- On order
ACL trimetal connecting rod bearings Nissan TB42 TB45 TB48DE
Set of 12 trimetal connecting rod half-bearings for Nissan inline six TB42, TB45 and TB48DE.
- Brand and treatment: ACL Race
- Compatibility: Patrol GR Y60, Patrol GR Y61, Patrol Y62, Patrol III
- Engine codes: TB42, TB45, TB48DE
- Available sizes: standard to +0.25 mm, increased-clearance version (HX)
The Nissan TB42, TB45 and TB48DE six-cylinder engines
The TB42 is the 4.2-litre inline six of the Nissan Patrol, with a side camshaft and 12 valves; the TB45 takes it to 4.5 litres, and the TB48DE to 4.8 litres with double overhead camshafts and 24 valves. ACL lists the same bearing set for these three engines: a single set covers the family.
From the factory, this engine is fitted with standard production connecting rod bearings, sized for the loads of the original engine: as soon as power, engine speed or boost pressure increase, they reach their limits.
From the factory, Nissan fits these engines with connecting rod bearings under part number 12111-03J00, and its workshop manual specifies a running clearance of 0.027 to 0.061 mm.
Trimetal connecting rod bearings
In a trimetal bearing, a steel back carries a copper-lead intermediate layer with high load capacity, itself covered by an anti-friction running layer that spares the crankpin. The set is supplied complete: 12 half shells, i.e. 6 pairs.
Trimetal targets high, sustained loads, whereas aluminium bi-metal is limited to low to medium loads: about 8,000 psi for the latter, up to 12,000 psi for a performance trimetal, 50% more. The benefit shows in strength and durability on turbo, supercharged and high-revving engines.
Technical specifications
| ACL bearings Crankpin Ø 56.913 / 56.926 mm Housing bore Ø 59.987 / 60.000 mm Width 26.1 mm |
| Reference | Brand and treatment | Size | Wall thickness (mm) |
|---|---|---|---|
| 6B2955H-STD | ACL Race - Untreated | Standard | 1.512 |
| 6B2955HX-STD | ACL Race - Untreated | Std, increased clearance (HX) | 1.499 |
| 6B2955H-.025 | ACL Race - Untreated | +0.025 | 1.525 |
| 6B2955H-.25 | ACL Race - Untreated | +0.25 | 1.637 |
Running clearance
Running clearance is the gap between the bearing and the crankpin, filled by the oil film.
While the engine turns, the crankpin floats on this oil film, which carries the load without direct contact with the bearing. Film thickness depends on clearance: too tight, oil passes poorly, temperature rises and the risk of seizure grows; too wide, oil escapes, the film carries less and oil pressure decreases. A correct clearance ensures both sufficient lubrication and a well-maintained film.
| Size / grade | When to choose it | ACL Race Series |
|---|---|---|
| Standard (STD) | Standard journal, not reground | 0.059 to 0.070 mm |
| Increased clearance (HX) | Wider clearance: high oil flow, high rpm | 0.084 to 0.095 mm |
| +0.025 mm | Polished journal | 0.059 to 0.070 mm |
| +0.25 mm | Journal reground to 0.25 mm | 0.059 to 0.070 mm |
Checking on assembly: lay a calibrated strip (Plastigauge) on the journal, torque the rod cap to spec, then compare the crushed strip against the gauge to read the clearance.
Technical guide
These ACL trimetal connecting rod bearings are aimed at built engines and racing: where a standard bearing quickly reaches its limit, they accept more power, more rpm and more boost. The range includes the standard size, a +0.025 mm size for a crankpin that has only been polished, a +0.25 mm regrind size and the HX version with increased clearance for high-revving engines or engines needing a high oil flow. It allows the same part number to be kept after the crankshaft is reground and the clearance to be tailored to the oil used and the engine's duty.
The brand
 |
An Australian specialist in high-performance engine bearings since 1949, ACL Bearing Company produces the Race Series: precisely made trimetal bearings, available in numerous sizes and recognised on built engines across the world. |
Vehicle compatibility
This connecting rod bearing set fits the TB42, TB45 and TB48DE six-cylinder engines of the following Nissan models:
| Brand | Model (chassis) | Engine code | Power | Years |
|---|---|---|---|---|
| NISSAN | PATROL GR IV (Y60, GR) 4.2 Cat / 4.2 Efi 4WD (CGY60, WGY60) | TB42E | 165–175 hp | 1988–1998 |
| NISSAN | PATROL GR V Pickup (Y61) 4.8 4WD | TB48DE | 248–284 hp | since 2014 |
| NISSAN | PATROL GR V Wagon (Y61) 4.2 | TB42E | 170 hp | 2000–2002 |
| NISSAN | PATROL GR V Wagon (Y61) 4.2 | TB42S | 170 hp | 2000–2002 |
| NISSAN | PATROL GR V Wagon (Y61) 4.5 i / 4.5 (Y61) | TB45E | 197–200 hp | since 1997 |
| NISSAN | PATROL GR V Wagon (Y61) 4.8 / 4.8 (Y61) | TB48DE | 245–280 hp | since 2000 |
| NISSAN | PATROL III/1 Platform/Chassis (MQ, MK, GQ) 4.2 Carb (Y60) / 4.2 4x4 (G160) | TB42 | 116–170 hp | 1980–1997 |
| NISSAN | PATROL III/2 Hardtop (K260) 4.2 | TB42E | 170–175 hp | 1988–1997 |
| NISSAN | PATROL VI (Y62) 4.8 | TB48DE | 280 hp | since 2013 |
Why replace the bearings
Replacing the bearings during a build or rebuild guards against the most expensive failure: a worn-out connecting rod bearing scores the crankpin, contaminates the oil circuit with debris and forces at least a crankshaft regrind, or even a new rod and block. Against such costs a new set weighs little: it is the cheapest part of the rotating assembly, but the one whose failure costs the most.
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Brand
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Reference6B2955H-STD
