|
At this point of the job, nearly all of the hard work is done. There remain only one or two more tricks to getting the timing
belt installed correctly. Given that you have (presumably) taken the time to correctly position the # 1 piston to TDC, you
are ready to go.
First, take the timing belt and align it over the front (left) cam sprocket, the crank sprocket and the tensioner. The
tensioner spring will typically still be off at this stage. You want to make sure that the timing marks are lined up for
these two.
Note that the timing mark on the L front cam sprocket is off about a half-notch clockwise. This is deliberate, allowing
the cam sprocket to rotate backwards into position a half-notch as the belt takes up tension. This helps avoid the "off
by one notch" problem. The timing belt teeth must line up EXACTLY with the marks, and can't be off by even one notch/tooth.
Here you will need the strap wrench to re-position the left (rear) cam sprocket, either 90 degrees clockwise or counter-clockwise.
It should balance in place enough for the timing belt to be mounted. Again, rotate it just a half-notch clockwise past the
mark. This way, the tension pulling both cam sprockets counter-clockwise will tighten the belt in correct position. Also
check its position on the waterpump pulley.
With the belt daintily mounted just so, and the tensioner spring loose, bring the belt around the tensioner and place some
pressure to the right to keep the belt in place. Then, with herculean strength, use a needle-nose pliers to expand the spring
and hook it around the WP mounting post in the notch.
Check the timing marks again.
At this point, a final check of the timing marks is made. Also, check that the distributor rotor is pointing at the mark
you made on the distributor body.
One last check of the timing setup for the truly paranoid and compulsive. This is the "straw test". Ideally,
remove the #1 plug and place a straw (attached to a large clamp so it cannot be lost) and lower it into the cylinder. If
you are lined up correctly, the straw should immediately come into contact w/ the cylinder head, verifying the position of
# 1 piston at TDC.
On this engine, the # 1 plug is very hard to get at, however. An alternative is to check this when you have the left
rear timing cover removed, along with the alternator bracket (see below). Another is to use the #2 piston, and verify that
it is approaching TDC, i.e. just below the cylinder top. Since this fires next, you should be good. Also, you can rotate
the crankshaft 60 degrees clockwise to bring #2 to TDC and do the straw test on that cylinder.
Make sure that the timing belt tensioner is torqued to specifications. Now rotate the crankshaft through one entire cycle
to verify the position of everything, and to see that it does not slip. The spring on the tensioner should provide the correct
tension for the belt. You will need to briefly remount the crank bolt for this.
If you have removed the cam sprockets and only tightened them a little, be sure to torque them (70 ft-lbs) before you move
on.
The best way to do this is to fashion a tool out of a piece of straight iron and two short, squat bolts to fit into the
holes off-center on the cam sprockets. This tool can be used to hold the sprocket while the main bolt is torqued -- see tool
in photo. (Do not use this tool to hold the cam sprocket in place while torquing the crank bolt as shown in this photo --
you will cause the timing belt to slip).
At this point, engine re-assembly is not difficult if you have been organized. First, replace the timing covers, taking care
with which bolts go where. Just slightly tight only or you will break the plastic.
Next, remount the engine support bracket. Torque them per then manual. Remember to tighten the loose power steering pump
bracket bolts under the engine. Then replace the engine mount and the idler pulley. Remove the supports from under the engine.
After that, you can remount the engine dampener on the crankshaft. I used a propane torch to warm it up so it slipped more
easily over the crankshaft. After it cools, re-mount the main crank pulley and A/C accessory pulley.
At this point, you must torque the crank pulley. You can get it a little tight by removing the front (R) timing cover
and holding the cam sprocket in place. This runs the risk of slipping the timing belt.
There is really only one way to do it right on an automatic transmission, and that is to use a air impact wrench. If
you don't have one, you can pull the starter and wedge something against the flywheel .... not very elegant. (On the manual
transmission, put the car in 5th and have someone stand on the brakes).
Finally, replace both accessory belts. Remember to tension adjust the A/C belt. Re-mount the distributor cap, and re-attach
all of the wires to their appropriate plugs. Don't forget to tighten any plugs you have loosened in the process. Also remember
to re-assemble any part of the cooling system (e.g. fill the radiator).
Do a final check. Make sure there is oil in the engine. Also verify that the cooling system is all tightened up. As
a last step, re-attach the battery cables and then try a re-start. Check for oil leaks and listen to the engine through a
few gentle revs. Re-mount the wheels, drop the jackstands and you are ready to go.
Mitsubishi 3.0 SOHC Engine Home Page
|
