See Figures 1, 2, 3, 4, 5 and 6
The 2.5L engine is equipped with 2 balance shafts located in a housing attached to the lower crankcase. These shafts are driven by a chain and 2 gears from the crankshaft at 2 times crankshaft speed. This counterbalances certain engine reciprocating masses.
REMOVAL & INSTALLATION
- Remove the engine from the vehicle.
- Remove the timing case cover, timing belt and sprockets.
- Remove the engine oil pan.
- Remove the front crankshaft seal retainer.
- Remove the balance shafts chain cover.
- Remove the chain guide and tensioner.
- Remove the balance shafts sprocket retaining screws and crankshaft chain sprocket Torx® screws. Remove the chain and sprocket assembly.
- Remove the balance shafts carrier front gear cover retaining double ended stud. Remove the cover and balance shafts gears.
- Remove the carrier rear cover and balance shafts.
- To separate the carrier, remove the 6 crankcase-to-carrier attaching bolts and remove carrier.
- Take notice of all parts to avoid interchanging.
- Install both shafts into carrier the assembly from rear of carrier.
- Install the rear cover.
- Install the balance shafts drive and driven gears to shafts.
- Position the carrier assembly on crankcase, then tighten the 6 crankcase-to-carrier bolts to 40 ft. lbs. (55 Nm).
- Crankshaft-to-balance shaft timing must be established. Rotate both balance shafts until the key ways are in the Up position.
- Install the short hub drive gear on balance shaft driving shaft.
- Install the long hub gear on the driven shaft.
- With both gears on the balance shafts and key ways Up, the timing marks should be meshed.
- Align the balance shaft carrier cover with the carrier housing dowel pin and install double ended stud. Tighten to 105 inch lbs. (12 Nm).
- Install the crankshaft sprocket and tighten sprocket Torx® screw to 11 ft. lbs. (15 Nm).
- Turn the crankshaft until number one cylinder is at TDC. The timing marks on the chain sprocket should line up with the parting line on the left side of number one main bearing cap.
- Install the chain over the crankshaft sprocket so the nickel plated link of the chain is over the timing mark on the crankshaft sprocket.
- Install the balance shaft sprocket into the timing chain so that the timing mark on the sprocket (yellow dot) mates with the yellow painted link on the chain.
- With the balance shaft key way in 12 o'clock position slide the balance shaft sprocket on the nose of the balance shaft. The balance shaft may have to be pushed in slightly to allow for clearance.
The timing mark on the sprocket, the painted link, and the arrow on the side of the gear cover should line up if the balance shafts are timed correctly.
- Install the balance shaft bolt, then tighten it to 21 ft. lbs. (28 Nm). Place a wooden block between the crankcase and crankshaft counterbalance to prevent crankshaft from turning.
- Proper balance shaft timing chain tension must be established.
- Place a shim 0.039 in. (1mm) thick by 2.75 in. (70mm) long between the chain and tensioner.
- Apply firm hand pressure behind the adjustment slot and tighten adjustment bolt first, followed by the pivot screw to 105 inch lbs. (12 Nm). Remove the shim.
- Install the chain guide making sure the tab on the guide fits into slot on the gear cover. Install the nut and washer, then tighten them to 105 inch lbs. (12 Nm).
- Install the chain cover, then tighten the screws to 105 inch lbs. (12 Nm).
- Apply a 1 / 16 in. (1.5mm) diameter bead of RTV gasket material to retainer sealing surface. Install retainer assembly.
- Install the crankshaft sprocket and timing belt. For more details, refer to the timing belt adjustment procedure in this section.
- Install the timing cover.