Hi guys,

Is it possible to remove the crank pulley and front main seal without removing the entire front end? Is there enough clearance if you just pull the radiator and fans? I'd rather not have to disconnect the condenser and then recharge the AC system...

I've had an oil leak from behind the crank pulley for awhile. I'm hoping it's just the front main seal since it sounds like the seal between the oil pan and timing cover is a much bigger job. I was just going to start with the front main seal and if it turns out it's the upper oil pan seal then I'll put things back together and plan that job for another day.

Thanks in advance!

 

The circular seal around the crank shaft is replacable by just taking the crank pulley off and pulling the seal out and the new one will drop/push in. Obviously, make sure everyting is clean and I will put a very thin coating of RTV black on the timing chain case (where the seal pushes in). It’s pretty simple to be honest.

But yea, the oil pan ‘half-moon’ seal is difficult and requires the oil pan removal & installation.

 

Thanks. Yea, I'd like to just start with the front main seal since it seems like a much simpler job.

Do you know if there's enough space to do the the front main seal if you just pull the fans and radiator? It seems like people swap crank pulleys without removing too much stuff...

 

There should be enough space to replace the seal without pulling the Radiator or Fan Package. I recently replaced my crank pulley for a Fluidampr unit. Here's what it looks like with the pulley off. I didn't need to remove anything else from the vehicle aside from accessory belts and the lower splash shield. Definitely easier to do from underneath the car.
Cheers!
-Icer


Crank Pulley Removed, exposing front main seal.

 

Oh wow thanks for the pic!

Is there space to get an impact on there? I don't think the crank pulley has ever been removed on this car (bought used at 60k, currently at 120k) so I'm not sure how stubborn the crank pulley will be..

I have a quickjack so lots of room to access stuff from the bottom 👍

 

What Icer said…

I doubt you can get a impact in there but you can get a breaker bar. If you need an impact that means it’s seized on or someone has put it on too tight …

 

Yep! To fit an impact in there, you would need to pull the whole front end off, honestly not worth it!
Cheers!
-Icer

 

I remember having a breaker bar on it and used a long cheater bar on the handle of the breaker (used my 3 ton jack handle). As for the pulley, you have to secure it so it does not spin freely. Some people have tied it down seen in this thread:

https://my350z.com/forum/2003-2009-n...lley-bolt.html

also a good time to replace/delete the idler pulleys depending on which model you have along with belts!

 

I used my starter and a bar on the ground to break mine loose.

 

Both of those options sound better than what I did. I basically did a "squat" while laying on the ground and bracing my feet against the wheel crib. This way, I was able to use all of my body's strength without hurting myself. Even then, it was not easy! Cheater bar + jack handle to provide even more leverage and it was still one tough bolt to crack. Note that the crank bolt needs to be torqued an additional 90* after bottoming out. I used a paint pen to mark the bolt & pulley for the final torque down.

Definitely check your tensioner pulleys while you're in there, I found that my AC tensioner bearings were in the early stages of failure. I ended up coming back and replacing both tensioners with new OEM units. Also as Bak3rme stated, delete the useless idler pulley by the PS pump, if you have an earlier year (2003-2006). I think only the 2006.5 350Zs came from the factory with the pointless fan clutch idler deleted. NOTE: This simple mod does require a new ALT/PS belt since the lengths are different. You also need a spacer/washer to fill in the gap left behind from removing the old idler bracket. There's a post on these forums that gives the Nissan P/Ns for both.
Cheers!
-Icer

 

Thanks. I have an '04 so ordered the Z1 crank pulley kit that includes the spacer for the pulley delete and shorter belt. Will check out my other idler pulleys when I have everything off.

 

Can I just break the crank pulley loose with the car in gear while it's still on the ground?? I read some people tried the parking brake in the air but sometimes it will still rotate?

 

I had all 4 wheels off the ground. Supported by my homemade wheel cribs. E-brake on tight with trans in 5th or 6th gear. This worked for me. I could hear some tension in the drivetrain. But no wheel movement.

With the e-brake on, car in gear, and rear wheels in the air, yes, there is a chance the wheels will rotate depending on the brake shoe condition and adjustment. This is why I kept weight on the wheels.
Good Luck!
-Icer

 

Is there any reason it would be bad to break it loose before jacking up the car?

 

Not really. If you can fit a long breaker bar down in there from the top, that will work. You just need to be careful, if it breaks loose violently with all your weight behind it, you could end up sailing the breaker bar (and your knuckles or head) into your headlamp, fender, hood, and other important parts of the car! Never a good time if/when that happens. This is the primary of the reason why I prefer to "pull" vs. "push" when dealing with difficult fasteners.
Cheers!
-Icer

 

Thanks for all the tips. Just wanted to post an update and pics.

Managed to get it off eventually. Tried from up top with a breaker and extension but wouldn't budge. Put it up on my quickjack and decided to pull the fans to use my impact. There's actually enough space to fit a Milwaukee m12 stubby impact. Tried with the impact for a bit but my high output battery went bad recently so it didn't have enough torque with my regular batteries.. Finally tried the breaker from the bottom and was able to break it free (locked in place with parking brake).

Got off the crank pulley and pulled the front main seal. I *think* it was the front main rather than the upper oil pan seal based on the splash pattern. Oil was spread pretty evenly in all directions around the crank. Installed a Z1 crank pulley and new belts. Did the idler pulley delete while I had everything off. No leaks so far so really hoping that was it.

Thanks again for the info and tips!

 

Hey mcubed,

Hate to point it out, but you're missing the spacer washer for the pulley delete. The PS pump really should have this to prevent the pulley/belt from going out of alignment.
See pic.
-Icer

 

Haha thanks good eye!

I was gonna post another thread asking for tips on installing the spacer. I had to really work it to get the pulley bracket off. I can't even get the edge of the spacer started. Even with the ps bracket bolts loosened... I can't get a good angle to pry the bracket at all for extra clearance either. Any tips?

I think I saw a video where someone grinded the spacer down a bit to get it to fit..

Also is it ok to leave the other idler pulley bracket bolts off? They bottom out without the bracket.

 

You shouldn't need to remove the PS pump, I think what I did was loosen the bolts securing the PS pump and then rotate it or use a pry bar to give me the clearance needed to slip in the spacer. I did this so long ago, I don't remember the exact process. I think there's a press fit roll pin or sleeve on the PS pump which is why it's so difficult to get movement out of it. I would not grind it to make it fit. The spacer is already machined to be an exact fit, grinding it down could cause belt alignment issues.

If you haven't figured it out by the weekend, I'll take a look at my spare engine block (sitting on my stand) and see what the best method for tackling this is.
Cheers!
-Icer

 

Regarding the idler pulley bracket bolts. I re-installed mine just to fill in the holes and keep things clean. I think the ones at center of the block pass through the timing cover and thread into the block, so I look at this as additional timing cover clamping force. It's probably unnecessary, but I like to keep bolt holes clear of debris.
Cheers!
-Icer