How To: Timing Belt
Keeping Time
In our never-ending quest to help you maintain your whip, and save a buck in the process, we bring you a step-by-step on how to change a timing belt on the D series.
It's that toothed belt on the engine that the crankshaft uses to drive the camshaft(s), and while many of us never actually see it, most know it's pretty vital to the proper operation of the engine. We speak of course about the timing belt, and when it comes to replacing or even inspecting it, folks generally defer to anexpert. The only prolem is deferring to said expert can often exceed $250, a sizable sum if you're still in school or just working part time.
Because we have nothing but love for ALL of our readers, not just the rich one, we thought we'd show you how it's done. Or at least how it;s done on fifth and sixth gen single cam non VTEC D-series motors. Our M.E. extraordinare let us use his '99 Civic DX hatchback as the test subject, seeing that it already had 102,000 miles on it and the service manual recommends the belt be changed at 105k, and the entire process took us six hours, so it's definitely a weekend job. We also recommen that ou repace the tensioner and water pump while you're at it. And finally, despite what you may have seen or heard, you don't have to pull he engine. Perhaps more convenient, but not neccessary.
[1] We kick things off by raising the car and putting it up on jackstands. It's also necessary to remove the driver's side wheel and this long piece of useless plastic shielding underneath the front of the car for easier access to the crankshaft bolt.
[2] The spark plugs are removed, as are the plug cables. It's important to note the position of the terminals for all the plugs on the distributor cap; mess this up and your timing is completely fu**ed. Most terminals aren't marked, so follow the plug wire from the cylinder to the cap and remember which one goes where; the number one cylinder is normally the furthest to the right as you're facing the engine from the front of the car.
[3] Next, the valve cover comes off to access the plastic timing belt cover. The valve cover is typically secured with a handful of bolts.
[4] The drive belts are our next targets. For the power steering pump belt, loosen the pivot bolt (pictured) and pinch bolt underneath, then swing the pump out until the belt is loose enough to remove. For the alternator belt, the pivot bolt is underneath the alternator while the pinch bolt can be loosened from up top. Again, swing the alternator out until the belt is loose enough to remove.
[5] We have to unbolt the driver's side engine mount, but before we can we'll need to support the motor with a jack. A block of wood goes between the jack pad and the oil pan to avoid damaging the pan.
[6] Confident that the engine is safe, we remove
[7] Enough pieces are out of the way so we can easily remove the upper timing belt cover, so we unbolt it and take it out of the way.
[8] This next step is another critical one: setting the number one cylinder to top dead center (from here on out, TDC). Basically we need to turn the crankshaft with a socket and ratchet attached to the crank bolt until the number one piston is at TDC. Since this is a four-stroke engine, we know technically there are two TDCs, one for the compression stroke and one for the exhaust stroke. The one we want, however, is the one for the compression stroke, which also happens to be the one that's ignited by the spark plug (see where this is going?).
If you noted the position of the terminal for the number one spark plug wire on the distributor cap, then all that's left to do is mark the distributor cover directly under the terminal for number one (like we did here). Turn the crank until the distributor rotor is pointing directly at the mark for number one (in this photo it's off by a hair). This should be TDC for the number one cylinder. Once the crank pulley is off you can also check TDC by lining up the notch on the crank sprocket with the arrow cast into the oil pump.
[9] Time to break loose that crank bolt. Usually we'd remove the flywheel inspection cover on the under side of the motor to get at the flywheel and hold it in place, but just to illustrate that there's more than one way to do this we decided to pull off the starter instead and wedge a screwdriver in between the flywheel and the bell housing.
[10]
[10-11] Once the engine is prevented from turning (via the wedged screwdriver in the flywheel trick), the crank bolt is unscrewed, which takes a great deal of force, we might add. The crank pulley can be removed at this point. It uses a Woodruff key, so make sure not to lose the little bugger.
[12] With the pulley out of the way we can remove the lower timing belt cover. We notice this D16Y7 uses a crank trigger and pickup, which generates a signal that informs the ECU of crank position and provides more accurate timing, whereas previous-gen single-cam Civics generally do not use the trigger and pickup. We also check out the TDC notch on the crank sprocket (arrow).
[13] The end is near! We loosen the timing belt tensioner pulley bolt (that blue one) and this gives the belt enough slack so we can take it off.
[14] We visually compare the two belts. If you plan on reusing a belt you should definitely look for wear, cracks, splits, fraying, or oil contamination. It should be noted, though, that it's common practice to replace the timing belt with a new one every time it's removed, unless the old one is in new condition. The old belt (right), while not too bad, does appear to have plenty of miles on it. We'll go with the new Honda issue.
[15] When installing the timing belt we make sure the "UP" mark on the camshaft sprocket is at the top and the timing mark on the crank sprocket is aligned with the arrow on the oil pump. After we're sure everything is lined up properly we install the belt.
Now there are two schools of thought on creating tension in the belt. Some say that with a slight amount of tension in the belt between the cam and crank sprockets and with the tensioner bolt loose, you can slowly rotate the crank counterclockwise for a distance of three teeth on the cam gear and this should put tension on the belt, at which point the tensioner bolt can be tightened. We did it differently though, basically just leveraging a screwdriver on the block and pushing the pulley up until there was a fair amount of tension in the belt. Then we tightened the tensioner bolt. Seemed to work for us, but you decide what works best for you.
Just a couple of remaining considerations: We turned the crank a couple of revolutions and rechecked the timing marks for proper alignment. We also checked to see if the crank was binding or appearing to hit anything; this could be an indication that the valves are hitting the pistons. If this is the case, your timing is all screwed up. You should remove the belt and repeat the install, making sure all the marks are lined up correctly.
With the belt on we reinstalled everything in the reverse order of removal. We then ran the engine to check for correct operation.
( From HondaTuning http://www.hondatuningmagazine.com/tech/0406ht_timing/ )
Keeping Time
In our never-ending quest to help you maintain your whip, and save a buck in the process, we bring you a step-by-step on how to change a timing belt on the D series.
It's that toothed belt on the engine that the crankshaft uses to drive the camshaft(s), and while many of us never actually see it, most know it's pretty vital to the proper operation of the engine. We speak of course about the timing belt, and when it comes to replacing or even inspecting it, folks generally defer to anexpert. The only prolem is deferring to said expert can often exceed $250, a sizable sum if you're still in school or just working part time.
Because we have nothing but love for ALL of our readers, not just the rich one, we thought we'd show you how it's done. Or at least how it;s done on fifth and sixth gen single cam non VTEC D-series motors. Our M.E. extraordinare let us use his '99 Civic DX hatchback as the test subject, seeing that it already had 102,000 miles on it and the service manual recommends the belt be changed at 105k, and the entire process took us six hours, so it's definitely a weekend job. We also recommen that ou repace the tensioner and water pump while you're at it. And finally, despite what you may have seen or heard, you don't have to pull he engine. Perhaps more convenient, but not neccessary.
[1] We kick things off by raising the car and putting it up on jackstands. It's also necessary to remove the driver's side wheel and this long piece of useless plastic shielding underneath the front of the car for easier access to the crankshaft bolt.
[2] The spark plugs are removed, as are the plug cables. It's important to note the position of the terminals for all the plugs on the distributor cap; mess this up and your timing is completely fu**ed. Most terminals aren't marked, so follow the plug wire from the cylinder to the cap and remember which one goes where; the number one cylinder is normally the furthest to the right as you're facing the engine from the front of the car.
[3] Next, the valve cover comes off to access the plastic timing belt cover. The valve cover is typically secured with a handful of bolts.
[4] The drive belts are our next targets. For the power steering pump belt, loosen the pivot bolt (pictured) and pinch bolt underneath, then swing the pump out until the belt is loose enough to remove. For the alternator belt, the pivot bolt is underneath the alternator while the pinch bolt can be loosened from up top. Again, swing the alternator out until the belt is loose enough to remove.
[5] We have to unbolt the driver's side engine mount, but before we can we'll need to support the motor with a jack. A block of wood goes between the jack pad and the oil pan to avoid damaging the pan.
[6] Confident that the engine is safe, we remove
[7] Enough pieces are out of the way so we can easily remove the upper timing belt cover, so we unbolt it and take it out of the way.
[8] This next step is another critical one: setting the number one cylinder to top dead center (from here on out, TDC). Basically we need to turn the crankshaft with a socket and ratchet attached to the crank bolt until the number one piston is at TDC. Since this is a four-stroke engine, we know technically there are two TDCs, one for the compression stroke and one for the exhaust stroke. The one we want, however, is the one for the compression stroke, which also happens to be the one that's ignited by the spark plug (see where this is going?).
If you noted the position of the terminal for the number one spark plug wire on the distributor cap, then all that's left to do is mark the distributor cover directly under the terminal for number one (like we did here). Turn the crank until the distributor rotor is pointing directly at the mark for number one (in this photo it's off by a hair). This should be TDC for the number one cylinder. Once the crank pulley is off you can also check TDC by lining up the notch on the crank sprocket with the arrow cast into the oil pump.
[9] Time to break loose that crank bolt. Usually we'd remove the flywheel inspection cover on the under side of the motor to get at the flywheel and hold it in place, but just to illustrate that there's more than one way to do this we decided to pull off the starter instead and wedge a screwdriver in between the flywheel and the bell housing.
[10]
[10-11] Once the engine is prevented from turning (via the wedged screwdriver in the flywheel trick), the crank bolt is unscrewed, which takes a great deal of force, we might add. The crank pulley can be removed at this point. It uses a Woodruff key, so make sure not to lose the little bugger.
[12] With the pulley out of the way we can remove the lower timing belt cover. We notice this D16Y7 uses a crank trigger and pickup, which generates a signal that informs the ECU of crank position and provides more accurate timing, whereas previous-gen single-cam Civics generally do not use the trigger and pickup. We also check out the TDC notch on the crank sprocket (arrow).
[13] The end is near! We loosen the timing belt tensioner pulley bolt (that blue one) and this gives the belt enough slack so we can take it off.
[14] We visually compare the two belts. If you plan on reusing a belt you should definitely look for wear, cracks, splits, fraying, or oil contamination. It should be noted, though, that it's common practice to replace the timing belt with a new one every time it's removed, unless the old one is in new condition. The old belt (right), while not too bad, does appear to have plenty of miles on it. We'll go with the new Honda issue.
[15] When installing the timing belt we make sure the "UP" mark on the camshaft sprocket is at the top and the timing mark on the crank sprocket is aligned with the arrow on the oil pump. After we're sure everything is lined up properly we install the belt.
Now there are two schools of thought on creating tension in the belt. Some say that with a slight amount of tension in the belt between the cam and crank sprockets and with the tensioner bolt loose, you can slowly rotate the crank counterclockwise for a distance of three teeth on the cam gear and this should put tension on the belt, at which point the tensioner bolt can be tightened. We did it differently though, basically just leveraging a screwdriver on the block and pushing the pulley up until there was a fair amount of tension in the belt. Then we tightened the tensioner bolt. Seemed to work for us, but you decide what works best for you.
Just a couple of remaining considerations: We turned the crank a couple of revolutions and rechecked the timing marks for proper alignment. We also checked to see if the crank was binding or appearing to hit anything; this could be an indication that the valves are hitting the pistons. If this is the case, your timing is all screwed up. You should remove the belt and repeat the install, making sure all the marks are lined up correctly.
With the belt on we reinstalled everything in the reverse order of removal. We then ran the engine to check for correct operation.
( From HondaTuning http://www.hondatuningmagazine.com/tech/0406ht_timing/ )
