Change your differential gear oil!

[Q451990]

I got around to doing my first differential oil chage on the G today at 29K - and now I wish I had done it sooner. I found a good bit of metal filings on the drain magnet and suspended in the oil. From everything I have read, it's typical with the first drain on a new differential.

If I had it to do over again, I think I would change it at 5K and then at the next oil change or two. I used Valvoline 80W-90 conventional oil this time. May use conventional one more time at the next oil change - then change it over to Synthetic oil on the following change.

The only full synthetic I can find in the specified 80W-90 is Amsoil, so I'll be looking for a reasonably price supplier locally. I'm not sure why Infiniti was so specific for this weight vs. what I find in the FSM for my Q and Truck, which shows a variety of gear oils based on different ambient temperatures.

Also, if anyone reads this later, the drain and fill bolts use a 10MM Hex (Allen head) driver. And it uses about 1.5 quarts of oil.

Heath

[IlsG35]

nice to know i was lookin in to doin my fluid change today only reason y i didnt do it was becuase i didnt know which weight to use..now i know n ima do it tomorrow thanks for the info...

[Q451990]

I'm glad I could help!

I would check your service manual and/or owner's manual... I think it's the same in the '03, but I don't know for sure. Might want to check and change the oil in your M/T as well. If you don't have a copy of your owner's manual, you can get it at http://www.infiniti-techinfo.com as a .pdf, and you can get the FSM (factory service manual) at http://www.nicoclub.com/FSM/G35/

Good luck, and please post up what kind of condition the oil is in that you drain out!

Heath

[gwoods]

Does your g have a limited slip and if so did you put in a friction modifier for the clutchs?

+1 on frequent diff and transmission fluid changes

[Q451990]

No LSD (i'm 90% sure) on the sedan in 2005... someone correct me if I'm wrong?

Heath

[tollboothwilley]

2003 didn't. 2004+ did.

To add be more clear:

2003 sedans didn't have an option for VLSD

2004-2006 sedans had a sport package option which came with VLSD

2007 sport sedans have VLSD, base & journey have ABLS

2003-2004 coupes had VSLD if it was a Performance Wheel and Tire package option, which meant 18" wheels auto or manual.

2005-2007 coupes only those with the Sport Suspension Package had VSLD

*The 18" wheel option for 05/06 is only that, wheels and tiresVLSD became part of the Sport Tuned Suspension package for 05/06*

To clearify what "sport package" on the sedans:

Breakdown of oem VLSD fitment G35 sedans, all production

03 AT with or without sport suspension: NO03 MT: NO (has sport suspension standard of course)

04 AT: with or without sport suspension: NO04 MT: Yes

05/06 AT with sport suspension: Yes05/06 AT without sport suspension: No05/06 MT: Yes

[tel7726]

I'm a believer! Anyone know the proper torque for the filler and drain plugs? I assume I can get the drain plug gasket from the stealer.

[Q451990]

Drain plug "crush washers" don't really appear to be crush washers like the ones on the oil pan. More like just washers. My local dealership didn't have them in stock... said they haven't had any since 2006 and never use them during their diff. service. So I bought the two Infiniti of Scottsdale had in stock while getting something else today. I'll just keep an eye on it for now, and then put the new washers on when I put the synthetic oil in in about 8000 miles.

Torque spec. is 25 ft/lb.

Heath

[MoonRiver]

I got around to doing my first differential oil chage on the G today at 29K - and now I wish I had done it sooner. I found a good bit of metal filings on the drain magnet and suspended in the oil. From everything I have read, it's typical with the first drain on a new differential.

If I had it to do over again, I think I would change it at 5K and then at the next oil change or two. I used Valvoline 80W-90 conventional oil this time. May use conventional one more time at the next oil change - then change it over to Synthetic oil on the following change.

The only full synthetic I can find in the specified 80W-90 is Amsoil, so I'll be looking for a reasonably price supplier locally. I'm not sure why Infiniti was so specific for this weight vs. what I find in the FSM for my Q and Truck, which shows a variety of gear oils based on different ambient temperatures.

Also, if anyone reads this later, the drain and fill bolts use a 10MM Hex (Allen head) driver. And it uses about 1.5 quarts of oil.

Heath

I just did my 07 with 2970 miles. Yes the plug is covered with a layer of black mixture of oil and metal filling. The oil drained out was kind of black.

I also replaced the transmission oil. There were some white metal filings (lager than those on the differential) on the drain plug. Getting to the transmission filler plug requires crawl under the car, but since I got the matal filling cleaned out, it's worth the effor.

[MoonRiver]

Found an excellent you tube video of the job. Here it is

http://www.youtube.com/watch?v=mDdYuWkWjjg

[adren77]

Found an excellent you tube video of the job. Here it is

http://www.youtube.com/watch?v=mDdYuWkWjjg

Great video.

Anyone know if the differential and trans fluid in a 6MT are the same thing, or you have to change them independently?

[MoonRiver]

In 07 they are different grades. transmission uses 75w-85 or 90 if ambient temperature never below 32F, differential 80w-90. Don't know about other model year but most likely they are the same. I mistakenly put 80w-90 into both, then I realized my mistake before I drive it. How stupid can you get? I wasn't sure it's ok so I called the dealership the next morning and was told that It's better to follow what manual says or it'll void the warrenty. So I had to redo the whole thing, change to 75w.
Modified by MoonRiver at 8:45 PM 2/9/2008