What This Flex Pipe Is and Where It Lives
A flex bellows like the A04-30008-000 sits in the exhaust piping to absorb engine movement and thermal expansion so the rigid pipe sections downstream don't crack from vibration. On most setups it's between the turbo or manifold outlet and the vertical stack or muffler inlet, and it's usually the first thing to fail because it's flexing every time the engine rocks on its mounts.
This one's a 5-inch ID bellows, listed as a universal-fit piece, meaning it's not tied to one specific chassis - it's sized to match pipe diameter, not a particular truck model. That's common with flex sections since the same 5-inch stainless bellows shows up across Freightliner, Kenworth, Peterbilt, and International builds depending on what exhaust shop or OE supplier built the system.
Because it's universal, the real fitment check isn't the truck badge on the hood - it's measuring your old pipe's ID and overall bellows length before you order.
How the Cross-Reference Numbers Line Up
The Automann and Dinex numbers listed cross to this part because they're all manufacturing the same 5-inch flex bellows design to the same industry-standard dimensions - same ID, similar overall length, same style of end prep for welding or clamping in. That's why PN-3-B-036, 430008000, and the Automann/Dinex numbers all reference the same physical part even though the box art says different brands.
Where you can get burned on flex pipe is length and end style - some come with a straight cut end for welding, others have a slight flare or bead for clamp-on install. If your old pipe was welded in and you order a clamp-style replacement, you're stuck cutting and re-welding anyway, so it pays to check that before it ships.
Surest way to confirm is measure the old bellows - ID, overall length including any straight tube sections on each end - and match that against the spec sheet, not just the brand name on the old part.
Ordering From PartStop
We keep this one in stock in Tacoma for same-day will-call, and we ship it out the same day nationwide if you're ordering for a shop somewhere else. At $459 it's not a cheap patch job, so we'd rather you get the right one the first time than eat a return shipping charge on a heavy piece of stainless.
Give us your VIN or the number stamped on the old flex pipe and we'll run it against our cross-reference before you buy, not after. Comes with our standard 6+ month warranty, and if something's off on fitment we'll sort it - just don't cut it to length before you call us.
A04-30008-000 Cross-Reference & Interchange Numbers
These manufacturer and aftermarket numbers commonly cross-reference to A04-30008-000. 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 | PN-3-B-036, 430008000 |
| Automann | 820.B46308P, 03-08040005 |
| Dinex | 3FA013, 3FE010 |
Frequently asked questions
Does A04-30008-000 fit my Kenworth T680?
Possibly - it's a universal 5-inch flex bellows, not built exclusively for one chassis, so fit depends on your specific exhaust routing and pipe diameter. Measure your old flex section's ID and length, or give us the number off it, and we'll confirm before you order.
Is this the same as the Dinex 3FA013?
They cross-reference to each other because both are 5-inch stainless flex bellows built to the same industry dimensions, but Dinex packaging and end-finish can differ slightly from ours. Compare the ID, overall length, and end style side by side or call us with the numbers off both and we'll tell you straight if they're interchangeable for your application.
How do I know if I need the welded or clamped version?
Look at how your current flex pipe connects on both ends - if there's a clamp band around a straight pipe section, you need the clamp-style; if it's welded solid to the manifold or downpipe, you need a straight-cut end for welding. Pull the old part and check both ends before ordering, since flex pipes don't universally interchange between the two styles.
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.