Finally got a weekend free so spent some time today getting the old diff off.

Couple questions:

1) With the exhaust/mufflers and pumpkin out I have tons of room underneath. One thing I noticed is the driveshaft slides back and forth A LOT (front to back, not spinning it) - Like 7-8". It feels so loose like I can pull it off the transmission. U-joint in the front is tight. Is that normal?

2) The replacement diff has a bent breather tube. The old one has a 90 degree bend in it whereas the new one is almost bent like a U. There's no cracks or breaks in it so assume it's fine to use as the air can still travel through it for the pressure equalization once the oil gets hot. Someone please confirm thats ok ...

Thanks all.

 

That's normal, the driveshaft just slides into the rear of the transmission.
If there are no cracks or pinched-off portions of tubing, you should be okay

 

Gracias!

 

Think I have a problem ... should there be a rubber bushing between the washer and the bottom of the diff mount? From memory I think there is, but don't have the original mounting hardware anymore to tell if I'm missing one or not. Can someone post a pic of their pumpkin OEM mounts?

Thanks!!

 

Crapola... I'm missing the upper and lower stoppers according to the service manual. F-ing F. ****. And Nissan parts is closed today. ****.

 

I'm interested in the outcome.

I have a similar Whirring noise only while decelerating. In my case i think i hurt something when at the track. I took her down the drag strip for 3 runs and on the last one had bad wheel hop in 3rd gear. When i left the track i started to here this noise on deceleration but at first though I was hearing things as I usually have the music up.

I dont have the 4.083 gears but did put in a carbonetics LSD. I changed the fluid but the sound did not go away. I have not yet taken the car in to take the rear apart and have a look. The reason I havent had it looked at yet is I didnt want to spend any more cash right now on it and was hoping to wait until next spring as the car will be put away soon for the winter.

Will driving with this noise/issue risk damaging anything else? I was thinking of taking the Z for a 700 mile drive to quebec but this issue is holding me back risking the long drive.

 

I put 4000 miles on mine without any issues except the noise. It gradually got worse, which to me indicates something was wearing badly, but haven't opened it up yet to look for damage to anything.

I'm still waiting on the 4 little bushings so the car's sitting up on jack stands in the garage. BTW, those 4 little bushings cost $50 EACH so if you ever switch to solid diff mounts KEEP THEM, you'll save about $200 if you ever go back to stock.

 

Holy dooshbags Batman - so the dealer here told me the price was upwards of $200 for the 4... I ordered from Courtesy this morning for $24. Yeah, 2-4-dollars.

+1 to Courtesy. Part numbers are 55475 and 55474 qty 2 each. Win!

 

Ok, the problem is something in the pumpkin. Just got done swapping out the 4.083 pumpkin for a used pumpkin from an 06 (stock gears). After a stripped bolt and lots of 4 letter words later I took it out for a 30 minute drive and all the noise is gone, all the vibrations in the clutch pedal at high revs are gone, I can hear the stereo again... its so nice.

I haven't opened the 4.083 pumpkin yet (maybe this weekend) to look in there. Will post pics once I get it opened...

 

Update?

 

No update because I'm lazy. Car's been driving well and I just haven't taken the time to pull the old pumpkin apart...

 

Frizzle,

So you went back to stock pumpkin AND stock bushings? If so, it's hard to say if the 4.083 pumpkin was the culprit or the hard bushings?

 

I really hope this thread is not completely dead, I installed SPL solid diff bushings back in the Fall and other than a constant sound that i can say was probably the diff having 100% metal contact with the sub frame was fine. I had my clutch and flywheel replaced and the EXACT sound while Decelerating is happening, I would prefer not to replace my entire diff, but I wish for the Z community we could find out the exact problem

This is what I have put together about this
-Happened to Frizzle when he installed new gears, STOCK bushings, although it was blown
-Happened to me not after installing the bushings, but after replacing my Flywheel/clutch

What I am wondering is if for some reason we have not torqued down the Driveshaft right, because it isn't a bushing issue, and although it fixed it, I am not sure it is a diff issue even though I think it takes some damage from whatever is going wrong

 

Bump I'm having the same issues with my z 2004. I just started to notice the noise during deceleration. I set up an appt. wednesday to have it checked. I have jwt clutch and flywheel, nismo gt lsd, stock gears, I use motul gear oil. My mechanic says it might be ring and pinion weat car has about 95K miles. Oh i also have spl solid bushings. I never had this before and out of no where i started noticing the humming noise getting a bit louder. I hope its something simple.

 

I have them and the hum is normal. I enjoy it as long as I'm not on a long drive. But yes most likely hey are installed cooler but should help the longevity of the gear install.

 

Bad wheel bearing(s)