What This Drum Is and Where It Goes
This is a 16.5-inch diameter, 5-inch wide drum, outboard mounted, with a 10-hole bolt pattern. That size and mount style is common on tandem trailer axles and some medium-to-heavy truck applications running Meritor, Webb, or similar drum brake foundations.
3758X isn't tied to one truck brand — it's a drum size and mount spec that shows up across trailer builders and axle manufacturers. Doesn't matter if you're running a Great Dane, Wabash, Utility trailer, or a straight truck with the right axle — what matters is the drum diameter, width, hole count, and mount style all matching what's coming off your axle.
How the Cross Numbers Line Up
Gunite's 3598X, ConMet's 107453 and 10005332, Meritor's 123589, Webb's 65151B and 65151B20, Mack's 23915740 — these all cross to the same 16.5 x 5 outboard 10-hole spec as 3758X. Different foundries, different part numbers, same physical drum dimensions and bolt pattern.
Where guys get burned is assuming a cross-reference number is automatic. Drum diameter and width are usually spot-on across these crosses, but always double-check hole spacing and mount type before you bolt it up — outboard vs inboard mount will not interchange even if the diameter matches. If your old drum is worn past the wear indicator or cracked, measure what you can and check the casting numbers.
Rule of thumb: pull the number off your old drum, or run your VIN, and match it against this list before you order. A drum that's close but not exact will either not bolt up or won't seat right against the hub — neither is a good day on the side of the road.
Ordering From PartStop
We keep 3758X in stock in Tacoma, and if you're local we can usually have it ready same-day. Ship nationwide if you're not close enough to swing by — doesn't matter if you're a one-truck operation or running a yard full of trailers.
Every drum we sell carries our 6+ month warranty. Confirm the number off your old part or check your VIN before ordering — we're happy to help match it up if you're not sure, but the final call on fitment is verifying against what's actually on the truck or trailer.
3758X Cross-Reference & Interchange Numbers
These manufacturer and aftermarket numbers commonly cross-reference to 3758X. 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 |
|---|---|
| GUNITE | 3598X |
| CONMET | 107453, 10005332 |
| MERITOR | 123589 |
| WEBB | 65151B, 65151B20 |
| Mack | 23915740 |
| Replaces | 3398-3758, 3398-3758X |
Frequently asked questions
Does 3758X fit my trailer?
Likely, if your trailer axle uses a 16.5" x 5" outboard mount, 10-hole drum brake setup. Confirm by pulling the number off your old drum or checking your axle manufacturer's spec — don't just go by trailer brand alone, since axle suppliers vary.
Is this the same as the Meritor 123589?
They cross-reference to the same drum spec — 16.5" x 5", outboard, 10-hole. Meritor's part is their own casting number, but the dimensions and mount match up. Still worth checking your old drum's number against the cross-reference table before ordering.
What's the difference between 3758X and Webb 65151B20?
Physically, they're built to the same 16.5 x 5 outboard 10-hole spec, so they cross-reference. The '20' suffix on Webb's number sometimes denotes a running change or balance spec — if you're matching an exact OE part, check your old drum's full number and confirm against your parts manual or VIN before swapping.
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.