What You're Actually Buying
This is a 16.5" brake drum, cast for heavy duty service on International trucks - we're talking 1988 through 2024 depending on axle and configuration. It's not a light truck part, so don't get it mixed up with anything under 16" - that's a different drum family entirely.
International kept this basic drum spec around for decades because it works with a common S-cam foundation brake setup. That's why you see the same casting cross-referenced under International's own 66864B along with Webb, Meritor, and Alliance part numbers - they're all making a drum to the same mounting bolt pattern and swept diameter.
3922X, 89996B, 1516726BA, 85123207002 - these are all supersession numbers or aftermarket casting numbers for the same physical drum. Doesn't matter which one is stamped on your old part, if it's on this list, you're in the right family.
Where People Get Tripped Up
16.5" refers to the drum diameter, but that alone doesn't guarantee fitment. You've got different bolt circles, pilot bore sizes, and stud counts depending on axle manufacturer and GVWR rating. A drum that's 16.5" for a Meritor axle isn't automatically the same bolt pattern as one for a Rockwell or Dana axle.
The reason 85123207002 and 85123788002 both show up here as crosses - Meritor uses those numbers for drums built to fit their own axle spindles, and this casting matches that same mounting spec. Same story with the Webb numbers (56864B, 56846B) - Webb built to the same pattern for their own axle line.
Bottom line: match by the number stamped on your old drum, not by eyeballing the diameter. If the numbers on your worn-out drum aren't on this list, don't force it - pull your VIN or call us with the axle tag info and we'll verify before you order.
Buying This From Us
We stock 3922X in Tacoma and it typically ships same-day if you're ordering before early afternoon. Local fleets pop in and grab it off the shelf; everybody else, we ship nationwide and it usually lands in a couple days depending on where you're at.
Comes with our standard 6+ month warranty. It's a direct replacement for the numbers listed, but we still want you confirming against your old part or VIN before it goes on the truck - saves everybody a return shipment.
Call the counter if you're not sure. We'd rather spend five minutes checking than have you install the wrong drum and eat labor twice.
66864B Cross-Reference & Interchange Numbers
These manufacturer and aftermarket numbers commonly cross-reference to 66864B. 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 | 3922X, 89996B |
| Webb | 56864B, 56846B |
| Meritor | 85123788002 |
| Alliance | N42A1657NB, N42A1657B |
| Aftermarket | 85123207002, 10001776, 10009830, 10037763, E9HZ 1126 A, F4HZ 1126 B, 3401, 3600A, 3600AX, 9006X |
Frequently asked questions
Does 66864B fit my 2015 International ProStar?
Likely yes, since ProStar runs the same 16.5" drum family, but axle configuration varies by trim and GVWR. Give us your VIN and we'll confirm before you order - takes two minutes on our end.
Is this the same as the Meritor 85123207002?
It interchanges with it - meaning it's built to the same mounting spec and swept diameter for Meritor axle applications. Not the same brand-name part, but functionally it crosses over. Confirm the number on your old drum matches before swapping.
Why are there so many different numbers for one drum?
Supersessions and multiple manufacturers building to the same casting spec is why. International, Webb, Meritor, and the aftermarket brands all have their own part numbers for what amounts to the same drum. That's normal in this business - just match off the old part number, not the diameter alone.
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.