Differential Whine (Revised Factory Diff with Cooling Fins?)

BGTV8 · 03-18-2015, 12:44 AM

I don't recognise this diff housing .... my Z34 (Japan built) has a "smooth" case - I have the finned NISMO diff-cover and I did notice an increase in NVH when I fitted it, and that got worse when I fitted Whiteline bushes - just something else to tolerate (or I just turn the muzak up a bit).

This diff housing looks a bit like the big-bertha (R230) diff in my 300ZX TT which is an amalgam of 5 different cars that my nephew is slowing building into a race-car. Best get the car on a hoist and try and find some identifying marks on the diff case itself to identify exactly what it is.

I'm not sure I like that drain plug hanging down underneath albeit that the exhaust would take a pounding before it was hit, but you never know.

lewie145 · 03-19-2015, 10:46 AM

Thanks for the reply's guys, I just got word back from Nissan of course they did not hear anything and they were trying to charge me a diagnostic fee which i immediately refused. They said it could be my tires which are not a warranty item... They also said they checked all the bearings, but did not explain if they checked the differential bearings so my wife is going to ask if they actually checked the differential not just the wheel bearings. Ya pretty sure tires don't make a high pitched piercing whine only at highway speeds.

Honestly I can deal with the whine as long as I know the differential is operating correctly.

I am going to change the fluid and see if that helps.

Is there an easy way to identify whiteline bushings while the car is lifted?

My buddy works at a shop with a lift so we can use that when replacing the diff fluid.

03-18-2015, 12:44 AM	#1 (permalink)
BGTV8 A True Z Fanatic Join Date: Dec 2009 Location: 03350 Australia Posts: 1,516 Drives: 09 Nissan 370Z M6 Rep Power: 39975	I don't recognise this diff housing .... my Z34 (Japan built) has a "smooth" case - I have the finned NISMO diff-cover and I did notice an increase in NVH when I fitted it, and that got worse when I fitted Whiteline bushes - just something else to tolerate (or I just turn the muzak up a bit). This diff housing looks a bit like the big-bertha (R230) diff in my 300ZX TT which is an amalgam of 5 different cars that my nephew is slowing building into a race-car. Best get the car on a hoist and try and find some identifying marks on the diff case itself to identify exactly what it is. I'm not sure I like that drain plug hanging down underneath albeit that the exhaust would take a pounding before it was hit, but you never know. KapitalZ likes this.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Z1 Motorsports: Full Differential Upgrade Kit/Whiteline Diff Bushings	John@Z1	Drivetrain/Engine	39	06-12-2017 09:46 AM
differential whine	angelmanuel	Nissan 370Z General Discussions	5	02-21-2015 05:15 PM
stick on cooling fins	rlhotka	Engine & Drivetrain	10	06-18-2014 08:11 PM
differential whine	Pharmacist	Nissan 370Z General Discussions	9	03-21-2011 07:42 AM
Z34/370Z air-cooling fin equipped diff. rear cover	AK370Z	Engine & Drivetrain	2	04-13-2009 10:35 AM

03-19-2015, 10:46 AM	#2 (permalink)
lewie145 Base Member Join Date: Nov 2014 Location: Northwest Indiana Posts: 6 Drives: 11 Nissan 370z BC M6 Rep Power: 12	Thanks for the reply's guys, I just got word back from Nissan of course they did not hear anything and they were trying to charge me a diagnostic fee which i immediately refused. They said it could be my tires which are not a warranty item... They also said they checked all the bearings, but did not explain if they checked the differential bearings so my wife is going to ask if they actually checked the differential not just the wheel bearings. Ya pretty sure tires don't make a high pitched piercing whine only at highway speeds. Honestly I can deal with the whine as long as I know the differential is operating correctly. I am going to change the fluid and see if that helps. Is there an easy way to identify whiteline bushings while the car is lifted? My buddy works at a shop with a lift so we can use that when replacing the diff fluid.