Thanks, I know from some of my past fluid analysis testing (on other cars) that differential wear is directly related to viscosity, I don't want to go too high but a good synthetic in the general range of 75w90 should be safe, 75w85 is still an option I can explore as you said, going with synthetic alone is a plus. Thanks for the replyGood idea on switching over to a quality synthetic. I currently have Amsoil in my Grand Cherokee differentials. Redline in the Wrangler & Z.
Differentials take a long time to warm up which is one of the advantages of a thinner OEM-spec fluid, and why I prefer to run OEM-spec on street cars. Both my Jeeps stood up to the TX summer heat when we lived in Dallas & Houston running 75W-85. The Wrangler sees off-road duty and both tow.
Both Redline & Amsoil offer a 75W-85 GL-5 gear oil. Switching to a synthetic alone is already a huge upgrade vs. the conventional stock crap irregardless of weight.
If you're changing the fluid in a Sport model (open diff), it already has synthetic in it from the factory. Factory weight is 75W-80. The Performance/Nismo with the LSD uses a conventional 75W-90. You also need a Hypoid gear oil. The oil will shear and cause excess wear if you do not. I'm using Klotz GL5 synthetic in my Sport, as it's about the only oil aside form the factory Nissan in 75W80 weight. that meets all the above criteria.I'd like to dump the differential fluid at the 2000 km mark, same as the engine oil - break-in point. I tend to prefer Amsoil gear oil , I will only drive my car in warm weather months, as it is stored for winter. Canadian summers can be quite hot. 75w90 is my preference over the thinner factory fluid (Sport Auto model with no LSD), Amsoil is synthetic but the non-lsd model doesn't seem to mind a synthetic fluid.
Thanks for the great info. Do I need to look for the words Hypoid Gear Oil on the product or is GL-5 all that is needed ? I tend to use Amsoil Severe Gear in all of my diffs on other cars, I will check this out to be sure it is compatible, thank you.If you're changing the fluid in a Sport model (open diff), it already has synthetic in it from the factory. Factory weight is 75W-80. The Performance/Nismo with the LSD uses a conventional 75W-90. You also need a Hypoid gear oil. The oil will shear and cause excess wear if you do not. I'm using Klotz GL5 synthetic in my Sport, as it's about the only oil aside form the factory Nissan in 75W80 weight. that meets all the above criteria.
Changing the fluid at 2k is a good call. I drained mine at 6900 miles and there was a lot of shavings and sludge on the metallic drain plug.
Most rear differentials have hypoid gears, but even so, the fluid will usually specify this on the label. Nissan specifies in the owners manual to use GL5 synthetic hypoid in the Sport.Thanks for the great info. Do I need to look for the words Hypoid Gear Oil on the product or is GL-5 all that is needed ? I tend to use Amsoil Severe Gear in all of my diffs on other cars, I will check this out to be sure it is compatible, thank you.
Thank you. I think Amsoil is compatible with Severe Gear fluid, I was going to use 75w90. My Subaru BRZ had an odd viscosity like the Z Sport and I ran 75w90 in it.Most rear differentials have hypoid gears, but even so, the fluid will usually specify this on the label. Nissan specifies in the owners manual to use GL5 synthetic hypoid in the Sport.
What makes the fluid hard to find on the Sport model is the 75W-80 weight. It's not common. The 75W-90 weight used in the Performance/Nismo is common.
You're welcome I made a vid on changing the diff fluid in the Sport a few weeks ago. I attached it below for you when the time comes.Thank you. I think Amsoil is compatible with Severe Gear fluid, I was going to use 75w90. My Subaru BRZ had an odd viscosity like the Z Sport and I ran 75w90 in it.
I've got some time to think about this, I need to get to the 2000 km mark before the car goes into winter storage , early October, so I have my work cut out for me, then I have some time to think about the viscosity. Thanks for the info
That is great, thank you. I did diff fluid changes on my Honda S2000 a few times, and my Subaru BRZ a couple of times. Thanks for posting this as I can have a look to see how similar the process may be, I have yet to go under the rear end, but I have seen under the front end.You're welcome I made a vid on changing the diff fluid in the Sport a few weeks ago. I attached it below for you when the time comes.![]()