Parts For Detroit Diesel Series 60 12.7 Ltrs - Camshaft Section

Camshaft Parts for Detroit Diesel Series 60 12.7L — What’s Included & How They Work Together

A healthy Detroit Diesel Series 60 12.7L valvetrain depends on more than the camshaft alone. The cam rides on cam bearings, is located axially by a thrust plate and thrust seal, drives the valves and injectors through rocker arms with roller-and-pin assemblies, and is timed to the crankshaft through the front gear train (bull gear, cam gear, and idler with its bearing). Up front, cover gaskets and shaft seals keep the oil in and the mess out. Here’s how each piece fits into the system and when to replace it:

Camshafts (12.7L)

The overhead cam controls intake, exhaust, and injector events. On the 12.7L, you’ll see configurations aligned to DDEC III or DDEC IV, and two common cam-gear fastener interfaces (18 mm or 20 mm cam bolt). Match the cam to your engine build and bolt size. Replace the cam when you observe lobe pitting/flat-spotting, blueing from heat, measurable lobe loss, or persistent top-end noise after correct lash and injector height settings.

Pro move: If the cam needs replacement, plan to do bearings, thrust components, and rollers/pins at the same time to protect the new lobe surfaces.

Cam Bearings

These support the cam journals and regulate oil clearance to the cam and rockers. Excess clearance reduces top-end oil pressure and accelerates wear. Replace bearings whenever the cam is out on a high-mile engine, when journal clearance is beyond spec, or if you see scoring. Align oil holes correctly and verify oil flow during priming.

Thrust Control (Thrust Seal & Thrust Plate Seal)

The camshaft must have controlled end-play. The thrust seal and thrust plate seal prevent oil leaks and keep axial motion within spec. Replace them during any cam or front gear service. After installation, re-measure end-play and ensure the cam spins freely by hand.

Rocker Arm Roller & Pin Kits (Injector/Exhaust & Intake)

Roller followers ride the cam lobes and must rotate smoothly. Worn rollers or loose pins turn rolling contact into sliding contact—fast-tracking lobe damage. On the Series 60 12.7L, you’ll typically replace twelve injector/exhaust rollers and pins and six intake rollers and pins as sets. Look for ticking after a proper lash set, roughness while hand-rotating the engine, or needle slop when the rocker is off the shaft.

Camshaft Woodruff Key

A small part with big consequences. The key ensures precise phasing between cam and gear. Any burrs, shaving, or wear can allow timing drift. Always install a fresh, correctly sized key during cam or gear work and inspect the keyway for damage.

Gear Train (Bull Gear & Idler Gear Bearing)

The crank drives the bull gear, which drives the cam gear through an idler gear. Worn teeth or a failing idler bearing can cause gear whine, timing jitter, and accelerated wear on the cam gear. Replace suspect gears as a matched set when possible and renew the idler bearing if there’s measurable play. After assembly, verify backlash and check tooth contact pattern.

Accessory Drive Cover Gasket & Oil Seal

These front-end sealing components prevent oil leaks that contaminate belts and pulleys. Replace them if you have the cover off for cam or gear work, or any time you see oil mist at the front of the engine. Confirm cover flatness and shaft surface finish before reassembly.

When to Service the Whole Camshaft System

• Top-end tick or haze that persists after a proper lash/injector set.
  
  

• Metal in oil (filter media inspection or magnetic plug debris).
  
  

• Gear whine that scales with RPM.
  
  

• Front cover oil leaks or oil on belts.
  
  

• Measured end-play or journal clearances out of spec.
  
  

If one component is worn, the others often aren’t far behind. Servicing the camshaft system as a package—cam, bearings, thrust components, roller/pin kits, key, critical gear-train pieces, and fresh seals—reduces downtime and protects your investment.

Quick Selection Map 

Accessory Drive Cover Gasket → reseal the front case during cam/gear work

1. Rebuilt Camshaft (DDEC III) → for DDEC III 12.7L builds
   
   

2. Rebuilt Camshaft (18 mm Bolt) → verify your cam bolt diameter
   
   

3. Rebuilt Camshaft (20 mm Bolt) → for later 12.7L using 20 mm interface
   
   

4. Cam Bearings → restore oil clearances and support
   
   

5. Roller & Pin Kits (Injector/Exhaust) → replace all 12 together
   
   

6. Roller & Pin Kits (Intake) → replace all 6 together
   
   

7. Camshaft Thrust Seal → control axial motion and seal oil
   
   

8. Thrust Plate Seal → companion seal at the cam nose
   
   

9. Woodruff Key → lock in precise cam phasing
   
   

10. Bull Gear Set → renew primary gear drive (check DDEC generation)
    
    

11. Idler Gear Bearing → stabilize gear mesh and reduce whine
    
    

12. Accessory Drive Oil Seal → keep belts dry and leak-free

Why Buy Your Series 60 12.7L Camshaft Parts from Diesel Pro Power

Built for pros, trusted by fleets. With 40,000+ satisfied customers, Diesel Pro Power pairs high-quality components with real-world expertise so your Detroit Diesel Series 60 12.7L repair is right the first time.

• Correct fitment, guaranteed. Series 60 details matter—DDEC III vs. IV, 18 mm vs. 20 mm cam bolt, roller/pin counts, gear-train variations. Share your ESN and build info and we’ll confirm the exact cam, bearings, thrust components, rollers, keys, and gear-train parts you need—before you buy.
  
  

• Quality you can measure. Rebuilt camshafts are processed for straightness, hardness, and lobe geometry; companion parts (bearings, rollers, seals, gaskets) meet or exceed OEM spects with premium aftermarket parts to protect the new cam and stabilize timing.
  
  

• Everything in one cart. From bull gear sets and idler bearings to thrust seals, cover gaskets, and roller/pin kits (12 injector/exhaust + 6 intake), we stock the full system so you can service the cam and gear train in a single downtime window.
  
  

• Fast shipping, predictable turnaround. Parts ship quickly from stocked inventory so you can button up the front cover and get back on the road without waiting.
  
  
  

• Bilingual service & global reach. English/Spanish support and worldwide shipping keep mixed-language teams and international operations moving.
  
  

Bottom line: Diesel Pro Power gives you the right Series 60 12.7L camshaft parts, verified fitment, and hands-on support—so you can repair once, run clean, and extend top-end life.