yd25.com.au

 140 kw engine

Watch Our Install Video (being a 140kw make sure you check alignment between all sprockets in the bottom and install balance shaft delete)

 

The original euro 2 yd25 engine had a double row fuel pump chain. The euro 3 and euro 4 yd25 engine used a single row fuel pump chain but the guides and sprockets remained double row thickness. The euro 5 140kw engine still uses a single row chain but the sprockets were made thinner.

 

Because the sprockets are thinner on the 140kw model when you put a double row sprocket on the crank it pushes out the crank helical gear reducing the contact area between the balance shaft gears. Some parts suppliers have made a 1/2 thickness crankshaft helical gear to drive the balance shaft idler gear. Having 1/2 the gear meshing area than the original. This causes the idler gear to wear excessively. The shed metal contaminates the engine oil causing damage to the oil pump first then the rest of the engine. 

140kw single row chain balance shaft gear alignment		140kw with duplex chain fitted misaligned crank gear		140kw with duplex chain fitted misaligned crank gear

 

Due to the balance shaft gear misalignment, there are 2 options either don't run the balance shaft which Nissan does with all yd25 d22 Navaras, and single cab 2wd d40 Navara or maintain the balance shaft by make a thicker balance shaft idler gear to retain the full thickness of the balance shaft gears.

Balance shaft delete with a spacer in place of the crank helical gear	Balance shaft retained with billet helical gears

 

To convert to a double row the 140kw also needs a bigger tensioner guide bolt and a modified bottom tensioner.

Larger bolt to suit double row guide	Tensioner Modified to suit the thicker oil pump on the 140kw models

 

140 Kw engines come with 2 vacuum pumps. We cannot tell from the VIN which pump is fitted.  You need to identify which pump is fitted to your car. Below are the 2 pumps. The sprockets for each is different. It is imperative that sprocket chain alignment from the crank to vacuum pump is achieved. This is done by us making special shims. Check chain alignment from the vacuum pump sprocket to the fuel pump sprocket is a must for chain longevity. This is achieved with fuel pump shims.

Early vacuum pump		Late vacuum pump

 

Vacuum Pump Sprocket to suit early pump (left) Vacuum Pump Sprocket to suit Late pump (Right)