DIY: Replace Serpentine Belt 07+ G35 (and probably G37)
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Joined: Feb 2018
Posts: 494
Likes: 49
Just did this on my '08 G35X this evening. Will confirm what a few have already said and that is, remove the bottom engine shield and work from the top and bottom when it comes to routing the belt. Certainly makes things easier.
Another thing is, and not sure why this varies, but my tensioner used a 3/8" drive hole, not 1/2" drive. Use the thinnest ratchet you have too or even better, a serpentine belt tool (the ones made from flat bar with a 3/8" square welded on the end). A pipe on the ratchet for extra leverage is real helpful too - that tensioner was much stiffer than I expected. Without the cheater, I don't think I could have moved it with one hand/arm and had a free hand to insert the allen wrench.
Another thing is, and not sure why this varies, but my tensioner used a 3/8" drive hole, not 1/2" drive. Use the thinnest ratchet you have too or even better, a serpentine belt tool (the ones made from flat bar with a 3/8" square welded on the end). A pipe on the ratchet for extra leverage is real helpful too - that tensioner was much stiffer than I expected. Without the cheater, I don't think I could have moved it with one hand/arm and had a free hand to insert the allen wrench.
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Joined: Nov 2010
Posts: 26
Likes: 0
From: Va beach
just wanna say thank for the guide! Everything went well and my squeaky belt noise went away like that just by following your guide. I got to the part where I needed a half inch pry bar to pry the tensioner loose but ended using a normal ratchet with a 19 inch wrench to create some leverage for my girlfriend to put the Allen wrench in the hole from the top of the engine once they lined up! If you don’t have one it’s an alternative! My 2008 g35x is running quiet & smooth! The shop wanted $300 and it took me 2 hours and $20 belt from bandó 6pk2060. Your guide really came in handy when it came to figuring out how to put it back on in the right pattern.
so i had thought my belt was burning/smoldering a little and i knew it was squeaking so i decided to replace it (it's also about 30k miles overdue according to the owner's manual). i went to nissan and they wanted $60 for the belt but autozone had it for $34 (it had to be ordered but arrived in 2 days). it's a dayco #5070810.
all in all it took me 30 minutes working outside in 4 degree weather, but you could do it in 15 if you wanted, i struggled with getting the belt on the last pulley until i realized the easy way.
full disclaimer, the first 3 photos are from turtleboy on my350z.com. the photos are fairly identical except for the coolant overflow tank but thats minor so i just lifted his pictures.
and also, since i have to say it, do this at your own risk. i am in no way responsible for any injuries or damage you do. sorry, but just covering my butt.
you'll need:
new belt
7mm hex key or similar size
10mm deep socket (or plain 10mm with extension)
1/2 breaker bar for belt replacement (i purchased a 3/8" breaker bar set at autozone some years ago for maybe $20 which had a 1/2" adapter for it and several sockets, well worth it)
here we go....
1. get yourself a 10mm socket and remove the bolts for the coolant overflow tank, and detach the two hoses. the only difference for ours is that the bolt heads are facing up, not towards the windshield. remove the tank and put it somewhere out of the way.
Attachment 241284
2. slip your half inch breaker bar into the tensioner slot and turn *counter-clockwise to release the tension
Attachment 241285
3. stick the hex key in the hole by the top arrow to hold the tensioner. remove the breaker bar now, it will only be in the way.
Attachment 241286
4. this is the drive belt arrangement for the 08 g35x. it's in the owner's manual, double check if you think yours is different.
Attachment 241287
5. pull the old belt off and put the new one on in the configuration shown in the owner manual clip. below is just are two photos of my engine bay for reference. they're not that great but better than nothing.
Attachment 241288
Attachment 241289
note the pulley in the red circle, do this *last. it made life sooooo much easier. align the belt onto the remaining pulleys then pull it up and onto the final pulley. it will go quite smooth.
Attachment 241290
6. next just put the breaker bar back in and once you're sure the belts are properly lined up turn it a little more counter-clockwise to release the hex key then slowly turn it *clockwise to let it re-tension the belts.
7. replace the overflow tank
8. start it up and take a peek to make sure everything is fine.
oddly enough my belt barely looked worn but i suppose it required replacement anyway since i've seen some people eat belts alot earlier than expected on here.
i hope this helps! cheers!
Bob
all in all it took me 30 minutes working outside in 4 degree weather, but you could do it in 15 if you wanted, i struggled with getting the belt on the last pulley until i realized the easy way.
full disclaimer, the first 3 photos are from turtleboy on my350z.com. the photos are fairly identical except for the coolant overflow tank but thats minor so i just lifted his pictures.
and also, since i have to say it, do this at your own risk. i am in no way responsible for any injuries or damage you do. sorry, but just covering my butt.
you'll need:
new belt
7mm hex key or similar size
10mm deep socket (or plain 10mm with extension)
1/2 breaker bar for belt replacement (i purchased a 3/8" breaker bar set at autozone some years ago for maybe $20 which had a 1/2" adapter for it and several sockets, well worth it)
here we go....
1. get yourself a 10mm socket and remove the bolts for the coolant overflow tank, and detach the two hoses. the only difference for ours is that the bolt heads are facing up, not towards the windshield. remove the tank and put it somewhere out of the way.
Attachment 241284
2. slip your half inch breaker bar into the tensioner slot and turn *counter-clockwise to release the tension
Attachment 241285
3. stick the hex key in the hole by the top arrow to hold the tensioner. remove the breaker bar now, it will only be in the way.
Attachment 241286
4. this is the drive belt arrangement for the 08 g35x. it's in the owner's manual, double check if you think yours is different.
Attachment 241287
5. pull the old belt off and put the new one on in the configuration shown in the owner manual clip. below is just are two photos of my engine bay for reference. they're not that great but better than nothing.
Attachment 241288
Attachment 241289
note the pulley in the red circle, do this *last. it made life sooooo much easier. align the belt onto the remaining pulleys then pull it up and onto the final pulley. it will go quite smooth.
Attachment 241290
6. next just put the breaker bar back in and once you're sure the belts are properly lined up turn it a little more counter-clockwise to release the hex key then slowly turn it *clockwise to let it re-tension the belts.
7. replace the overflow tank
8. start it up and take a peek to make sure everything is fine.
oddly enough my belt barely looked worn but i suppose it required replacement anyway since i've seen some people eat belts alot earlier than expected on here.
i hope this helps! cheers!
Bob
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Joined: Feb 2024
Posts: 1
Likes: 0
G35X Stock
Just did this, I rented the serpentine belt tool from Advanced, I did not have any issues with fan clearance.
Removed the res tank and did it from above, took about 30 min.
One tip save the middle upper pully for last, tuck the belt under that pully, gives you more slack to get the belt around the lower pullies.
Removed the res tank and did it from above, took about 30 min.
One tip save the middle upper pully for last, tuck the belt under that pully, gives you more slack to get the belt around the lower pullies.
Registered User
Joined: Feb 2023
Posts: 7
Likes: 3
From: CT
G35x
The shredding of these belts seems to suggest a misalignment, First belt I changed was starting to shred and looking closer it was a tooth off at the alternator so I assumed that caused the shred. Looking closer though the tensioner pulley and alternator are not well aligned. I recently purchased another tensioner and alignment is improved but that tensioner pulley is so close it appears it can rub the alternator. Anybody see that on there car? 08 G35X
Last edited by mjtct; Oct 30, 2025 at 01:02 PM. Reason: Add detail
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