What You're Actually Buying
This is a full king pin kit for the Meritor MFS+ front axle — pins, composite bushings, thrust bearings, seals, and the hardware to put a knuckle back together on a double draw key axle. Double draw key means two keys locking the pin in the beam instead of one, which is how Meritor set up the MFS+ series to handle the load without the knuckle walking.
MFS+ axles showed up across a lot of Class 7-8 trucks — Freightliner, International, Kenworth, Peterbilt, Volvo, Mack — basically anybody who spec'd a Meritor front end from the factory. The composite bushing design replaced the old bronze bushing kits Meritor used earlier, mainly because composite doesn't need the same grease intervals and holds up better against dry-out and pin wear.
If your knuckle has visible play, or you're chasing a wander/shimmy complaint that isn't tires or alignment, worn king pins and bushings are usually the culprit. This kit fixes that on the MFS+ double draw key setup specifically — not the single key or the older bronze-bushing versions.
Why These Numbers Cross
R201609 is the Meritor number, and it's what the other brands are built to match — 8235-R201609, S537241010, K152184, 5012212R1, and TDAR201609 all reference back to this same kit spec. Different suppliers, same pin diameter, same bushing bore, same thrust bearing and seal package for the MFS+ double draw key axle.
Where guys get burned on kingpin kits is pin length and bushing ID — even a few thousandths off and you're fighting a knuckle that won't seat right or a pin that binds under load. Since these all cross to the same Meritor spec, that's less of a worry here, but it's still worth checking the double draw key detail specifically, because Meritor also ran a single key version that looks close on paper but isn't the same kit.
Bottom line — pull the number off your old kit or off the axle tag, or run the VIN, before you order. We'll confirm it against R201609 either way, but starting with the right number saves everybody a shipping hassle.
Ordering From PartStop
We keep R201609 in stock here in Tacoma — same-day pickup if you're local, and we ship nationwide if you're not. Front-end work isn't something you want sitting on backorder while a truck's down.
Comes with the standard 6+ month warranty. If something's off with the kit — wrong bushing fit, bad seal, whatever — call the counter and we'll sort it, no runaround.
One more thing worth saying: this is a kit for a rebuild, not a shortcut around a bent knuckle or worn beam bore. If the beam's oversized from wear, no kingpin kit is going to fix that — that's a machine shop or new beam conversation.
R201609 Cross-Reference & Interchange Numbers
These manufacturer and aftermarket numbers commonly cross-reference to R201609. Use them to identify the part — then confirm the exact fit by VIN or the number stamped on your old unit before you order. An interchange is a starting point, not a fitment guarantee.
| Brand / Line | Cross-Reference Numbers |
|---|---|
| Cross-Reference | 8235-R201609, S537241010, K152184, 5012212R1, TDAR201609 |
Frequently asked questions
Does R201609 fit my Freightliner Cascadia with a Meritor MFS+ front axle?
Likely yes if it's the double draw key style, but confirm by pulling the axle tag or matching against your old kit's part number before ordering. Meritor used a few different key configurations across MFS+ years, and we'd rather you check than eat a return shipment.
Is R201609 the same as the K152184 crossover number?
Same kit spec, different supplier part number — K152184 is built to the same pin/bushing/seal package as R201609. Confirm off your old kingpin's number or the axle tag either way, since we can't guarantee fit sight unseen.
Can I use this kit if my truck still has bronze king pin bushings?
No — this kit is composite bushings for the updated MFS+ design. If your knuckle currently runs bronze bushings, you need the bronze-specific kit, not this one. Check your old bushings before ordering.
Not sure it fits? We check before you pay.
Run your VIN and we’ll match parts to your exact truck, or call the counter — a person who knows trucks verifies fitment by OEM number before the order ships. No wrong-box returns.
More cross-reference guides
Need the part, not just the reading?
Every part below is a Premium Quality aftermarket Direct Replacement with published OEM cross-reference numbers, a 6+ month warranty and same-business-day shipping from Tacoma, WA. Not sure it fits? Run your VIN — or call and a person who knows trucks will verify fitment before you pay.