Frequently Asked Questions About Freightliner FLC112 Drive Axle Springs & Hangers

Will these springs and hangers fit my specific year FLC112, and are there differences between model years?

Drive axle springs and hangers for the FLC112 are generally compatible across all production years (1988-1999), but there are important variations based on your truck's configuration. The key factors are your axle weight rating (typically 20,000, 23,000, or 40,000 lbs for tandems) and whether you have a single or tandem axle setup. Always verify your specific axle model number and weight rating before ordering. Most FLC112s use either Hendrickson or Neway suspension systems, which require different spring specifications.

What's the difference between OEM and aftermarket springs, and how long should I expect them to last?

OEM springs are manufactured to exact Freightliner specifications and typically last 500,000-700,000 miles under normal highway use. Quality aftermarket springs from reputable manufacturers like Dayton Parts or Triangle Suspension offer comparable lifespan at 20-30% less cost. The main differences are in the steel grade and heat treatment process. Heavy-duty aftermarket springs often use shot-peened construction for added durability. For vocational trucks or severe service applications, expect 30-40% shorter lifespan regardless of brand.

Can I replace springs and hangers myself, or do I need special tools and equipment?

While spring replacement is possible for experienced mechanics, it requires specific equipment including heavy-duty jack stands rated for commercial vehicles, a 20-ton hydraulic jack, spring compressors, and proper torque wrenches for U-bolt installation (typically requiring 300-450 ft-lbs). The job typically takes 4-6 hours per axle. Critical safety note: springs are under extreme tension and improper handling can cause serious injury. Most customers opt for professional installation, which runs $400-600 per axle including alignment.

How do I know when my springs or hangers need replacement, and can I replace just one side?

Signs of worn springs include uneven ride height (measure from frame rail to ground), visible cracks in spring leaves, separated or shifted leaves, and excessive squeaking. Worn hangers show elongated bolt holes, cracks at stress points, or excessive play in the bushings. While you can technically replace one side, it's strongly recommended to replace springs in axle sets to maintain proper weight distribution and prevent premature wear. Mismatched springs can cause dog-tracking, uneven tire wear, and handling issues.

What spring capacity do I need, and can I upgrade to heavier springs for increased payload?

Your required spring capacity must match your axle rating - never exceed the axle manufacturer's weight specification. Stock FLC112 single drive axles typically use 20,000 or 23,000 lb spring sets, while tandems use 40,000 or 46,000 lb sets. Simply installing heavier springs won't safely increase payload capacity as you're still limited by axle, bearing, and brake ratings. For legal weight increases, you need DOT certification for the entire suspension system. Overloading springs leads to premature failure and potential DOT violations with fines starting at $1,000.