REMOVAL & INSTALLATION
B27F, B28F, and B280F Engines
See Figure 1
- Remove the timing chain cover as outlined previously.
- Remove the oil pump sprocket and drive chain.
- Loosen the tension in both camshaft timing chains by rotating each tensioner lock 1 / 4 turn counterclockwise and pushing in the rubbing block piston.
- Remove both chain tensioners. Remove the two curved and the two straight chain damper/runners.
- Remove the camshaft sprocket retaining bolt (10mm Allen head) and the sprocket and chain assembly. Repeat for other side.
- Install the chain tensioners and tighten to 5 ft. lbs. (7 Nm). Install the curved chain damper/runners and tighten to 7-11 ft. lbs. (9-15 Nm). Install the straight chain damper/runners and tighten to 60 inch lbs. (81 Nm).
- Install the left side camshaft sprocket and chain first. Rotate the crankshaft (use crankshaft nut, if necessary) until no. 1 cylinder is at TDC. (At this point, the crankshaft key is pointing directly to the left side camshaft and the left side camshaft key groove is pointing straight up.)
- Place the chain on the left side sprocket so that the camshaft sprocket notchmark is centered precisely between the two white lines on the chain.
- Position the chain on the inner crankshaft sprocket, making sure that the other white line on the chain aligns with the crankshaft sprocket notch.
- While holding the left side chain and sprockets in this position, install the sprocket and chain on the left side camshaft (chain stretched on tension side) so that the sprocket pin fits into the camshaft recess.
- Tighten the sprocket center bolt to 51-59 ft. lbs. (69-80 Nm). Use a prytool to keep the cam from turning.
- To install the right side camshaft sprocket and chain, rotate the crankshaft clockwise until the crankshaft key points straight down.
- Align the camshaft key groove so that it is pointing in the position shown; at this position, the no. 6 cylinder rocker arms will rock.
- Place the chain on the right side sprocket so that the sprocket notchmark is centered precisely between the two white lines on the chain.
- Position the chain on the middle crankshaft sprocket, making sure that the other white line aligns with the crankshaft sprocket notch.
- Install the sprocket and chain on the camshaft so that the sprocket notch fits into the camshaft recess. Tighten the sprocket nut to 51-59 ft. lbs. (69-80 Nm).
- Rotate each of the chain tensioners 1 / 4 turn clockwise. The chains are tensioned by rotating the crankshaft two full turns clockwise. Recheck to make sure the alignment marks coincide.
- Install the oil pump sprocket and chain.
- Install the timing chain cover and engine accessories as outlined previously.