'16 Pilot - Timing belt replacement questions

[parshisa]

Got everything for timing belt change tomorrow (aisin kit, new bolts for the idler and tensioner, new accessory belt, 2 gal of coolant). Couple of the question that I have:

1. I'm planning to replace the water pump, so should I drain the radiator and the block before removing the timing belt and water pump?
2. Does the engine need to be supported (with the jack/wooden block) at the oil pan before side mount removal? I'm seeing different opinions on that (although honda manual states it should be supported).
3. I'm planning to change the spark plugs as well, so should i remove them before the timing belt job to make it easier to spin the crank shaft? A bit hesitant to leave the cylinders exposed to the ambient.

Thanks everyone. Feel free to drop any other suggestions, would greatly appreciate it.

Edit: forgot to mention, got the 1/2" Fuel Milwaukee high torque impact gun (1,500 ft/lb) with a Leslie weighted socket, so hopefully it'll take care of the crank bolt

 

[The Critic]

1) Drain the radiator and prepare for the coolant water fall upon removing the water pump.
2) No
3) You can, but it isn't necessary.

 

[Nukeman7]

1. You only need to drain the radiator. Once the coolant level drops below the elevation of the water pump, you will be good to go. No need to drain the block itself.

2. Yes, you need to support the engine with a jack and wooden block before removing the side motor mount. Otherwise, it may bind and create alignment issues during reinstallation.

3. First thing you need to do is to break the tension on the crankshaft pulley bolt. Then, remove the spark plugs to facilitate easier alignment of the timing marks before going further.

4. Before you release the tension to remove the old belt, I highly suggest marking: (a) an arrow in the direction of rotation, and (b) unique index marks on two adjacent teeth on the belt and the corresponding tooth on both cam gears and the crank gear. I use different color paint markers for each gear/teeth. Once you remove the old belt, count the number of teeth between each index marks and transfer the paint markings and arrow to the new belt. Have another person count the teeth between the markings on each belt to independently verify the markings are identical on both belts. This indexing procedure will prevent you from mis-aligning the new belt if the gears rotate slightly while the belt is removed.

 

[parshisa]

1. You only need to drain the radiator. Once the coolant level drops below the elevation of the water pump, you will be good to go. No need to drain the block itself.

2. Yes, you need to support the engine with a jack and wooden block before removing the side motor mount. Otherwise, it may bind and create alignment issues during reinstallation.

3. First thing you need to do is to break the tension on the crankshaft pulley bolt. Then, remove the spark plugs to facilitate easier alignment of the timing marks before going further.

4. Before you release the tension to remove the old belt, I highly suggest marking: (a) an arrow in the direction of rotation, and (b) unique index marks on two adjacent teeth on the belt and the corresponding tooth on both cam gears and the crank gear. I use different color paint markers for each gear/teeth. Once you remove the old belt, count the number of teeth between each index marks and transfer the paint markings and arrow to the new belt. Have another person count the teeth between the markings on each belt to independently verify the markings are identical on both belts. This indexing procedure will prevent you from mis-aligning the new belt if the gears rotate slightly while the belt is removed.

Thank you for suggestions, couple of follow up questions.

1. Break the crank bolt loose first thing before removing the side mount, timing covers, etc? Once it loose, hand tighten it back and then proceed with removal of the covers, setting the timing etc?

2. Apply minimal tension at the oil pan with the jack just to prevent if from the downward motion when side mount is removed?

3. I’ve seen suggestions on marking the old timing belt and transferring the marks on to the new one. Although, I’m having a hard time understanding how it would help. It the cam gear shift forward/reverse during the belt removal/installation wouldn’t it be visible anyways with the mark on the sprocket and the block not lining up? How would the marks on the new belt be helpful in this scenario? Just trying to figure out what I’m missing here

 

[Nukeman7]

Thank you for suggestions, couple of follow up questions.

1. Break the crank bolt loose first thing before removing the side mount, timing covers, etc? Once it loose, hand tighten it back and then proceed with removal of the covers, setting the timing etc?

Yes, the hardest part of this job is loosening the infamous crank bolt. It should not be too difficult if you have the weighted socket and a decent impact wrench.

2. Apply minimal tension at the oil pan with the jack just to prevent if from the downward motion when side mount is removed?

Yes, just enough to keep the engine from sagging and binding up the motor mount bolt.

3. I’ve seen suggestions on marking the old timing belt and transferring the marks on to the new one. Although, I’m having a hard time understanding how it would help. It the cam gear shift forward/reverse during the belt removal/installation wouldn’t it be visible anyways with the mark on the sprocket and the block not lining up? How would the marks on the new belt be helpful in this scenario? Just trying to figure out what I’m missing here

The cam sprockets are under a bit of torsional tension due to the force of the valve springs. I think the FSM says to insert the threaded end of battery hold down J-bolts into a hole in the back part of each head to keep them from turning, but I have found that the cam sprockets can still rotate ~1/2 a tooth in either direction. If each cam sprocket rotates 1/2 tooth in opposite directions, the timing belt alignment will be off by one tooth. Index marks can help prevent this mistake, especially since the old Gates/Unitta belt will be slightly stretched/worn compared to the new Mitsuboshi belt.

 

[ctechbob]

Thank you for suggestions, couple of follow up questions.

1. Break the crank bolt loose first thing before removing the side mount, timing covers, etc? Once it loose, hand tighten it back and then proceed with removal of the covers, setting the timing etc?

2. Apply minimal tension at the oil pan with the jack just to prevent if from the downward motion when side mount is removed?

3. I’ve seen suggestions on marking the old timing belt and transferring the marks on to the new one. Although, I’m having a hard time understanding how it would help. It the cam gear shift forward/reverse during the belt removal/installation wouldn’t it be visible anyways with the mark on the sprocket and the block not lining up? How would the marks on the new belt be helpful in this scenario? Just trying to figure out what I’m missing here

Yes to #1. As a matter of fact, I would do it the day before to make sure you can get it off. These crank bolts are notorious for being tighter than tight over time (and by that I mean 10 seconds after it is installed). If you have a good 1/2" impact you can use one of the weighted sockets which usually does the trick.

 

[parshisa]

Yes, the hardest part of this job is loosening the infamous crank bolt. It should not be too difficult if you have the weighted socket and a decent impact wrench.

Yes, just enough to keep the engine from sagging and binding up the motor mount bolt.

The cam sprockets are under a bit of torsional tension due to the force of the valve springs. I think the FSM says to insert the threaded end of battery hold down J-bolts into a hole in the back part of each head to keep them from turning, but I have found that the cam sprockets can still rotate ~1/2 a tooth in either direction. If each cam sprocket rotates 1/2 tooth in opposite directions, the timing belt alignment will be off by one tooth. Index marks can help prevent this mistake, especially since the old belt will be slightly stretched/worn compared to the new belt.

Makes sense. Much appreciate you sharing the knowledge!

 

[parshisa]

Yes to #1. As a matter of fact, I would do it the day before to make sure you can get it off. These crank bolts are notorious for being tighter than tight over time (and by that I mean 10 seconds after it is installed). If you have a good 1/2" impact you can use one of the weighted sockets which usually does the trick.

Ugh..my stomach is already turning just thinking about it. I plan on starting the job tomorrow after dropping the kids off at the school. Car up, wheel off, and here comes my dandy impact with the Leslie socket…excited to see what it can/can’t do. Will let you know

 

[The Critic]

The cam sprockets are under a bit of torsional tension due to the force of the valve springs. I think the FSM says to insert the threaded end of battery hold down J-bolts into a hole in the back part of each head to keep them from turning, but I have found that the cam sprockets can still rotate ~1/2 a tooth in either direction. If each cam sprocket rotates 1/2 tooth in opposite directions, the timing belt alignment will be off by one tooth. Index marks can help prevent this mistake, especially since the old Gates/Unitta belt will be slightly stretched/worn compared to the new Mitsuboshi belt.

The marks are pretty easy to see. Just turn the crank until the “1” appears in the upper timing cover window.

 

[Nukeman7]

Ugh..my stomach is already turning just thinking about it. I plan on starting the job tomorrow after dropping the kids off at the school. Car up, wheel off, and here comes my dandy impact with the Leslie socket…excited to see what it can/can’t do. Will let you know

The 19mm Lisle weighted socket is the bomb! I have NEVER failed to remove a Honda crank bolt just by using it with my DeWalt battery powered XR impact wrench. No worries...it will come off with that socket...I don't even have to use the Honda crank pulley holder tool when using the weighted socket. Word to the wise, do NOT use the Lisle socket to install the bolt.

 

[The Critic]

Word to the wise, do NOT use the Lisle socket to install the bolt.

Why not? I do it every time. Just do a light touch…

 

[parshisa]

Why not? I do it every time. Just do a light touch…

I’m sure you having done a few dozens of these know what the little touch is…unfortunately I don’t. So hand tight, torque wrench and then pesky 60 deg..if I can get it

 

[TomYoung]

1) Drain the radiator and prepare for the coolant water fall upon removing the water pump.
2) No
3) You can, but it isn't necessary.

Removing the plugs first and replacing last makes this job quite a bit easier. I would add that it is well work marking the pulleys, old belt and new belt with white out, as a failsafe on getting the new belt installed. Also, you should invest in the crankshaft socket an a breaker bar that is at least a quarter of a mile long.

 

[TomYoung]

Ugh..my stomach is already turning just thinking about it. I plan on starting the job tomorrow after dropping the kids off at the school. Car up, wheel off, and here comes my dandy impact with the Leslie socket…excited to see what it can/can’t do. Will let you know

Don’t be afraid, but make sure you give yourself more than a day to do this.

 

[TomYoung]

Thank you for suggestions, couple of follow up questions.

1. Break the crank bolt loose first thing before removing the side mount, timing covers, etc? Once it loose, hand tighten it back and then proceed with removal of the covers, setting the timing etc?

2. Apply minimal tension at the oil pan with the jack just to prevent if from the downward motion when side mount is removed?

3. I’ve seen suggestions on marking the old timing belt and transferring the marks on to the new one. Although, I’m having a hard time understanding how it would help. It the cam gear shift forward/reverse during the belt removal/installation wouldn’t it be visible anyways with the mark on the sprocket and the block not lining up? How would the marks on the new belt be helpful in this scenario? Just trying to figure out what I’m missing here

You are marking the belts and the gears.

 

[parshisa]

Removing the plugs first and replacing last makes this job quite a bit easier. I would add that it is well work marking the pulleys, old belt and new belt with white out, as a failsafe on getting the new belt installed. Also, you should invest in the crankshaft socket an a breaker bar that is at least a quarter of a mile long.

I’ve got these two ready to go if needed. Breaker bar is not quite a quarter of a mile long, but better than nothing I suppose

 

[parshisa]

Don’t be afraid, but make sure you give yourself more than a day to do this.

I’m off work for another 3 weeks or more, so yeah, plenty of time on hand. How long did it take you to get the first one done?

 

[The Critic]

I’m sure you having done a few dozens of these know what the little touch is…unfortunately I don’t. So hand tight, torque wrench and then pesky 60 deg..if I can get it

Hardest part of the job is getting the new timing belt on. If you haven’t done one before, understand the difference between the tension side and the slack side.

Also, there is no need to grind down the battery j-hook for tensioner removal.

Lastly, the pin that comes with the aisin hydraulic tensioner is very flimsy. Use a pair of side cutters to carefully “walk” the pin out.

 

[Number_35]

4. Before you release the tension to remove the old belt, I highly suggest marking: (a) an arrow in the direction of rotation, and (b) unique index marks on two adjacent teeth on the belt and the corresponding tooth on both cam gears and the crank gear. I use different color paint markers for each gear/teeth. Once you remove the old belt, count the number of teeth between each index marks and transfer the paint markings and arrow to the new belt. Have another person count the teeth between the markings on each belt to independently verify the markings are identical on both belts. This indexing procedure will prevent you from mis-aligning the new belt if the gears rotate slightly while the belt is removed.

Marking the old belt (I like a yellow paint pen) while it's still installed, and then transferring the marks to the new belt before installation, is an excellent idea. Highly recommended!

I haven't done a Honda TB in a long time, but this has worked very well for me on several Mazdas and a Mitsubishi.

 

[TomYoung]

I’m off work for another 3 weeks or more, so yeah, plenty of time on hand. How long did it take you to get the first one done?

Two fairly long days (18 hours). A few HFT runs in the mix.