for the road with our top-of-the-line Trailer Spring Seats Frame Replacement . Designed to be a perfect fit for 2000 lb, 1 3/4 diameter axles, these weld-on spring seats are indispensable for modifying Carry-on utility trailers or adjusting the Harbor Freight model #94564 4x8 frame round axles. Crafted for reliability and ease of installation, the Trailer Spring Seats are available exclusively at Compact Camping Concepts and the Trailer Spring Seats are Sold as Pairs to meet all your camping and trailering needs.