Cambelt Replacement

[michaux]

Hi from New Zealand.
I know this has been covered many times, but can I be pointed to a comprehensive article on procedure to replace the cambelt.
I also need to buy the parts and would appreciate good contacts.
As the water pump was replaced 15,000km ago, I am not planning to replace that.
While I am at it, I also plan to check/adjust valve clearances. Is there a special tool needed, or can one adapt something?
Thanks in advance
Kind Regards
Frank

 

[JohnWayne]

Check out "Lap of the World" on youtube. Richard just put together a pretty good video series on T belt.

 

[Honcho]

Hi from New Zealand.
I know this has been covered many times, but can I be pointed to a comprehensive article on procedure to replace the cambelt.
I also need to buy the parts and would appreciate good contacts.
As the water pump was replaced 15,000km ago, I am not planning to replace that.
While I am at it, I also plan to check/adjust valve clearances. Is there a special tool needed, or can one adapt something?
Thanks in advance
Kind Regards
Frank

Hi Frank-

You've come to the right place. I would order the parts from either MITA Motorsports or Amayama in Japan. MITA's website is down for maintenance, but both vendors are top-notch for the NSX.
You should refer to this link for the TB/WP procedure and use it in connection with the factory service manual procedure:
https://www.nsxprime.com/FAQ/DIY/timing-belt.pdf

Here is my TB/WP parts list. Keep in mind, this is for a 91-94 US Acura NSX. The parts may be different for your car and you should confirm with the vendor.

Honda Timing Belt (JDM) 1 06141-PR7-305
Timing Belt Adjuster 1 14510-PR7-A01
Valve Cover Gasket Set 2 12030-PR7-010
Water Pump Assy. 1 19200-PR7-305
Water Pump Bolts (special) 2 90049-PH7-000
Water Pump Bolts (special) 7 90052-PH7-000
Water Pump Dowels 2 94301-06100
Crush Washer 8mm 2 90471-580-000
Tensioner Bolt 1 90016-P0G-A00
Tensioner Bolt Washer 1 90031-PV0-305
Crank Pulley Bolt 1 90019-PR7-A01
Crank Pulley Key 1 90704-PH7-000
Crank Pulley (MT) 1 13811-PR7-A02
Tensioner Bolt Rubber 1 90401-634-000
Adjuster Spring 1 14516-PR7-A00
Oil Cooler Pedestal Special Bolts 2 90042-PR7-A00
Dipstick O-ring 1 91302-GE0-000
Oil Pump Gasket (Fig 8) 1 91318-PY3-000
Oil Filter 2 15400-PL2-315
Mobil One 0W-40 (5qt) 1
Mobil One 0W-40 (1qt) 1

Since you're going to be taking the engine apart partially, it is also a good time to perform the engine refresh service if it has never been done before. It's a few hundred dollars worth of additional parts, but your access will never be as good as it is now and your NSX will be sorted for at least another 10 years. Here are the parts you should replace:

Cam Plug 4 12513-PR7-A00
Rear Main Seal 1 91214-PL2-003
Oil Pan Gasket 1 11251-PH7-000
Cyl Head Dowel o-ring x2 2 91302-GE0-000
Oil Pump Seal 1 91212-PR7-A01
Spool Valve Solenoid O-Ring x2 2 36172-PR3-005
Spool Valve O-Ring x2 2 15825-PR3-005
Spool Valve Mount Bolts 6 95701-06030-08
Spool Valve Top Bolts x6 6 95701-06018-08
Oil Pressure Sensor O-Ring 1 91319-PR3-003
Camshaft seals 4 91213-PR7-A01
Water Passage O-Ring x 2 2 91313-PR7-A00
Water Pipe O-Ring x2 2 91314-PR7-A00
LMA Set 12 14820-PCB-305
Alternator Belt 1 31110-PR7-A01
Spark Plug x6 6 98079-5614H
A/C Belt 1 38920-PR7-A01
Oil Cooler O-ring 1 91316-PE7-730
Oil Cooler Bolt O-ring 1 91327-PH7-003
PCV Valve 1 17130-PR7-A01
Rocker Shaft Washers 8 12209-PR3-000
Rocker Shaft Bolts 8 12208-PR3-000
Rocker Shaft Orifice O-Rings 4 91306-PJ4-000
Block Coolant Plug O-Ring 1 91301-PR7-A00
Exhaust Manifold Studs 14 90026-PV0-000
Exhaust Manifold Nuts (NA2) 14 90217-657-000
Exhaust Manifold Gasket (NA2) 2 18115-PBY-J02
Coolant temp sensor (TW) 1 37870-PJ7-003
Hondabond HT 2 08718-0004
Block Drain Washers 2 90481-463-000
Crank Cyl Sensor (AYA) 1 37840-PR7-A03
Rear Coil Cover Gasket 1 12521-PR7-A00
Front Coil Cover Gasket 1 12511-PR7-A00
Oil Pan Pickup O-ring 1 91312-PR7-A00
Rear Main Seal Bolts 7 90052-PH7-000
Intake Manifold Studs 4 92900-080-400B
Alternator Grommet 1 31120-PR7-A00

If possible, I recommend removing the engine for this procedure. Limited access and visibility while the engine is in the car means a higher likelihood of making a mistake or missing something. Also, jobs like the valve adjustment and fitting the rear head cover without pinching the gasket are much, much easier. You will need a 3/4" impact gun to break the crank pulley nut, or about a 6-foot long pipe and sturdy breaker bar, along with a crank pulley holder. For the valve adjustment, you'll need this tool: https://www.amazon.com/Powerbuilt-10mm-Valve-Adjusting-Honda/dp/B073WH1DBZ/ref=sr_1_1?dchild=1&keywords=10mm+valve+adjustment+tool&qid=1617376446&sr=8-1 If you're doing the job in the car, you'll need to cut down the screwdriver handle so it can fit in the rear bank. [MENTION=12494]R13[/MENTION] has a good demonstration in his YouTube video.

Hope this helps. I'll add the lists once I'm back home and can grab them from the computer.

 

[Old Guy]

Being in New Zealand, probably the most comprehensive source for OEM parts is Amayama.com or JP-CarParts.com. I use Amayama as the source for most of my parts. When you do a parts search on Amayama, see if the EMS shipping option is available. Because of Covid restrictions, shipping options are restricted and Japan Post / EMS is no longer available to a lot of locations. If EMS is not available the alternative is courier services and they are pretty pricey. The costs savings associated withusing EMS are significant for larger packages. If you can wait until Covid subsides and shipping options return to normal you may save a significant amount of money if you can use the EMS option.

There is a special Honda tool for adjusting the valve clearance which makes the job easier. It is not 100% necessary. It sort of looks like this thing.

Powerbuilt Tools 648827 Powerbuilt 10mm Honda® Jam Nut Valve Tool | Summit Racing

But, the Honda tool has a much lower profile. My Son has the Powerbuilt tool for adjusting the valves on the K20 in his RSX. Because of the length of the tool it won't fit between the valve adjuster and the firewall. It might fit if you sawed off the top 5-6 cm of the screwdriver part of the handle. If you Google Honda Valve Adjustment Tool you can find information on making your own version of the tool.

There is at least one link in the Prime Wiki to doing the timing belt job and there are a number of threads on Prime discussing the job. If you go to Kaz's blog on the NSXCB forum I am sure you will be able to find lots of authoritative guidance on the cam belt change

NSXCB Forums - Recent Blogs Posts - Blogs

My only firm advice would be to get a service manual. If you search the Prime site you will find links that allow you to download a free .pdf version of both the early and late service manuals. They are not as good as a paper manual ( the late .pdf manual has some large gaps); but, they are free and better than routing around in the dark.

 

[tucsonsx]

Here is DIY engine lift support.

www.nsxprime.com/forum/showthread.php/153345-Engine-lift-support?highlight=tucsonsx

 

[tucsonsx]

Here is DIY engine lift support.

www.nsxprime.com/forum/showthread.php/153345-Engine-lift-support?highlight=tucsonsx

The main advantage of using a cradle is that all the weight is on the oil pan bolts so the gasket doesn’t get crushed.

 

[michaux]

Hi again,
As my water pump is 9 years old, but only 25,000km old (15,000 miles), I am not planning on replacing it.
Same for the crank cyl sensor.
Comments?
Thanks
Frank

 

[Old Guy]

My water pump is 21 years old, so based upon my experience you should be good for another 12 years. However, I will be replacing it when I do the TB this year otherwise I would be pushing it to 31 years which might be testing my luck. As an observation, water pump life is probably more a function of time and how often you change the coolant. If there is O2 in the coolant stuff corrodes even when the engine isn't running. Replace the coolant every 2-3 years and those fresh corrosion inhibitors will keep things looking good.

Replace the crank / cam position sensors - I would not bother. They are reluctance sensors - a coil of wire wound on a steel core. Pretty simple and durable. They are potted in an insulating compound which gets oozy with age and makes the sensor look like it is ready for the garbage can; but, I have never heard of one failing. Others can advise differently; but, I think there are better places to spend your preventative maintenance dollars

 

[Honcho]

Hi again,
As my water pump is 9 years old, but only 25,000km old (15,000 miles), I am not planning on replacing it.
Same for the crank cyl sensor.
Comments?
Thanks
Frank

My water pump is 21 years old, so based upon my experience you should be good for another 12 years. However, I will be replacing it when I do the TB this year otherwise I would be pushing it to 31 years which might be testing my luck. As an observation, water pump life is probably more a function of time and how often you change the coolant. If there is O2 in the coolant stuff corrodes even when the engine isn't running. Replace the coolant every 2-3 years and those fresh corrosion inhibitors will keep things looking good.

Replace the crank / cam position sensors - I would not bother. They are reluctance sensors - a coil of wire wound on a steel core. Pretty simple and durable. They are potted in an insulating compound which gets oozy with age and makes the sensor look like it is ready for the garbage can; but, I have never heard of one failing. Others can advise differently; but, I think there are better places to spend your preventative maintenance dollars

As long as your crank sensor potting has not melted out, you should be ok. Here is my crank sensor after 137,000 miles and 28 years of service. It needed to be replaced.

As for the water pump, lower miles and longer years (i.e., sitting for long periods of time between use) seems to be worse for the pumps than lots of miles. The bearings and impeller simply rot out from oxidation, as Old Guy points out above. Kaz has a few examples in his blog. With that said, you might be able to get away with it.

 

[goldNSX]

A little bit OT but I've read about Hondabond HT here. Can it be sourced in Japan?