What This Clamp Does
The air transfer tube carries charge air across the engine to the intake side. That joint runs hot, vibrates constantly, and gets heat-cycled every shift. The clamp is what keeps the connection sealed. When it loses tension, boost bleeds off at the joint and the engine goes soft under load, often with a whistle or chuff you can hear from the cab at full throttle.
This is a T-bolt design, not a worm-gear band. The T-bolt pulls the band evenly around the full circumference instead of bunching the material at a screw housing. That matters on a 2-7/8 inch (73 mm) connection carrying pressurized charge air, where uneven clamping load lets one side of the joint lift and leak while the gauge still shows the bolt is tight.
The band is stainless steel to handle the corrosion and high-heat service around the transfer tube. Underhood salt spray, road chemical, and repeated heat cycles are what kill the original hardware. Rust pitting at the band edge or a stretched bolt is a replace-now condition, not a re-torque condition.
Why These Numbers Cross
3040793 is the base reference number for this clamp on the Cummins 855 and N14 platform. Interstate-McBee lists it as M-3040793 and Powerline Components lists it as PC-3040793. Both suppliers use a prefix-plus-base convention: the letters identify the cataloging brand, and the digits after the prefix are the same 3040793 root.
Because the digits are identical, all three numbers point at the same physical piece of hardware — a 2-7/8 inch stainless T-bolt clamp for the air transfer tube joint. There is no dimensional split hiding behind the prefix. If your old clamp carries any of the three numbers, or you pulled the number off a parts list that shows one of them, you are looking at the same clamp.
Those numbers are listed here for identification only. PartStop is not affiliated with, endorsed by, or authorized by any OEM. A number match is a starting point, not a fitment guarantee — confirm against your engine serial number or the number stamped on the clamp you are removing.
Check Before You Order
Pull the old clamp and measure the tube outside diameter at the joint. This part is sized for the 2-7/8 inch (73 mm) connection. Big-cam 855 and N14 engines saw a long production run and plenty of rebuild history, so a previous repair may have left a different clamp or a non-standard tube on the engine. Measure, do not assume.
Get your engine serial number off the dataplate and verify before ordering. Application is Cummins 855 (NT855 / Big Cam) and N14 in Class-8 trucks including Kenworth W900 and T800 and Volvo VNL. If the truck has been repowered or the transfer tube replaced with something off-catalog, the chassis year tells you nothing useful — the engine serial does.
3040793 Cross-Reference & Interchange Numbers
These manufacturer and aftermarket numbers commonly cross-reference to 3040793. 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 |
|---|---|
| Interstate-McBee | M-3040793 |
| Powerline Components | PC-3040793 |
Frequently asked questions
Is M-3040793 the same clamp as 3040793?
Yes. M-3040793 is the Interstate-McBee catalog listing for the same 2-7/8 inch T-bolt air transfer tube clamp, with the prefix identifying the brand and the digits matching the 3040793 base number. PC-3040793 from Powerline Components follows the same pattern. Confirm against the number on the clamp you are pulling off.
How do I know the transfer tube clamp is what's leaking?
Look for soot streaking or a clean, oil-washed stripe at the joint where charge air is escaping past the seal. Under load you may hear a whistle or chuff and see reduced boost. Before replacing, check the band for rust pitting, a stretched or seized T-bolt, and any deformation in the tube itself — a damaged tube will leak with new hardware installed.
Can I reuse the original T-bolt clamp after removing it?
Not recommended if it has been in service through heat cycles. T-bolts stretch and stainless bands work-harden and pit, so a reused clamp often will not hold tension on a joint that already leaked once. Replace the hardware while the tube is off — it is far cheaper than chasing the same boost leak a second time.
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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
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