| Timing-Belt Replacement, Pt. 2 -- Belt Removal |
From "Weekend Mechanic"
episode WKM-203 |
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With the radiator hoses, fan assembly and crankshaft pulley removed, there are still a few engine parts that need to be removed in order to gain access to the timing belt. Some of those parts will later be serviced or replaced. Important: Included below are the steps in this automotive procedure as shown in the episode. These steps are general guidelines that are applicable to most vehicles. With any particular vehicle, there may be procedures, specifications, settings, tolerances, components, etc. that are specific to that vehicle. There are also variations according to the type and brand of repair kit you select. Always consult your vehicle's service manual when undertaking significant automotive repairs, and read and follow the manufacturer's directions and precautions that come with your kit or replacement parts.
Accessing and Removing the Belt
- The next part to come off is the harmonic balancer -- a device that helps prevent vibration from damaging the crankshaft. It's held in place with a single bolt. Because the spec on this bolt is 130 foot-pounds, a breaker bar is required to loosen and remove the bolt (figure A).
- The harmonic balancer has some delicate components, and removing it requires a special tool known as a harmonic-balancer puller (figure B). The tool has a threaded rod and tapered end.
- The puller is bolted onto the balancer, and as it's tightened, it pulls the balancer off evenly (figure C). Be sure to use heavy-duty bolts in the puller. Make certain that the center piece is in straight and tighten it carefully to pull balancer off.
- With the balancer removed, it can be examined closely. The internal blades (figure D) pass through the crankshaft-position sensor with close tolerances. This assists in creating the spark that allows the engine to run. If the internal components of the balancer are damaged, or installed improperly, the sensor will be damaged and the engine won't be able to operate.
- Next, disconnect and remove the adjusting pulley (figure E) in order to access the timing cover.
- Loosen the securing clips on the timing cover (figure F) and carefully remove the cover to reveal the timing belt (figure G).
Important: Use caution when removing the plastic timing cover, as they damage easily. Note: Some vehicles have a timing chain rather than a belt. Although they perform the same function, they are not interchangeable.
- The timing belt has teeth that connects to the camshaft sprocket, the intermediate sprocket (figure H) and the crankshaft sprocket.
- The crankshaft (figure I) is the engine component that drives the belt and related accessories.
- The sprockets have factory-installed timing marks (figure J) to allow for proper alignment before removal. Use a breaker bar to turn the intermediate shaft until the timing marks match up. It's critical to do this before replacing the belt so that the timing will be correct when the new belt is installed.
- Use a marker to mark the positions of all the sprockets (figure K) to ensure that they can be positioned correctly later. (Leftover touch-up paint works well for this.)
- Before removing the belt, first loosen the tensioner bolts and pry the tensioner to the side.
- Retighten the tensioner bolt to hold the tensioner in place (figure L) and remove the belt (figure M).
- Once it's removed, inspect the old belt (figure N) for signs of oil or cracks. The belt will be replaced regardless, since it's replacement interval is past.
In the segment that follows, the some ancillary maintenance is performed, parts are replaced and the new belt is installed.
RESOURCES :
The Complete Idiot's Guide to Trouble-Free Car Care
Author: Dan Ramsey
ISBN: 0028635833
Alpha Books
How Cars Work
Author: Tom Newton
ISBN: 0966862309
Publisher: Black Apple Press
Auto Repair for Dummies
Author: Deanna Sclar
ISBN: 0764550896
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