I know that there has been a lot of talk recently about whether or not these pulleys can cause long term damage to the crank bearings, but for anyone who's willing to give these a try, here's one way to get the crank pulley installed. You don't have to jack up the car, and this will work for a G35 with 5AT.

1. Remove the plastic engine cover and the front middle air duct.

2. Remove the plastic undertrim under the engine. This is the piece with 2 metal support braces on it. For this, you have to crawl halfway underneath the front bumper, and remove about 10 10mm bolts. My arms were just long enough to reach the 2 bolts at the far end. Make sure you don't lose any of the bolts. Place the trim piece aside. I took time to clean it at this point.

3. Using a 24" breaker bar with 19mm socket driver, place the bar at the 5 oclock position (looking from the front bumper area) on the crank pulley bolt. The end of the breaker bar should be sitting on the ground or just above it. Crank the car a few times. Don't actually start the car. The car's engine will loosen the bolt for you. The breaker bar has to be long enough so that the end will touch the ground and not just spin around when you try and start the car. This will get the bolt off in about 30 seconds. If done right, you can unscrew the crank bolt with your bare hands.

4. Crawling back underneath the car (helps if the car is not lowered), find the 2 12mm bolts that are used for the belt tensioner pulleys. The bolts are pretty long, and you can see the bolt shaft extending upward into the mounts for the tensioner pulleys. Loosen these guys up, but don't actually remove them.

5. Then from above, you can loosen the 14 mm bolts holding the tensioner pulleys Once they are loose, you can remove the stock belts. Carefully remove the stock crank pulley by pulling straight out.

6. Place the new pulley onto the crank, making sure that the notch is lined up. It'll only go in one way.

7. Now you have to tighten the pulley. Unorthodox provides the specifications for how tight to go. The tough part is keeping the crank from moving while tightening. On a 6mt, you can probably have someone mash on the brakes in 6th gear. On the 5AT, I used 2 metal hose clamps to create a 2 link chain. Use hose clamps that are about 5 in in diameter. And they have to be metal, otherwise they won't hold. One hose clamp goes through one of the holes in the unorthodox pulley, I would use a hole at 6 oclock. The other hose clamp is linked to the first clamp and at the same time tied around the strut bar down at the bottom. Tighten the hose clamps to tighten your 2 link chain, and now you can start tightening the crank bolt. The hose clamps, if they're in good shape, will prevent the crank from spinning. I know you can also jam a crowbar through an access panel on the 5AT, but I couldn't find the panel. Using this method with hose clamps, they held the pulley in place while I tightened the bolt to over 100 ft lbs. I'm open to suggestions as to how else to hold the pulley in place on a 5AT.

7. Once the crank bolt is tightened, unscrew the hose clamps and put them aside. Now you can install the new belts and retighen the tensioners. I made note of how much deflection the stock belts would give with me pushing on them, so I tightened the tensioners to give the same amount of give. This gave pretty good results. No squealing, etc.

8. Start the car at this point, making sure everything is ok, no funny noises, etc. You may have to adjust the belt tensioners.

9. Then reinstall the bottom plastic engine trim, the air duct, and engine cover.

This can be done in half a morning. I even took time to clean everything while I had things apart.

I'm going back to the dyno this coming week. It's the same one I dynoed on last time, so hopefully there will be less confounding factors.

Feel free to let me know if I left some steps out, or if you have better ways to get this done. The toughest part if the pulley install is usually getting the crank bolt off, then retightening it to specs.

 

Great post - if I would have had these step-by-step instructions about a month ago, I probably would have went ahead and tried to install it myself... but I only spent $60 getting it installed, so it was worth it for me to not have to worry about running into any problems and having to take it somewhere else anyways...

PS - should be moved to DIY section after others have read...

2003.5 Brillant Silver G35 coupe 5AT
JDM Clear Corners, Alum. Pedals, Pro-1 Short Ram Intake, Helix SS Test Pipes, UR Crank Pulley, Custom Grounding Kit, CF Engine Cover, Kinetix Plenum (On Order)

 

great post, did you get your dyno results? I'd love to hear what the gain is...

 

Yeah, I went to the dyno, but the dyno was reading low. Really strange, and the guys at my350z.com are estimating that the dyno was reading 6% low.

Anyway, my previous PEAK HP and torque was 219.7/228.

This time it was 223.3/221. Again, the dyno was probably reading low. I'm not sure how I would be losing torque, and the entire curve from 3K to 5K was shifted downward with this new dyno plot.

The mods since the first dyno were Kinetix plenum, popcharger, and UR crank pulley.

 

I wish you would had taken some pictures. A picture is worth a million words when dealing with installing aftermarket mods. Great write-up though.

 

I should be getting my pulley by this weekend also, 5at. Do you feel any difference, like is it actually worth it? Thanks


Martin
2003.5 BS G35
Nismo Aero/Sport Package
Injen CAI
B+G Springs
ADR M-Classic 19's..

 

does it void warranty?

 

mai,
Technically no, but in all actuality it sure does!!! Dealership will blame the pulley for premature engine failure and you will be stuck proving them wrong in court. I know there is this concept of being "innocent until proven guilty" and the MM act says that "the dealer must prove the damage was caused by the mod" (loosely quoted), but the dealership can choose to take the easy way out and blame the mod and you're SOL.

301-bhp!!! ...and growing!

 

I agree with neff. Even though the MM act is supposed to protect consumers of aftermarket parts, etc., in all actuality, if the dealer wants to play hard-ball, you're screwed. Many manufacturers, dealers, vendors, etc., will spout the 'protection' afforded by the Act. 'Here's the MM Act. It'll protect you.' However, the time and $ necessary to pursue a claim under the Act will often be a barrier few are willing and/or have the resources to overcome.