showingo Deck Idler Tension Spring 607616 & 604110 Deck Idler Spring Tensioner Anchor Replacement for Hustler Raptor SD SDX/FasTrak SD SDX/Dash Super S Replaces 122388, 604291 (1PC)

What It Is

This is an aftermarket deck idler tension spring (sold as a single piece) that maintains proper belt tension on Hustler zero-turn mower decks. It replaces OEM part numbers 122388 and 604291, and fits models including Raptor SD, SDX, FasTrak SD, SDX, Dash, and Super S.

Fitment & Compatibility

Before buying, confirm your mower uses either the 607616 or 604110 spring design. Measure the spring’s free length (typically ~3.5–4 inches) and hook-to-hook distance to match your existing spring. This part fits most 48-inch, 54-inch, and 60-inch Hustler decks from the Raptor/FasTrak/Dash/Super S families, but check your deck’s idler arm and anchor point design. It is not a direct fit for Hustler’s commercial “Z” series or older models without the listed OEM numbers. The spring is aftermarket, not OEM, so verify your original part number matches 122388 or 604291 before ordering.

Key Things to Know

• Quality: Users report it’s a solid match to OEM springs at a lower price; no premature sagging or rust in normal use.
• Installation: Moderate difficulty—requires a spring puller or pliers to hook onto the idler arm and anchor. Watch for sharp edges.
• Gotcha: This is a single spring. If your deck uses two tension springs (some 60-inch decks), you’ll need to order two.
• Fit note: On some decks, the spring may require slight bending of the hook or anchor tab for a snug fit. Test tension before running the mower.

Should You Buy It

If you need a replacement idler spring for a Hustler Raptor SD/SDX, FasTrak SD/SDX, Dash, or Super S and your original part is 122388 or 604291, this is a cost-effective, well-reviewed option. It’s ideal for DIY repairs where OEM parts are overpriced or out of stock, but skip it if you want an exact OEM match or have a non-Hustler deck.