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Timing Belt Change -- Page 5
Replacing Cam Seals & Alternator
Replacing PCV Valve
Waterpump and Thermostat
Replace Timing Belt and ReAssembly
Timing Belt Change -- Page 2
Timing Belt Change -- Page 3
Timing Belt Change -- Page 4
Changing the Spark Plugs
Timing Belt Change -- Page 1
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Mitsubishi 3.0 SOHC Engine

Changing the Timing Belt -- Page 5

Time to get serious about the timing belt cover. This is a 3-piece item, with a v-shaped lower piece that fits over the crankshaft. The two upper-pieces are "Mickey Mouse" ears which cover the camshafts. They are not identical, and have a tendency to break.

timing_cover_upperfront_left_bolts.jpg

timing_cover_main_withbolts.jpg

The three covers are held on by a gaggle of 10mm bolts of different lengths. At least one on the left (front of car) also holds the wiring harness to the A/C compressor. Remove all 3 timing covers, carefully noting the bolt position and sizes.

timing_cover_inplace_labeled.jpg

After removing the covers, you can see the timing belt going around it's various attachments and accessories. The driving elements are the two camshaft sprockets (top), as well as the crankshaft sprocket (bottom). The tensioner (long arrow) is held with a simple spring to a notched post on the waterpump assembly (oval). The WP and tensioner turn on the flat side of the belt, while the drive elements turn on the toothed side.

timing_belt_old_labeled.jpg

Before you remove the belt, rotate the crankshaft so that the timing marks for the crankshaft and both camshaft sprockets are lined up. This means that the #1 piston is TDC, and that the valve trains are ready to open/close in concert with the pistons. Also double check that the distributor rotor is pointing at your mark for the #1 plug wire.

If they are not already marked, use white paint or chalk to highlight the camshaft sprocket timing marks. They should line up with the notches on their respective rear timing covers. The crank sprocket should line up with the nub on the oil pump.

cam_sprocket_front_timingmark_label.jpg

cam_sprocket_rear_timingmark_label.jpg

crankshaft_timing_mark.jpg

Now you can remove the belt. Loosen the timing belt tensioner bolt, and remove the spring from its post on the waterpump. This is tough to get off. Don't lose the spring. Check and make sure the tensioner spins with nearly no friction. If not, replace it.

timing_belt_tensioner_spring2.jpg

When you remove the belt, the crankshaft sprocket and the left (front) camshaft sprocket will remain in place. The right (rear) camshaft is in mid-cycle, and will likely rotate in either direction 90 degrees to its neutral point mechanically. A strap wrench can be used to rotate it back to the timing mark when you are ready to replace the timing belt.

Congratulations, you are ready to replace the timing belt ! This is what you should see.

timing_belt_removed.jpg

If you have not done so already, this is a good time to give the timing belt components a good cleaning.

Now you can replace the crankshaft front main seal. Remove the crankshaft sprocket. Mine slid off easily. The manual says that you sometimes have to drill tap holes and force it off. Hope not. If so, I might pass on the seal. For me, it was a source of major oil leak.

With a hand drill, make two very small holes in either side of the seal. Be careful not to scratch the crankshaft, or it "will leak forever". Then hand-screw some wood screws into the seal. Using two Vise-Grips, pull out the seal. Easy.

crank_front_main_seal_removal.jpg

Now replace the new seal by hand, and use a size of PVC pipe to tap the new seal in equally all around. Go nice and slow.

If the crankshaft is damaged, you can get a "sleeve repair" kit which fits over the crank to provide a new mating surface. These are also available for the camshafts. I bought these but did not use them.

crank_front_main_seal_install.jpg

Go ahead and replace the crankshaft sprocket, after lubricating it with anti-seize.

At this point, you have several options. First, you can simply replace the timing belt and beat a hasty retreat. If this is your first attempt at this kind of job, no-one would fault you. Start simple.

Timing Belt Replacement and Re-Assembly

Highly recommended at this stage is the waterpump. After this much disassembly, replacing it is easy and well worth it if the engine is > 150,000 miles.

Replace Waterpump and Thermostat

However, after all of this work, you are in the unique position of being able to replace the cam seals, which may be partly responsible for oil leaks. This job is not for the faint of heart, and requires a lot of dis-assembly. The cam seals themselves are a bit of a pain. However, it is a cool job, and one would hate to re-assemble the entire engine front only to discover that you needed to go all the way back inside. I would recommend it if you have a major oil leak despite replacing the PCV valve.

Replacing the Cam Seals + Alternator

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