Thursday, August 4, 2011

How to replace drive shaft or harmonic balancer on 1993 toyota previa

Front Driveshaft and Universal Joints



REMOVAL & INSTALLATION



See Figures 1 through 10

  1. Jack up the front of the vehicle and support with jackstands.
  2. Place matchmarks on the flanges. Remove the 4 nuts and bolts.



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Fig. Fig. 1: ALWAYS matchmark with paint prior to separating the driveshaft from the vehicle

  1. Remove the front driveshaft dust cover. Some types are equipped with 2 bolts, while others use 4.
  2. Remove the driveshaft dust cover subassembly. The three bolts are two different sizes.

The driveshaft dust cover is located around the outer portion of the U-joint. On some models you may have an upper and lower.

  1. Suspend the front side of the driveshaft.
  2. Place matchmarks on the flanges. Remove the 4 nuts and bolts.
  3. Remove the front driveshaft.

To install:
  1. Align the matchmarks on the rear flanges, then connect the flanges with the nuts and/or bolts. Tighten to 54 ft. lbs. (74 Nm).
  2. Install the front driveshaft dust cover subassembly. Tighten bolts A to 27 ft. lbs. (36 Nm) and B to 17 ft. lbs. (23 Nm).
  3. Align the matchmarks on the front flanges, then connect the flanges with the bolts and nuts. Tighten to 54 ft. lbs. (74 Nm).
  4. Install the front driveshaft dust cover. Tighten the bolts to 13 ft. lbs. (17 Nm) and the nuts to 10 ft. lbs. (13 Nm).
  5. Attach the rear driveshaft flange to the companion flange on the transfer case. Align the matchmarks on the flanges, then connect the flanges with the bolts and nuts. Tighten to 54-56 ft. lbs. (74-76 Nm).
  6. Lower the vehicle and road test it.



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Fig. Fig. 2: Remove the front dust cover retaining bolts



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Fig. Fig. 3: The matchmarks on the flanges are helpful in installation for lining things up correctly



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Fig. Fig. 4: Tighten bolt A to 27 ft. lbs. (36 Nm) and B to 17 ft. lbs. (23 Nm)



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Fig. Fig. 5: Exploded view of the front driveshaft-1989-95 4WD Pick-Up and 4Runner except with 3VZ-FE engine



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Fig. Fig. 6: Exploded view of the front driveshaft-1989-95 4WD Pick-Up and 4Runner with 3VZ-FE engine



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Fig. Fig. 7: Exploded view of the front driveshaft-4WD



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Fig. Fig. 8: Exploded view of the front driveshaft-4WD



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Fig. Fig. 9: Exploded view of the front driveshaft-4WD



U-JOINT REPLACEMENT



See Figures 11 through 15

  1. Raise and support the vehicle.
  2. Remove the driveshaft.
  3. Matchmark the yoke and the driveshaft.



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Fig. Fig. 11: Always place matchmarks on the spider and yoke

  1. Remove the snaprings from the bearings. There are two types of snaprings; Toyota and Dana.



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Fig. Fig. 12: Tap out the Toyota type snaprings



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Fig. Fig. 13: Pull out the snaprings-Dana type

  1. Position the yoke on vise jaws. Using a bearing remover and a hammer, gently tap the remover until the bearing is driven out of the yoke about 1 in. (25mm).



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Fig. Fig. 14: An SST such as 09332-25010 is used to extract the bearings

  1. Place the tool in the vise and drive the yoke away from the tool until the bearing is removed.
  2. Repeat Steps 4 and 5 for the other bearings.
  3. Check for worn or damaged parts. Inspect the bearing journal surfaces for wear.

To assemble:
  1. Install the bearing cups, seals, and O-rings in the spider.
  2. Apply multi-purpose grease to a new spider and bearings. Be careful not to apply too much grease.
  3. Position the spider into the yoke.
  4. Start the bearings in the yoke, then press them into place, using a vise. Repeat for the other bearings.
  5. If the axial play of the spider is greater than 0.0020 in. (0.05mm), select snaprings which will provide the correct play. Be sure that the snaprings are the same size on both sides or driveshaft noise and vibration will result.
  6. Check the U-joint assembly for smooth operation.



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Fig. Fig. 15: Check the axial play after reassembly

When replacing the driveshaft U-joints on a 4WD vehicle, be sure that the grease fitting is accessible after the joint is assembled.

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Center Bearing


REMOVAL & INSTALLATION



The center support bearing is a sealed unit which requires no periodic maintenance. The following procedure should be used if it becomes necessary to replace the bearing. Toyota does not supply individual parts for the bearing replacement only the assembly. See your local jobber if necessary.

  1. Remove the intermediate driveshaft and the center support bearing assembly.
  2. Paint mating marks on the universal joint flange and the intermediate driveshaft.
  3. Remove the cotter pin and castle nut from the intermediate driveshaft; the nut will be staked. Remove the universal joint flange from the driveshaft using a press.
  4. Remove the center support bearing assembly from the driveshaft.
  5. Remove the two bolts from the bearing housing and remove the housing.
  6. Remove the dust deflectors from both sides of the bearing cushion. Remove the dust deflectors from either side of the bearing.
  7. Remove the snaprings from each side of the bearing. This is easy to do if you have a snapring tool which fits the holes in the ring, and very difficult otherwise. Remove the bearing.

To assemble:
  1. Install the new bearing into the cushion and fit a snapring on each side.
  2. Apply a coat of multi-purpose grease to the dust deflectors and put them in their respective places on each side of the bearing. The single deflector with a slightly larger diameter goes on the rear of the bearing.
  3. Press the dust deflector onto each side of the cushion. The water drain holes in the deflectors should be in the same position on each side of the cushion. The water drain holes should face the bottom of the housing.
  4. Press the support bearing assembly firmly onto the intermediate driveshaft, with the seal facing front.
  5. Match the mating marks painted earlier, and install the universal joint flange to the driveshaft. Install the center bearing on the intermediate shaft and tighten the nut to 134 ft. lbs. (181 Nm). Loosen the nut and then retighten it to 51 ft. lbs. (69 Nm). Stake the nut.

Check to see if the center support bearing assembly will rotate smoothly around the driveshaft.

  1. When reinstalling the driveshaft, be certain to match up the marks on both the front transmission flange and the flange on the sleeve yoke of the rear driveshaft.
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The role of the harmonic balancer is to absorb energy and reduce vibrations in the crankshaft. It is an important component because the vibrations can be strong enough to damage the engine
, as well as the accessories driven by it. The balancer is a composite device made up of metal and rubber parts. Rubber is prone to deterioration and this can cause slipping or even complete failure. Changing a balancer is a difficult task that should be left to a professional mechanic but it can also be done at home. Special tools are available that can help with this task, such as the harmonic balancer puller.-------- The harmonic balancer is located at the lower front of the engine. It is attached to the free end of the crankshaft, opposite the end that is joined to the clutch and transmission. The balancer is comprised of a metal inner hub and outer disc, with a thick rubber layer between them. The size and weight of the parts are designed to absorb specific vibration frequencies. This means that a balancer should only be used on an engine it was designed for, otherwise it will not be as effective. Most balancers will either have groves or a separate pulley attached to them for driving the accessory belts.--------

As with all engine components, the harmonic balancer will eventually fail and need to be replaced. The rubber layer between the metal parts is often the source of the failure. The adhesive bond between them can fail and cause the parts to slip, reducing the amount of power transferred. The engine accessories may not function properly when this happens as they do not turn at the required speed. The rubber can also break apart internally and cause a total failure of the balancer. Cracks on the visible edge of the rubber layer are a sign that it is deteriorating. The seal behind the balancer should also be replaced if there is oil leaking from it, as oil makes the rubber deteriorate faster.

It is often difficult to remove the harmonic balancer because of its tight fit with the crankshaft. However, a special tool called a balancer puller can make the task easier. The puller is a metal hub that attaches to the balancer with several bolts, and has a center bolt that presses against the end of the crankshaft. When the center bolt is turned, the puller pushes against the crankshaft and draws the balancer off it. After the balancer has been removed, the shaft key and slot should be inspected for damage and the key replaced if there are any chips or cracks.

Installing a harmonic balancer can be just as difficult as removing it. The contact surfaces on the crankshaft and balancer should be lightly oiled so that they slide together more easily. The balancer can be pushed onto the crankshaft by turning a bolt in the center hole. Since the locking bolt is too small for this, a larger bolt must be found with the same thread. To avoid stripping the thread in the crankshaft, the bolt should have several turns on it before any force is applied. It may be necessary to first tap the balancer on with a rubber mallet. Once the balancer is on the crankshaft, the locking bolt is secured with the correct torque.

The harmonic balancer in your Toyota is the crankshaft pulley. The balancer helps to reduce the effect of resonance that originates from the natural combustion cycle in your engine. This resonance, if left unchecked, could cause the crankshaft to fail. Under normal circumstances, you should never have to replace the harmonic balancer, but you may need to remove it in order to change the timing belt.

  • Loosen the lug nuts on your driver's side wheel. You will turn the lug nuts only 45 degrees counterclockwise to do this.

  • Jack up on the front jack point located behind the radiator.

  • Place jack stands underneath the front pinch welds. On the Toyota , these will be located under the driver's and passenger's front door (under the car). Or in two door models, near the front of the driver's and passenger's door. Lower the car onto the jack stands.

  • Finish loosening the lug nuts and remove the wheel

  • Pry the plastic rivets out of the splash guard in the wheel well and remove the splash guard.

  • Locate the harmonic balancer. It will be the pulley directly behind the splash guard you just removed.

  • Loosen and remove the crank pulley bolt that holds the harmonic balancer in place using the crankshaft bolt remover tool. The tool prevents the pulley from moving while you loosen the bolt. You'll have to use an impact gun to loosen this bolt.

  • Place the crank pulley remover tool over the harmonic balancer and turn the tool's bolts clockwise to pull the balancer off. This tool will grab the pulley and let you pull it off the crankshaft. To do this, it has "arms" that grab the side of the pulley, and a bolt that pushes against the end of the crankshaft to pry the pulley off.


  • Use an impact wrench. The 3/8 inch models do not have enough torque for this job so use a 1/2 in wrench. Jam the belt with a piece of wood so the pulley doesn't turn. Use an socket designed for an impact wrench, which has a tighter fit on the crankshaft (or "harmonic balancer") bolt head than a socket meant for a hand tool. This will keep you from marring the bolt head. The bolt is threaded normally, not reverse threaded.

    I am a believer in using hand tools wherever possible. The service manual shows the use of a special hand tool. It is a semi-circular piece of metal attached to a handle. The semicircle is attached to the crankshaft pulley by two bolts that go through two holes that you can see in the pulley. The idea is to hold the pulley with this tool. The semicircle leaves the pulley bolt exposed so you can put a wrench over it and turn it. However it would be hard to find this tool for sale in the USA. To losen the pulley bolt you will need a breaker bar with a long extension. If you have the car up on a lift then you have room for a long handle, but if you have it on jackstands you won't. My conclusion is that the impact wrench is the practical way.





    Camshaft Sprockets or Pulleys


    REMOVAL & INSTALLATION



    22R and 22R-E Engines

    See Figures 1 through 6

    The cam sprocket is removed from the camshaft as part of the rocker assembly removal. If the sprocket is to be removed from the chain, support the chain with a piece of wood, keeping the chain engaged to the lower sprocket. If the chain comes off the bottom sprocket, the timing chain covers must be removed and the chain correctly installed. Refer to Timing Chain Removal and Installation in this section.

    1. Remove the valve cover.
    2. Turn the crankshaft until the No. 1 cylinder position is set at TDC compression. Matchmark the sprocket and chain.



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    Fig. Fig. 1: Matchmark the chain and sprocket

    1. Remove the halfmoon plug from the front of the cylinder head.



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    Fig. Fig. 2: Remove the halfmoon plug located at the front of the cylinder head

    1. Unbolt the cam sprocket.



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    Fig. Fig. 3: Loosen and remove the drive gear bolt

    1. Remove the distributor drive gear and camshaft thrust plate.



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    Fig. Fig. 4: Pull the bolt and gear off the cam

    1. Remove the cam sprocket. Using a piece of wire, support the chain to keep it in position for sprocket installation.



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    Fig. Fig. 5: Lift the chain up, then slide the gear off the cam



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    Fig. Fig. 6: Secure the chain in place with a length of wire

    To install:
    1. While holding up on the sprocket and chain, turn the crankshaft until No. 1 and No. 4 cylinders reach TDC.
    2. Place the sprocket over the camshaft dowel. If the chain does not seem long enough on replacement, turn the crankshaft back and forth while pulling up on the chain and sprocket.
    3. Place the distributor drive gear and camshaft thrust plate over the chain sprocket. Tighten the bolt to 58 ft. lbs. (78 Nm).
    4. Install the halfmoon plug on the cylinder head.
    5. Install the valve cover.

    3VZ-E Engines
    1. Remove the timing belt.
    2. Use a properly installed counter-holding tool, remove the pulley bolt, the pulley and the match pin. Note that the left and right pulleys are different; label them to avoid confusion at reassembly.


    WARNING
    Do not attempt to use the timing belt to hold tension on the pulley while loosening or tightening the retaining bolt.

    To install:
    1. Align the camshaft match pin hole with the marks on the upper rear timing belt cover. This places the pin holes straight up.
    2. Install the timing pulleys, observing correct placement of the left and right pulleys. Install the bolts, but do not install the match pin. Check that the bolt head is not touching the pulley (Its not completely tight yet). Align the timing mark on each pulley with the marks on the No. 3 timing cover.
    3. Install the timing belt, following the procedures given in this section. After the engine has been rotated two full revolutions and the timing marks checked, tighten the idler pulley bolt.
    4. Remove the camshaft timing pulley bolts. Align the pulley match pin hole with the hole in the camshaft; install the match pin. Reinstall the camshaft pulley bolts.
    5. Using a properly installed counter-holding tool, tighten the pulley bolts to 80 ft. lbs. (108 Nm). Take great care not to nick or damage the timing belt.
    6. Continue with the re-installation of the timing belt.

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    Driven Disc and Pressure Plate


    REMOVAL & INSTALLATION



    See Figures 1 through 27


    CAUTION
    The clutch driven disc may contain asbestos, which has been determined to be a cancer causing agent. Avoid inhaling any dust from any clutch surface! When cleaning clutch surfaces, use a commercially available brake cleaning fluid. Never clean clutch surfaces with compressed air.

    1. Remove the transmission.



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    Fig. Fig. 1: View of the clutch and pressure plate assembly

    1. Matchmark the clutch cover (pressure plate) and flywheel, indicating their relationship.



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    Fig. Fig. 2: Matchmark the pressure plate and flywheel



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    Fig. Fig. 3: Remove the clutch and pressure plate bolts

    1. Loosen the clutch cover-to-flywheel retaining bolts one turn at a time in a crisscross pattern. The pressure on the clutch disc must be released GRADUALLY.



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    Fig. Fig. 4: Carefully pry the clutch and pressure plate assembly away from the flywheel

    1. Remove the clutch cover-to-flywheel bolts. Remove the clutch cover and the clutch disc.



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    Fig. Fig. 5: Remove the clutch and pressure plate



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    Fig. Fig. 6: View of the flywheel once the clutch assembly is removed

    1. If the clutch throwout bearing is to be replaced, do so at this time as follows:



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    Fig. Fig. 7: Lock the flywheel in place, then remove the flywheel bolts



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    Fig. Fig. 8: Removing the flywheel from the crankshaft

    1. Remove the bearing retaining clip(s) and remove the bearing and hub.
    2. Remove the release fork and the boot.
    3. The bearing is press fit to the hub. Turn the bearing by hand while placing it under some pressure; check for freedom of motion and lack of grinding or resistance. The bearing is permanently lubricated and cannot be disassembled or greased.
    4. Clean all parts; lightly grease the input shaft splines and all of the contact points.
    5. Install the bearing/hub assembly, fork, boot, and retaining clip(s) in their original locations.



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    Fig. Fig. 9: Add a threadlocking agent to the flywheel bolts upon installation



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    Fig. Fig. 10: Be sure that the flywheel surface is clean, before installing the clutch



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    Fig. Fig. 11: Place a straightedge across the flywheel surface, then use a feeler gauge to check for warpage



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    Fig. Fig. 12: Checking the pressure plate for excessive wear

    1. Inspect the flywheel surface for cracks, heat scoring (blue marks), and warpage. If oil is present on the flywheel surface, this indicates that either the engine rear oil seal or the transmission front oil seal is leaking. If necessary, replace the seal(s). If in doubt concerning the condition of the flywheel, consult an automotive machine shop.



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    Fig. Fig. 13: Install a clutch alignment arbor, to align the clutch assembly during installation



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    Fig. Fig. 14: Clutch plate installed with the arbor in place



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    Fig. Fig. 15: Clutch plate and pressure plate installed with the alignment arbor in place



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    Fig. Fig. 16: Pressure plate-to-flywheel bolt holes should align

    1. Before installing any new parts, make sure that they are clean. During installation, do not get grease or oil on any of the components, as this will shorten clutch life considerably. Grease or fingerprints may be cleaned with an evaporative cleaner such as the type used on brake linings.



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    Fig. Fig. 17: Apply locking agent to the clutch assembly bolts



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    Fig. Fig. 18: Be sure to use a torque wrench to tighten all bolts in a star pattern



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    Fig. Fig. 19: Grease the clutch release fork ball

    To install:
    1. Position the clutch disc against the flywheel. The long side of the splined section faces the flywheel.
    2. Install the clutch cover over the disc and install the bolts loosely. Align the matchmarks made. If a new or rebuilt clutch cover assembly is installed, use the matchmark on the old cover assembly as a reference.



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    Fig. Fig. 20: View of the clutch release fork; check it for signs of damage



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    Fig. Fig. 21: View of the clutch release fork bearing clips; make sure these are not bent or broken



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    Fig. Fig. 22: Removing the clutch release fork bearing clips



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    Fig. Fig. 23: Grease the throwout bearing assembly at the outer contact points



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    Fig. Fig. 24: Grease the throwout bearing assembly at the inner contact points

    Whenever the clutch disc is replaced, replacement of the pressure plate (clutch cover) and release bearing is highly recommended.

    1. Align the clutch disc with the flywheel using a clutch aligning tool. These handy tools are available in many auto parts stores at a reasonable price. Do NOT attempt to align the clutch disc by eye; use an alignment tool.



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    Fig. Fig. 25: Installing the clutch release fork bearing clip



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    Fig. Fig. 26: View of the clutch release fork assembly installed; be sure all parts move freely



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    Fig. Fig. 27: Exploded view of the common clutch set-up

    1. With the clutch aligning tool installed, tighten the clutch cover bolts gradually in a star pattern, as is done with lug nuts. Final tighten the bolts to 14 ft. lbs. (19 Nm).
    2. Apply molybdenum disulfide grease or multi-purpose grease to the release fork contact points, the pivot and the clutch disc splines. Install the boot, fork, and bearing on the transmission input shaft.
    3. Install the transmission.

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