What This Drum Is and Where It Goes
This is a standard 16.5 x 7 drum with 10 bolt holes, balanced at the factory so you're not chasing a wheel vibration six months down the road. Most of these land on front or rear axle positions depending on the truck's brake spec — 16.5 x 7 is common on tandem rear axles for tractors and some straight truck front ends.
Balanced drums matter more than guys give them credit for. An unbalanced drum on a truck doing 65 mph down I-5 will shake your steering wheel or beat up your cab mounts over time. This one's already balanced, so you're not paying a shop extra to true it up.
How the Cross Numbers Line Up — and What to Double-Check
ConMet, Gunite, Webb, Meritor, Mack, Freightliner, Peterbilt, Paccar — they all build to the same 16.5x7, 10-bolt spec, which is why the numbers cross. Same bolt circle, same drum diameter and width, same balance spec. Gunite's 3600A and Webb's 66864B family show up because those companies have supplied this exact drum to multiple OEs for decades under private label deals.
Where guys get burned is assuming every 16.5x7 drum bolts on without checking. Bolt hole diameter and pilot bore can vary slightly between brands even with the same nominal size, and some trucks run a different offset depending on brake chamber clearance. If your old drum number isn't in our list, don't guess — pull the number off the drum you're replacing or check your axle tag against the VIN before you order.
This is a drum, not a hub assembly, so it doesn't touch seal size or spline count — that's your hub's business. But if you're replacing drum and hub together, make sure the hub bolt pattern matches this 10-hole spec too.
Ordering From PartStop
We're in Tacoma and keep these in stock for same-day will-call if you're local — walk in, match the old drum, walk out. Ship nationwide too if you're not near us, usually next-day or two-day depending on where you're at.
Comes with our standard 6+ month warranty. If it's wrong for your application we'll sort it out, but confirm fitment by your VIN or the number stamped on the drum you're pulling off before it ships — saves everybody a return shipping headache.
3600AX Cross-Reference & Interchange Numbers
These manufacturer and aftermarket numbers commonly cross-reference to 3600AX. 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 |
|---|---|
| ConMet | 10001776, 10001778, 10009830, 10001800, 107150 |
| Freightliner | N42A1657VB |
| Gunite | 3600A, 3570AX |
| Mack | 3398-3922X |
| Industry Number | 1657B |
| Meritor | 85-123207-002 |
| Webb | 56864B, 66864, 66864B, 66874B |
| Paccar | 306613 |
| Peterbilt | 305449, 03-05449 |
| Aftermarket | 9456 3600AX, 2308709, 10037763, 13 123207 002, E9HZ 1126 A, F4HZ 1126 B, 3922X, 9006X, 2359002, 600084 |
| Alliance | N42A10009830, N42A1657B, N42A1657NB |
Frequently asked questions
Does 3600AX fit my Freightliner Cascadia?
Depends on the axle and brake spec on your specific truck — Freightliner used the N42A1657VB number which crosses to this drum, but confirm by checking your build sheet or the number cast into your old drum before ordering.
Is this the same as the ConMet 10001776?
They cross-reference to the same 16.5x7, 10-bolt balanced drum spec, so functionally yes, but always match the number off your old part or check by VIN since ConMet supplies this drum across several truck makes with slightly different part numbers for the same physical drum.
How do I know if I need the front or rear version of this drum?
This listing covers the 16.5x7 size which shows up in both positions on a lot of trucks — the drum itself doesn't care where it goes, but double check your brake chamber and shoe clearance specs for that axle position before you install.
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.