Engine Repair

How to Replace a Timing Belt

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"How to Replace a Timing Belt"
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1998-2004 3.2 V6 DOHC Isuzu Rodeo or Honda Passport

Timing belt Removal / Replacement / Installation / Setting Time / Changing / Step-by-Step Instructions / whatever you want to call it (complete idiots guide to changing your time belt)

One weekend I decided to tackle this job on my 2000 Isuzu Rodeo, it was the most technically involved thing I had ever done. I was sure I was going to have to call a tow truck and get my embarrassing failure to a real mechanic to finish my Rodeo.
The job itself is not inherently difficult; the lack of information is the hard part. With this "manual" I hope this takes a lot of guess work out of the job. All the credit of this article goes to a bunch of great guys at www.planetisuzoo.com (an awesome Isuzu discussion forum), if you have any questions please email me at dpdb6b@umsl.edu

1. Remove air duct tube on top of engine. Disconnect air tube and two smaller plug ins on air duct. (Flat head and Phillips head driver)

2. Remove spark plugs, coil packs, 12 small screws (5/8 plug socket, 8mm socket or Phillips head)

3. Remove top radiator hose completely with pliers. Pinch hose clamps to slide down. Remove only the top of the lower radiator hose and pull it back out of the way.

4. Remove accessory belt. Push forward on tensioner with a breaker bar. (14mm socket)

5. Remove fan by taking off 4 bolts. (12mm open end wrench and flat head to steady)

6. Remove fan shroud with two top bolts (10mm socket)

7. Remove fan pulley.

8. Remove triangular fan holder (like dummy water pump). Two bolts and one nut, 12mm socket

9. Remove accessory belt tensioner. One bolt in upper left hand corner and one Allen head in center of puller. 12mm socket and 8mm Allen wrench.

10. Remove accessory belt idler puller. One bolt through center. 14mm socket.

11. Remove the top right cover first; gently pry on the bottom of cover to avoid moving power steering pump. Second, remove top left timing belt cover. *Don't remove the lower cover just yet! 12mm socket to remove timing cover bolts-about 10 bolts w/ spacers and one nut.

12. Be sure to collect all rubber o rings from the rear of the covers and use sealant to reattach them also inspect the small grooved gasket on the back of each cover.

13. *IMPORTANT* Find TDC. Turn engine to top dead center by using the crank bolt and use lower timing belt cover markings. (Turn the crank until the solid white line lines up with the zero on the lower timing belt cover)

If you are like me and afraid of screwing up, do the following few steps to ensure you have the correct timing before the belt comes off and you're screwed forever!
Be sure to have two top timing belt covers off
Look at the two, newly exposed, cam bank sprockets, when the timing belt goes over them you should periodically see 3 white solid lines (maybe one dotted line, depends on belt brand) If lines on timing belt are worn off, ensure the crank is at TDC.
Now if you do still have the white lines on the belt, look an inch or two above the cam sprockets on the valve covers, there are two marks over each cam sprocket, the marks look like a small raised line about .5 of an inch long on the valve covers.
Turn the crank clockwise until you see the solid white line on the belt line up with each mark on the valve cover.

14. Remove crankshaft pulley with rented harmonic balancer puller. One big 7/8 bolt in center needs to be removed before the pulley is operated (if you have trouble getting it out use big breaker bar and have a friend tap the starter with the breaker pinned up against the radiator hose housing on top of the engine). Be careful not to damage the threads on big crank bolt. When using crank puller only use two bolts on the face on the pulley.

15. Now remove the lower timing belt cover. Be sure to keep track of all the little black rubber o rings on the covers. (12mm socket, maybe 5 bolts)

16. DO NOT MOVE THE CRANK OR CAM GEARS FROM HERE UNTIL YOU GET THE NEW BELT ON. Loosen the top bolt on the timing pulley tensioner (it looks about four inches long with a little rod coming from the center of one end). Now, remove the bolt on the bottom. Now, remove the top bolt and take the tensioner to a vice or c clamp and compress the little rod and stick a finishing nail into the side of it and through the rod in the tensionor to hold that rod back. (12mm socket, two bolts)

17. Remove the timing belt. It probably won't look too bad, trust me get rid of it and remember you are doing this for a good preventative cause.

18. Now is the time to remove and replace the water pump, idler, idler pulley, and idler pulley tensioner (strongly recommend changing all of these parts now). Remember with the water pump, the top right bolt hole will stay empty because the fan bracket will fill it, eventually.

19. Make sure the engine didn't move, if it did. Its okay, follow these steps before continuing:
Turn the lower crank pulley clockwise until the keyway and small cut out one the rear pulley line up with a small mark/line on the engine, pretty much turn the keyway to the three o'clock position. Look at the nine o'clock position on the crank pulley, can you see or feel a small notch cut into the face of the pulley? That notch should be at the nine o'clock position.
Next turn the passenger side cam bank pulley until it "springs" into lining up with that mark on the valve cover. Do not just simply turn it into place; it must "spring" there on its own. (14mm socket to turn the pulley)
Next look at the driver's side cam bank pulley. Just behind the pulley and to the left you will see a small raised line. Turn the cam sprocket until it "springs" into that line. Next, turn the pulley until it gets to the raised line on the valve cover. Don't let it "spring into place", just crank it there.
That's it now the engine is in time, again!

20. Now put the belt on. When you put the belt on, you want all 3 white solid lines on the belt to line up with the two lines on the valve covers and the nine o'clock notch on the crank. It will take a little trying to get them all to line up, but take your time and ensure they do. If they don't line up, the timing will be off and you will be mad when you reassemble everything and its one tooth off.

21. Tips to putting on the belt: use big paper clamps or vice grips to hold the belt on pulleys. If your having trouble getting that bottom lined up on the crank right. Rotate the engine slightly either clockwise or counterclockwise to give your self a little slack. If you do that: double, triple, etc check you still have all your lines lined up.

22. Once the belt is on, take that tensioner rod and put it back on the engine, pull the pin/nail out and it will take the slack out.

23. Rotate the engine a few times to be sure you're all good with your marks.

24. Reassemble the engine and stick your chest out because you are officially the man!

More about this author: David Diercks

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