NST Pulley - Installed and Reviewed! (Crank bolt removal tip inside!)
 

I would say I recently installed my NST Pulley kit, but that would be misleading, since I installed them about 3 months ago. :icon18:

Anyway, I thought I would get around to some quick thoughts on the installation, and my personal review of the kit. Unfortunately this time around, I don't have too many pictures!

Here is a link to the kit if anyone needs it:

NST - The Leader In Nissan 370Z Pulley Development

I purchased a kit from a forum member, that was brand new, never used. I had the underdrive crank pulley, overdrive alternator pulley, and the shorter Gates belt.

Pulley Removal and Installation:

I began my install by jacking the car up on all 4 corners, and removing the the black plastic splash guard. I then promptly began draining the radiator, since I planned on removing the radiator hoses for maximum room to work with. The radiator has a drain plug that allows easy draining.

I then went topside, and removed the radiator overflow bottle, and the two radiator hoses, both top and bottom.

Then for removing the fans, the are only 3 bolts if I recall correctly that hold the top of the fans in place. The bottom has two legs that are seated in holes - just lift the fans and move them away from the holes. There is also a ribbon of connectors on top of the fans that you need to disconnect, or cut away since they have zip ties holding them.

Remove the fan by going UNDER the car - the top has no space.


After removing the fans, you have this much space:

http://i248.photobucket.com/albums/g...pse9364ddf.jpg

Once the fans are out, remove the serpentine belt from the car. The tensioner has a groove that you can place a rod in so you can lock it in place, like so:

http://i248.photobucket.com/albums/g...psd00d250b.jpg

Now, for the tricky part...removing the crankshaft bolt.

I'm not gonna lie. The bolt on my car was STUCK. HARD. At one point, I was debating removing my AC condenser and radiator, just to get an impact on the bolt. Luckily, I found a way.

Here's how I removed the crankshaft bolt from our cars.

http://i248.photobucket.com/albums/g...psfbc932c9.jpg

This looks a little confusing, but it is the spare tire iron, stuck in the U-joint of the driveshaft, closest to the transmission. I put the car in 3rd gear, and wedged the tire iron against the metal frame of the car:

http://i248.photobucket.com/albums/g...ps3f5eb0d2.jpg

The head of the iron is firmly planted against the frame of the car in this picture. It is not touching anything else but the frame.

With the engine effectively seized, I could now tackle the crankshaft bolt. I took a breaker bar, deep socket, and a 4 foot water pipe I had laying around, and attacked it from the top. Me and a friend pulled so hard, that the rear wheels started to lift due to the slack being lost in the driveline!

But, after much muscle, the bolt went loose, and a satisfying sigh was let out. From there, I proceeded with the rest of the install, using a tiny jaw puller from autozone (someone's journal had this trick in there, forgot who though.), and removed the crank pulley with no hassle. The stock pulley weighs a ton!

The alternator was next. I removed the alternator completely from the car - 3 bolts if I recall held it in place. I disconnected the leads, and as I tried to remove it from the car, I realized I would have to remove the swaybar to get it out from the engine bay. I went the lazy route, and just had the alternator sit on the swaybar:

(Took picture after installing the pulley, haha.)


http://i248.photobucket.com/albums/g...ps031f72d0.jpg

I took an impact gun to the bolt, and it came off right away. I reversed my removal of the alternator at this point.

For the NST crank pulley, mine was a tight fit. I sanded down the interior edges a bit, and it was a tiny bit smoother. I put the pulley on the crank snout as best I could, then used the crank bolt to seat it the rest of the way. Torqued it back down hard as well.

After this, it was super smoothing sailing. Just reverse everything you did, with the shorter belt, install the fans, hoses, and overflow bottle, and refill the radiator.

Review:

Overall, I felt little to no butt dyno difference. The car does rev faster, however, albeit a small amount. The SRM responds slightly quicker, and just tapping the gas in neutral makes it jump a little higher. It's nothing like a lightweight flywheel, but it's something! Powerwise, I'd say it's had an effect on my car, but that's something for a dyno to prove. :tup:

The installation was honestly not difficult, once I figured out the tricks. I'm a self taught shade-tree kinda guy, and it's nothing too crazy if you have the right tools.

I also have driven 4k miles, with not a single mishap or sign of trouble. I checked the bolts after doing my oil recently, and they are tight as a drum. Both pullies are seated nice and firm.

:tiphat:

Nice write up! Thanks for the advice.

I'm onto night #2 of my pulley install.
First night was pretty fruitless. Bolt stuck on hard. Tried penetrating lubricant and jolting the starter but i must've chickened out & let go of the clutch too soon because our cars don't have a mechanical ignition switch.

Tonight i managed to crack it loose... too loose in fact! I also had another go at using a cheater pipe on the breaker bar but no luck. Back to the dodgy trick. After 3 more jolt attempts, the latter 2 which lifted the front of the car a bit, the engine started!!!
Oil spattered around the front of the engine and underneath. Not a pretty sight but i've done my best to clean it all up.

If anyone knows where the ignition fuse is, they should reply here to save someone the mess i made. I found a fuse labelled IGN SW but wasnt sure
so i left it in. In hindsight, i should've played safe and taken that fuse out.

Removing the fans makes it a lot easier as you have more working space. Im not a big guy and i still found the space to be cramped.

For anyone doing the starter jolt trick, you need to have the breaker bar floating in the air at least 2 inches from the floor/whatever you intend to use as the striking surface. This creates some momentum before the end of the bar strikes the floor. Having it butted snug against the floor didnt work for me. Battery is in good condition too and had the belt already removed.

Only use a 6pt socket for this, preferably an impact socket.
My crank pulley didnt put up much of a fight. i didnt even need the puller. maybe when the engine started, it spun loose..

As for the alternator... what a bitch to remove!!
3 bolts - 1x tight 14mm long one (upper), 1x 12mm long one & a short 12mm one. The 12mm ones are easy to crack. 14mm bolt needed some muscling with the breaker bar & deep impact socket.

Then there is the 3 wire electrical connector, followed by the +12V lead
secured by a 12mm nut in a very cramped space.

Finally, 2x 8mm screws/bolts holding the loom bracket to the rear of the alternator. then wiggle the alternator free. be careful when it discovers freedom.. dont want to slice open any hoses or rip any looms!

Lowering the swaybar isnt hard. Just 4x 14mm nuts :) best to lower it before you wiggle the alternator free. having the alternator resting as described above, then drop onto your foot/leg/crotch when the sway bat swings free is not fun.

Removing the pulley required some penetrating lube and a rattle gun. My little 10.8V one got it loose after a few goes so those with larger more capable guns will have no problem. Use a 6pt socket (24mm or 15/16 size). The nut is quite soft and shallow so you definitely dont want to munch thru it.

I was unable to get a good enough grip using the belt and hand method to tighten the nut to the specified 118Nm using a torque wrench. I'm just going to rattle it on for a good while and call it done.

Hope this helps someone in the future.

According to the shop manual, we are supposed to torque the crankshaft bolt to 30 ftlbs then tighten an additional 90 degrees.

Even with the aid of a floor jack I was only able to tighten the bolt about 65 degrees. At that point, my breaker bar was bending a startling amount and the bolt was not getting any tighter. Think that is enough? I'm afraid that trying to tighten it more will break something honestly.

The fact taht it says 30ft lbs and then turn an additional 90 degrees means the bolt is probably a torque to yield and should be replaced. It would also explain why you were unable to get it to go 90 degrees as the bolt would have already been stretched so to speak. Doubt you will have any issues with it tho.

it's not actually specified as a single use item in the service manual, which is odd. mine hasn't loosened. I put a paint mark on the bolt head and the pulley and check it every oil change

Thanks guys. I actually did replace the bolt with a new one. I figured $6 was cheap peace of mind. Maybe I'll try to re-torque after a few heat cycles and see if it budges.

On another note, my oem crank pulley looks to have been balanced from the factory. They drilled out some spots of the outer ring. Do you think they were just balancing the pulley itself or is this to balance the whole crankshaft? I always thought the crankshaft was balanced internally on modern vehicles and didn't require pulley balancing to compensate...

http://i1238.photobucket.com/albums/...ps1c4b2377.jpg

i cant remember if the threads are meant to be lubricated or fitted dry but if it doesnt specify lubing the threads, i'd recommend spraying the end of the crankshaft (where the bolt goes into) with brake cleaner, then blast it dry with shop air and then install the bolt. Sometimes the threads are dirty or unneccessary oil gets pushed into the end as the bolt is driven in. The pressure has to go somewhere.

Anything that rotates should be balanced. The crank is internally balanced but if you slap a heavy pulley on the end which isnt balanced then it's going to upset things

How much smaller of a belt do I need? I just ordered the NST alternator / crank kit. Their website stated the stock belt should work unless it's wore out then it would need to be replaced.

nah even with a brand new OEM belt it is too long. I am using a 7PK2000 and it's still slightly too long but it's been running fine for almost a year now. OEM is 7PK2020 from memory

Thank you but which is the correct size then if your 7PK2000 is slightly too long. Their website shows a "Gates Belt K070786" but I work at a auto distributing company. We don't carry gates belts. Only their water pumps. We have dayco belts like the 7PK200 you have. And motorcraft belts I can get it basically for free if I find the same size as the "K070786" but in dayco or motor craft.

dont take my word for it but if i was to do it again, i'd try a 7PK1990.
7PK - number of ribs
1990 - the circumference in millimetres

the aim is to line up the marks on the auto tensioner (refer to service manual) and unless my 7PK2000 is actually longer than it should be, i doubt a 7PK2010/K070786 would bring it into spec since it's longer. good luck man

Thanks for schooling me on that!! I didn't even know that. I've never had to deal with belts except OEM replacement. Never done anything super charged or anything I'd have to guess sizes on. So you're saying the K070786 is longer than your 7PK2000?

Because the Gates K070786 is "Outside Circumference (in.)
79.183" so in mm it'd be 2011mm and yours is 2000mm? So 7PK1990 belt would be ideal?

Here i was reading and thinking, well the vq37vhr is a high rev and high vibrational engine where the front of the engine the crankshaft vibrates the most, nissan comprehend the vibrations by equipping heavy flywheel and a heavy pulley, dont u guys think that in the long run due to lighter pulley would break down the bearings, basically diminishing life?

Yep, K070786 cross references to a 7PK2010. You can do cross reference checks on autopartoo.com or the belt manufacturers' websites usually have a cross ref search area. You can even put in OEM part numbers on some sites. The Bando site lists the wrong belt for our Z. I've emailed them but they didnt respond so dont follow the Bando site if anyone is searching for an OEM belt. Oddly enough, Bando makes the belts for Nissan...

I am just speculating that a 1990mm circumference belt will make the tensioner marks line up perfectly so feel free to try it and report back. Check to see if the store does no-fuss exchanges before purchasing :) otherwise, 7PK2000 is what i've had on for over a year now with no issues.

As for the vibration issues, well let's just say it's a debatable topic. I've had the pulley for over a year now and engine still feels smooth. 3 oil changes and there has only been a tiny bit of metal powder on the magnetic plug but i am yet to do any UOA. To conclude, there's a risk with everything so weigh it up and make your own educated decisions :)

Well man we got 7pk1990 belts as well as 2000 and 2010 so it's all good. I'll just use a 7pk2000 and bring a 7pk1990 to try first. And I will report back after install. If not 7pk2000 it is!! And as far as the tiny bit of metal powder do you really think it's coming from the crank bearings?

hard to tell without a used oil analysis..

Man you are blessed to have all those options in front of you ;) no excuse to not try haha good luck with it

Is there a way to tell truly if it is from crank bearings or another source? If I happen to install the pulleys and find any type of metal powder how would I test to know its for sure coming from the crank bearings? Just curious.

One more question, I found a bando (Nissan OE brand) 7pk1995 belt. We also have a Dayco 7pk2000 belt. But no 1990. So should I go with 1995 it should be perfect. Not too much smaller than yours. But just right. Do you mind telling me what brand belt you have?

Mine is a Gates belt, made in EU. It's a Gates Horizon belt. Packaging looked dodgy and not like the micro V belts they sell locally here. But it's very good, has a grippy glossy back and a lot of late model BMWs use the same design Gates belts.

7PK1995 should be good man. Take them both home, fit the smaller one and see if the lines align ;) only one way to find out. And you cant tell a belt has been fitted as long as you work with clean hands so no one will find out haha

Okay sweet I will report back and quote you after install in a week or two and let you know if the 1995 belt fits better. So you'll know. :) thanks for your help man

I been hesitant to install this part, I've had it in a box since I received it.

I received mine today. Still have to wait on belt should be here Saturday or next Monday. I'm slightly hesitant. Only reason being because I've seen on here what "can" happen. But for the most part I haven't found anyone on here that's said "I installed NST pulley and it ruined my engine" or "well pulley voided my warranty and now I have a $30,000 paper weight." Nothing. Everything I'm seeing is moderate dyno proven hp/torque and no hesitant when pressing throttle. I did order a magnetic oil drain plug like mentioned above to monitor metal powders / shavings and will test if I ever come across any. And report back. I kinda scared myself too reading on here. But most people commenting "the crank pulley should be balanced it'll ruin engine" obviously don't know the engines in modern days are internally balanced so that shouldnt effect your crank. It's lighter so it's should be easier for the crank to move more freely. I would speculate that as long as it's properly seated that it should be fine. And haven't heard any proven engine ruin stories. But have heard/seen proven dyno sheets, and success stories for this. That's the only reason (( I AM )) moving forward with installing mod. But since I will be installing Ark Gt-S springs this weekend. I will probably not tackle both. I'll probably tackle pulleys the following weekend when I do my oil change. But will report back to let you know how it goes.

I have always had a bit of metal powder on my magnetic plug (since brand new in 2010) so I don't think you can really make a correlation there. You would need an oil analysis to look for elevated lead I believe.

That's what I figured. I checked mine today when I did my oil change and I had very fine powder on my magnetic oil plug... So I will check next time I change oil AFTER installing pulleys and if for some reason there's more or it's more noticeable. I will run an analysis on it.

When i just bought my car it had 160miles on it,(it was driven to me) the first thing i bought is the magnet that goes on ur oil filter, now after i have removed the filter on the next oil change. I rolled the filter on the floor and u can clearly see which side has all the metal stuck to it, also it weighted as if the whole filter was full of oil in it when i let it drain for over 10 min.

I think am gonna put that pulley on as well, se if more shavings get stuck on the magnet.

Am at 32k and last oil change there where barely any shavings at all, so we'll see.

I know, I know....reviving an old thread. I just wanted to say thanks to the OP for this DIY (reps given)! It helped me this past weekend when installing my NST lightweight crank and alternator pulleys.

A few notes:

- I followed these install instructions to a 'T'. I started by removing the plastic splash guard and draining the radiator. Only after doing so and moving to the top of the engine, did I realize that there is more than enough room between the hoses to get leverage to remove the crank pulley bolt. If you want to save a step, you don't have to drain the radiator. You can just drain the overflow bottle, remove it, and you'll have access to the radiator fan bolts. Or, you can do like I did, and remove the overflow bottle bolts, leave the radiator cap in place, and once you remove the hoses to the overflow bottle, just invert the overflow bottle, leave the fluid in there, and remove the bottle.

- I tried using an air ratchet to remove the crank pulley bolt, but that son of a b**** must have been put on there by the world's strongest man. I ended up using a breaker bar with about a 4 foot extension (as OP did).

-There is no need to remove the alternator to remove the alternator pulley and bolt. With the air ratchet, it came off fairly easily.

I just wanted to contribute to hopefully help others out in the future, as I thank everyone who came before me and wrote other DIYs which have helped me tremendously (including this one :tup:).

Thanks for the tips man, I have the crank and alt pulleys to put on and was going to wait since I had a fresh rad flush. If I don't have to then I'll probably do it this long weekend at some point.

having issues my crank pulley keeps spinning with the nut what do i do i have an automatic so do i still need to jam the transmission ujoint with a tire iron?

If it's in Park, you've already locked the output shaft. Trouble is, with the liquid coupling (torque converter), you have to lock the crankshaft. Can you get access to the starter ring? A big flat blade screw driver between two teeth and lodged against the trans case will provide that lock. It means you need a second pair of hands, though.

sorry i dont understand what u mean by starter ring im not good with the technical terms lol

Bolted to the rear of the crankshaft is the "flex plate". It has teeth on the outer ring that are engaged by the starter to turn the engine.

https://www.2carpros.com/images/arti...-plate-345.jpg

crank bolt removal video DIY: https://youtu.be/u4BJRmlw0Ak