ISX15 / X15 EGR Exhaust Manifold Hardware & Gasket Kit | Stud & Nut (Performance Upgrade)
The Diesel Power Source® ISX15 / X15 EGR Manifold Hardware & Gasket Kit (Stud & Nut) is the long-haul-grade install package for the DPS Stock Replacement ISX15 / X15 Exhaust Manifold on EGR-equipped Cummins ISX15 and X15 engines. The fastener configuration is the meaningful change: every manifold-to-head bolt position becomes a stud with a serrated flange nut, which is the configuration that holds up best on trucks accumulating hundreds of thousands of miles between manifold removals.
This is the performance stud-and-nut upgrade over the OEM-style configuration - purpose-built for the heat-cycle counts and load profile of long-haul over-the-road work. If you'd rather match Cummins production-line spec for warranty work or fleet PM, the Bolt & Spacer kit covers that workflow.
Pairs with the DPS Stock Replacement ISX15 / X15 EGR Exhaust Manifold (MAN1004 / MAN1008). Kit contents cover the manifold-to-head studs and serrated nuts, the multi-section gasket set, the EGR gasket, the turbo flange gasket, and the turbo flange hardware — the full fastener and gasket scope of an ISX15 EGR manifold replacement, configured for long service life.
Why High-Mileage EGR Trucks Benefit From Studs
An ISX15 in OTR fleet service runs through more thermal cycles in a year than most pickups see in a decade. Each warm-up and cool-down loads and unloads the manifold-mounting fasteners as the cast iron expands and contracts. Bolt threads in cylinder heads accumulate galling and corrosion across that mileage, and EGR-equipped engines run hotter at the manifold than non-EGR equivalents because exhaust gas re-enters the system instead of clearing out the tailpipe. The combination is exactly the load profile that wears bolts out faster than studs.
Stud-and-Nut Mounting Holds Pre-Load Better
A stud carries clamping load through its full unsupported length, with the nut tightening against the flange face. Bolts apply load through threaded engagement in the head, where corrosion and thread fatigue erode pre-load over time. Across a million miles of OTR service, the difference shows up as fewer manifold leaks at the gasket — and a head with intact bolt threads when the manifold finally does come off.
Serrated Flange Nuts
Every nut in the kit is a serrated flange nut. The serrated under-face bites into the manifold flange and resists vibration loosening — important on a Class 8 truck where the manifold sees engine vibration plus chassis input over highway expansion joints, hour after hour, day after day.
Easier Removal at PM Intervals
When the manifold does need to come off — for a head job, an EGR cooler service, or a turbo replacement — backing nuts off studs is significantly faster than fighting bolts whose threads have spent years cycling between 1000°F and ambient. Saved labor compounds across every R&R event for the life of the truck.
Who This Kit Is For
- Owner-operators and fleet maintenance shops servicing EGR-equipped Cummins ISX15 and X15 engines
- Class 8 trucks — Kenworth, Peterbilt, Freightliner, Mack, Volvo, International, Western Star
- Long-haul over-the-road trucks accumulating high mileage between service intervals
- Vocational and high-load applications putting extra thermal stress on manifold hardware
- Shops and fleets that want stud-mount durability for easier future service work
- Builders who want all install hardware and gaskets in a single SKU
What's Included
| Qty | Component | Purpose |
|---|---|---|
| 1 | ISX EGR Gasket | Seals EGR connection to manifold |
| 1 | ISX Non-Divided Turbo Flange Gasket | Seals turbo to manifold flange |
| 1 | Turbo Oil Drain Gasket | Seals oil drain line to turbo |
| 1 | ISX Manifold Center Gasket | Seals center manifold section to head |
| 4 | ISX Manifold End Gaskets | Seals end manifold sections to head |
| 4 | M10-1.5 × 20-12-16 Turbo Studs | Mounts turbo to manifold flange |
| 4 | M10-1.5 Turbo Flange Nuts | Pairs with turbo studs |
| 12 | M10-1.5 × 20-20-16 Manifold Studs | Manifold-to-head mounting |
| 12 | M10-1.5 Serrated Flange Nuts | Pairs with manifold studs |
Key Features
- Performance stud-and-nut manifold mounting — replaces OEM-style flange bolts
- Serrated flange nuts — resist vibration loosening on heavy-duty applications
- EGR gasket included — covers EGR-equipped emissions-intact ISX15 and X15 trucks
- Multi-section gasket set — center plus end gaskets sized for the DPS multi-piece manifold
- Direct fit for the DPS Stock Replacement ISX15 / X15 EGR Manifold
- Single-source convenience — every gasket and fastener in one SKU
Benefits
- Reduces manifold-bolt loosening and fastener fatigue from repeated heat cycling — critical for long-haul service
- Improves long-term sealing across all manifold-to-head sections and turbo flange
- Makes future manifold removal easier — back off nuts instead of fighting seized bolts
- Eliminates the need to source manifold gaskets, EGR gaskets, turbo studs, and mounting hardware from multiple suppliers
- Reduces shop time per manifold replacement — every part needed is in one box
Fitment
- Cummins ISX15 and X15 EGR-equipped engines
- Pairs with the Diesel Power Source® Stock Replacement ISX15 / X15 EGR Exhaust Manifold (MAN1004 / MAN1008)
- Class 8 commercial trucks — Kenworth, Peterbilt, Freightliner, Mack, Volvo, International, Western Star
- Fits all DPS multi-section ISX15 / X15 EGR manifolds with the factory-style turbo flange
Note: This kit is for the EGR-equipped ISX15 / X15 stock-replacement manifold. If your engine is non-EGR equipped, see the ISX15 / X15 Non-EGR Manifold Hardware Kit. If you're running the DPS T6 performance manifold for S400 frame turbos, see the T6 hardware kit instead.
Pairs With This Kit
Frequently Asked Questions
For long-haul OTR work, yes — the load profile is exactly what stud mounting is designed for. An ISX15 in fleet service runs through an order of magnitude more thermal cycles per year than typical truck applications, and stud pre-load holds up under that cycle count better than bolts that thread directly into the head. The labor savings on future R&R alone often justify the upgrade across a single-truck lifetime.
Yes. The studs thread into the same M10 head bores the factory bolts use. No machining, drilling, or tapping required. Installation is essentially identical to the bolt configuration except that you tighten nuts onto studs rather than driving long bolts.
The spec is a metric serrated flange nut — the serrations on the under-face bite into the manifold flange and resist vibration loosening. On a Class 8 truck running hour after hour at highway speed, the combination of engine vibration and chassis input cycles through plain nuts faster than people expect. These nuts hold torque significantly longer between re-checks.
It includes the EGR-to-manifold gasket. The EGR cooler itself reuses its existing mounting hardware in most service work, so additional EGR fasteners aren't part of the kit. If your EGR cooler hardware is corroded or damaged, source replacements separately before reassembly.
