Rear Differential Gear Oil Comparison?

[Deleted member 89374]

Amsoil Severe Gear is arguably the best gear oil on the market.

I think it's up there with some of the best for street use, but I would hardly call it the best. It's a modern and proprietary formulation for sure. If I was going to the track, or doing something more out of the ordinary with my vehicle, I doubt I would use Severe Gear for that purpose.

 

[CleanSump]

I think it's up there with some of the best for street use, but I would hardly call it the best. It's a modern and proprietary formulation for sure. If I was going to the track, or doing something more out of the ordinary with my vehicle, I doubt I would use Severe Gear for that purpose.

What would you rate as best? Always interested in better, or someone's idea of better to think about.

 

[tblt44]

I use Mobil 1 75w 90 or valvoline and change it every 50k. Either is still pretty clean when I change mine.

 

[CarbonSteel]

I think it's up there with some of the best for street use, but I would hardly call it the best. It's a modern and proprietary formulation for sure. If I was going to the track, or doing something more out of the ordinary with my vehicle, I doubt I would use Severe Gear for that purpose.

What would you use? In two of my trucks, I towed pretty heavy for nearly 50% of the miles I put on them and Amsoil SG held up well viscosity and TAN wise.

 

[Deleted member 89374]

What would you rate as best? Always interested in better, or someone's idea of better to think about.

What would you use? In two of my trucks, I towed pretty heavy for nearly 50% of the miles I put on them and Amsoil SG held up well viscosity and TAN wise.

When I had my 2016 RAM 1500, I used AMSOIL Severe Gear 75W-140 rear/75W-90 front diff. In the Durango, I put Red Line 75W-90 front and rear (this is some smelly stuff, lol). For my wife's Jeep GC WK2 I ordered 75W-90 Differential Life from HPL. You might want to ask @High Performance Lubricants about their gear lubes. Their street gear oil is also used in racing applications. I believe that top-tier gear oils will perform well.

 

[cb_13]

When you have 225,000 miles on your original diff, using a single product of your choice, come and tell us about it.

I had 180k on the original differentials on my 04 F150. Nothing but Motorcraft. Changed rear fluid at 90k when I replaced the axle seals due to one leaking. Changed the front to 75w90 from 80w90 at 150(ish)k.

I don’t believe the Motorcraft to be any magical product just an example of meeting spec on a modern well built differential being good enough. Also it was readily available to me working at a dealership and I had enough partial quarts leftover from other jobs that it saved me from buying much if any fluid.

 

[CarbonSteel]

When I had my 2016 RAM 1500, I used AMSOIL Severe Gear 75W-140 rear/75W-90 front diff. In the Durango, I put Red Line 75W-90 front and rear (this is some smelly stuff, lol). For my wife's Jeep GC WK2 I ordered 75W-90 Differential Life from HPL. You might want to ask @High Performance Lubricants about their gear lubes. Their street gear oil is also used in racing applications. I believe that top-tier gear oils will perform well.

I have a bit of Amsoil left, but truth be told, the Valvoline I have been using works well. I change my gear oil often enough in the Jeep it does not make sense to go too far away from off the shelf stuff.

 

[Gebo]

OH, but the bag. I love that squeeze bag.

 

[Deleted member 89374]

I have a bit of Amsoil left, but truth be told, the Valvoline I have been using works well. I change my gear oil often enough in the Jeep it does not make sense to go too far away from off the shelf stuff.

How does it look and smell when you drain it? How often do you change it?

 

[CarbonSteel]

How does it look and smell when you drain it? How often do you change it?

Visually, it is dark, but no odd smell. The Dana Advantek axles in the Jeep generate more metal than any other I have owned or have had experience. Thus the reason why I change it every 20K and use off the shelf lubes.

 

[Deleted member 89374]

Visually, it is dark, but no odd smell. The Dana Advantek axles in the Jeep generate more metal than any other I have owned or have had experience. Thus the reason why I change it every 20K and use off the shelf lubes.

I wonder if you tried something like Red Line if it would make a difference. Sometimes you can find it priced very reasonably.

 

[CarbonSteel]

I wonder if you tried something like Red Line if it would make a difference. Sometimes you can find it priced very reasonably.

Not sure, note that I am imposing my OCI based upon wear metals which neither Amsoil or other synthetics has curtailed so it is just easier to change it.

 

[roaniecowpony]

I'm in the process of changing out all the fluids in my 2014 GMC 1500 and stumbled upon this thread. I believe CarbonSteel is one of my fellow JLWrangler forum members.

So yesterday, in my quest for fluids, I went to one Walmart (for M1 EP), and 3 different chain autoparts stores. I was looking for a Dexron VI and differential gear oil as well. What struck me was the very narrow selection of GL5 gear oil in all of these stores.

I read this thread and didn't see Royal Purple mentioned. I only bring it up because it is one of the brands that is available in my local chain (O'Reilly) auto parts stores in southern Cal. So I'm curious if RP MaxGear is a high performing differential gear oil. Any information would be helpful.

Also, if RP is not a great choice, what other local sources of better gear oils are out there? I'd prefer not to resort to mail order gear oil.

 

[IveBeenRued]

This is for my 2012 Subaru Impreza.
2500 miles Changed out factory. Fluid was murky brown and I could not see through it as it drained. Put in Royal Purple 75W-90.

25K miles. Royal Purple came out black with a hint of sparkles. Installed AMSOIL Severe Gear 75W-90.

50K miles. Drained the AMSOIL and it came out a translucent amber, just a hint darker than the original fluid condition. More AMSOIL went in.

125K miles (75K on fluid) and the AMSOIL SG came out looking like this:

Needless to say, I use AMSOIL in all of my diffs now.

 

[Deleted member 89374]

I'm in the process of changing out all the fluids in my 2014 GMC 1500 and stumbled upon this thread. I believe CarbonSteel is one of my fellow JLWrangler forum members.

So yesterday, in my quest for fluids, I went to one Walmart (for M1 EP), and 3 different chain autoparts stores. I was looking for a Dexron VI and differential gear oil as well. What struck me was the very narrow selection of GL5 gear oil in all of these stores.

I read this thread and didn't see Royal Purple mentioned. I only bring it up because it is one of the brands that is available in my local chain (O'Reilly) auto parts stores in southern Cal. So I'm curious if RP MaxGear is a high performing differential gear oil. Any information would be helpful.

Also, if RP is not a great choice, what other local sources of better gear oils are out there? I'd prefer not to resort to mail order gear oil.

AMSOIL Severe Gear is good stuff and extremely easy to order.

Local choises are Valvoline, Mobil 1, and Delvac 1 gear oils, all good choices.

Royal Purple is the worse. If you search around the off-road forums, you'll find many people who had nothing but problems and premature wear with Royal Purple. It's a ruthless company who dies their fluids as a gimmick, cashing in on its former glory.

 

[roaniecowpony]

AMSOIL Severe Gear is good stuff and extremely easy to order.

Local choises are Valvoline, Mobil 1, and Delvac 1 gear oils, all good choices.

Royal Purple is the worse. If you search around the off-road forums, you'll find many people who had nothing but problems and premature wear with Royal Purple. It's a ruthless company who dies their fluids as a gimmick, cashing in on its former glory.

Thanks RK.
I read this test report by Amsoil. Not sure it's not biased, but it's a data point. http://www.syntheticwarehouse.com/brochures/g2457_gearlube_study.pdf

Looks like the GM brand also did well.

 

[Elkins45]

Quite OK. Amsoil Severe Gear is arguably the best gear oil on the market.

Every gear oil is arguably the best gear oil on the market. For some the argument is just stronger than others.

 

[Deleted member 89374]

Thanks RK.
I read this test report by Amsoil. Not sure it's not biased, but it's a data point. http://www.syntheticwarehouse.com/brochures/g2457_gearlube_study.pdf

Looks like the GM brand also did well.

You're very welcome

The only problem with OEM gear oil, such as the GM you referenced, is that every now and then they change suppliers.

AMSOIL Severe Gear is a propriatery formulation that's based on their wind turbine oil.

I'm currently trying Red Line gear oil and bought 6 quarts of HPL for my wife's Jeep.

Any majod well respected brand will do a good job for you.

Is Royal Purple a well respected brand? I think they lost a lot of that respect over the past decade by cutting corners and switching to cheaper ingredients in their oils.

 

[dnewton3]

Don't focus on what the label says. Rather, concentrate on what the lube can do; look at its performance and not its pedigree.
Look at this site and then open the QPL (qualified product list) link

Performance Review Institute (PRI) - We Protect What Matters

p-r-i.org

These lubes are tested for what they ACTUALLY DO in real, high-stress use.
There are syns on this list you'd recognize (and actually a few that are curiously missing).
There are conventional lubes on this list, and pass the same rigorous testing as the syns.

Pick one of these and don't worry about your differential.



NOTE: if you need a gear oil for a manual trans with yellow metal compatibility, you'll want to get a product specific for that application such as a GL-4, etc.

 

[gman2304]

Looks like the GM brand also did well.

I agree. I changed the FF in my 2005 G80 open diff at 200,000 miles. The GM oil obviously did it’s job. Went back with Delvac1 and now at 230,000 miles still quiet as a mouse.