Review: Jeep WH.I Grand Cherokee (2005-08)

Overview

Released in July 2005, the Jeep WH Series I (WH.I) Grand Cherokee was a five-seat, 4WD wagon. Manufactured in Detroit, USA, the WH Grand Cherokee was available with five engines and in Laredo, Limited and SRT-8 variants (see table below).

Engines

Of the engines:

The 3.0-litre Mercedes-Benz OM642 turbo-diesel V6 engine had an aluminium block and cylinder heads, common rail injection, double overhead camshafts, a counter-rotating balance shaft, four valves per cylinder and a compression ratio of 18.0:1;
The 3.7-litre ‘PowerTech’ V6 petrol engine had a cast iron block and aluminium cylinder heads, single overhead camshafts, two valves per cylinder, a counter rotating balance shaft and a compression ratio of 9.6:1;
The 4.7-litre ‘PowerTech’ V8 petrol engine had a cast iron block, aluminium cylinder heads, chain-driven double overhead camshafts, two valves per cylinder and a compression ratio of 9.3:1;
The 5.7-litre ‘Hemi’ V8 petrol engine had a cast iron block, two valves per cylinder actuated by pushrods, hydraulic lifters with roller followers and a compression ratio of 9.5:1. The engine also featured a Multi-Displacement System (MDS) which could shut down half the cylinders when cruising or under light throttle inputs; and,
The 6.1-litre ‘Hemi’ V8 petrol engine was based on the 5.7-litre unit, but had a forged crankshaft, lighter pistons, strengthened connecting rods and a compression ratio of 10.3:1. Furthermore, the 6.1-litre V8 engine did not have MDS.

The 3.0-litre turbo-diesel and 3.7-litre V6 petrol engines were mated to Mercedes-Benz’s five-speed W5A580 automatic transmission, while the 4.7-, 5.7- and 6.1-litre V8 petrol engines were mated to Chrysler’s 545RFE five-speed automatic transmission.

Dimensions

Compared to the WG2 Grand Cherokee , the WH Grand Cherokee was 140 mm longer (at 4750 mm), 34 mm wider (1870 mm), 22 mm lower (1740 mm) and had a 89 mm longer wheelbase (2780 mm). Furthermore, the WH chassis achieved a 60 per cent increase in torsional rigidity.

Suspension

The WH Grand Cherokee had all-new independent front suspension with short and long arms and five-link rear suspension with a track bar.

Jeep WH.I Grand Cherokee specifications
Variant	Edition	Year	Engine	Trans.	Peak power	Peak torque
3.0L CRD	Laredo, Limited	2005-08	3.0-litre OM642 turbo-diesel V6	5sp auto	160 kW at 4000 rpm	510 Nm at 1600 rpm
3.7L V6	Laredo	2007-08	3.7-litre petrol V6	5sp auto	148 kW at 5100 rpm	315 Nm at 3900 rpm
4.7L V8	Laredo, Limited	2005-08	4.7-litre petrol V8	5sp auto	170 kW at 4500 rpm	410 Nm at 3600 rpm
5.7L HEMI V8	Limited	2005-08	5.7-litre ‘Hemi’ petrol V8	5sp auto	240 kW at 5000 rpm	500 Nm at 4000 rpm
6.1L HEMI	SRT-8	2006-08	6.1-litre ‘Hemi’ petrol V8	5sp auto	313 kW at 6000 rpm	569 Nm at 4600 rpm

Quadra-Trac II and Quadra-Drive II

With the exception of the SRT-8 editions, all WH Grand Cherokees had a permanent four-wheel drive system which provided a default front/rear torque split of 48:52. The 3.7L V6 and 4.7L V8 Laredo editions were fitted with Jeep’s Quadra-Trac II 4WD system which had an electronically-controlled multi-plate clutch that could proactively lock the centre differential if a loss of traction was anticipated. The Quadra-Trac II system could also brake an individual wheel to transfer torque to the opposing wheel (i.e. cross-axle torque transfer).

The 3.0 CRD and 5.7L HEMI variants were fitted with the more advanced Quadra-Drive II system which also included front and rear electronic limited slip differentials which could provide variable torque up to full axle lock.

SRT-8: electronic clutch packs

The SRT-8 was predominantly rear-wheel drive, with only 5-10 per cent of the engine’s torque directed to the front axle in normal conditions. If slippage was detected however, the SRT-8’s transfer case with electronic clutch packs could transfer up to 50 per cent of the engine’s torque to the front axle. Unlike the other Grand Cherokees, the SRT-8 was not equipped with low-range gearing while the front and rear differentials were open, with no limited-slip capability.

Safety equipment

Safety equipment for the WH.I Grand Cherokee included dual front airbags, front side airbags, front and rear curtain airbags, ABS, brake assist, electronic brake force distribution, electronic stability control, traction control, rollover stability control (‘electronic rollover mitigation’), load-limiting seatbelts for all seats, front seat seatbelts with pretensioners and load limiters, hill descent control and hill start assist.

Euro NCAP crash testing

In Euro NCAP crash testing , a WH Grand Cherokee 3.0L CRD received a four star adult occupant protection rating with a score of 26.49. In the frontal offset crash test, the Grand Cherokee scored 9.49 out of 16 as protection from serious chest injury was weak for the driver, while leg protection for both front occupants was marginal.

Features: Grand Cherokee Laredo, Limited and SRT-8

Standard features for the Grand Cherokee Laredo included 17-inch satin-finish alloy wheels, a six speaker sound system with CD player, dual zone climate control air conditioning, an eight-way power adjustable driver’s seat, four-way power adjustable front passenger seat, cruise control, 60/40 split and folding rear seats, tilt-adjustable steering wheel, tinted windows, tyre-pressure sensors, remote central locking and immobiliser.

Beyond this, the Grand Cherokee Limited added 17-inch polished aluminium wheels, a six speaker Boston Acoustics sound system with 276 watt amplifier and six-stack CD player, two-tone leather seats with memory settings, heated front seats, rear parking sensors, front fog lamps, rain-sensing wipers, electrochromic (i.e. auto-dimming) rear view mirrors and a leather-wrapped steering wheel.

The Grand Cherokee SRT-8 was distinguished by its 20-inch alloy wheels with sports suspension, embossed leather seats and upgraded brakes (including four-piston front brake calipers).

2006 Grand Cherokee Navigator

In March 2006, limited-run Navigator badged models were released; these models added touch-screen satellite navigation, headlight protectors, slim-line weather shields, aluminium side steps, nudge bar, roof racks and a towbar.

2006 Grand Cherokee 65th Anniversary edition

In 2006, 65th Anniversary editions of the 3.0L CRD and 4.7L V8 were released. Compared to the Laredo editions, the 65th Anniversary editions added a six speaker Boston Acoustics sound system with 276 watt amplifier and six-stack CD player, front fog lights, floor mats, power sunroof and cargo net. Visually, the 65th Anniversary editions were distinguished by their body-coloured door handles and side protection mouldings.

Review: Jeep WH.II Grand Cherokee (2008-10)