Differential Oil Question

When we travel with our 4Runner, we are usually towing our 5x8 off-road camper. I now have 22k miles and I should probably to an oil change in the front and rear diffs. As most of you probably know, a liter of Toyota diff oil is expensive, currently around 65$ a liter. A quart of Mobile 1 Gear synthetic gear oil is $17.50 a quart.

They are both 75w oils. The Toyota container does not list the second number, but the Mobile 1 is 75w-90.

I there any reason I could not replace the Toyota diff oil with the Mobile 1 diff oil?

 

Stick with synthetic and I think you are good.

 

Thanks for that recommendation.

 

I changed my rear and front differential fluids at 30K miles. The rear was quite dirty looking and there was powdered gunk on the magnetic drain plug. Diff fluid smells awful so don’t worry about that. The front fluid looked very clean, which is to be expected since it’s used very little.

I replaced the fluids with Amsoil Severe Gear 75W90, which is a highly rated oil. I changed them again at 50K with the same results. I also changed the transfer case oil with the Toyota 75 weight Transfer Oil (aka Liquid Gold).

I changed the rear diff again at 75K and was surprised that there still seemed to be a lot of metallic powder and debris. So at my next rear diff service I will be changing to another oil. Probably Red Line 75W90 GL-5 Synthetic.

For the transfer case at 82K I drained it and changed to Red Line MT-LV 70W/75W GL-4. The transfer case hold 1 liter (1.06 quarts), so I bought 2 quarts of MT-LV for much less than 1 liter of the Toyota version.

BTW, the plastic squeeze bags like Valvoline and Amsoil make it real easy to do the rear diff fill. For the front and transfer case you need a pump.

 

Thanks for the advice Electro Boy - I really appreciate it.

 

Any off the shelf gear oil of the correct viscosity will work.

 

I use mobil 1 and valvoline.
I prefer that valvoline but will but mobil 1 if it's cheaper

 

The Toyota can lists the oil weight. The t-case is a straight 75w.

 

+1, last summer I used the squeeze bags for the first time. Made the job SO much easier.

 

I got away with using a bag on the front diff. If you put the dispenser end on and hold it with your hand (so it doesnt fall out), it’s easy to just push the bag up there and squish it in slowly. Really love those bags.

Probably could have used a bag for the transfer case, but the Royal Purple stuff I used came in bottles.

 

BINGO!

 

A fluid transfer pump makes this SO easy. I got one from my local discount store for 6.99

I poured the qt oil bottles into a empty (and dry) 1 gallon Poland Spring bottle and dispensed from that. I used Valvoline syn for front, rear, tcase.

 

Drivers who tow trailers and boats use 75W140 or 80W140 to give better protection to diffs and run it all year.

 

So I did my front and rear diff fluid at 30,000 miles with amsoil severe gear. I'm approaching my 60,000 mile maintenance and I'm curious when using the amsoil or the recommendation still to change it every 30?

 

The recommendation per the manual is check it every 5, and change it every 15 if doing one of the special cases, so not sure where you're finding 30.

If you've only changed it once so far, then I'd probably change it again at 60. I haven't owned my 4R long enough to tell, but on my Tacoma it took two changes to get all the metal shavings out, then after that I was able to stretch the intervals out (I changed it once after 30k and it looked brand new, so I went further after that).

My advice is to take a short drive around your neighborhood to mix everything up, so all the debris comes out when you drain it. At 30k between changes on the 4R (my last service), the oil at the fill hole looked fine, but there was a lot of metal settled in the bottom.

 

What do you mean you don't know where I'm finding 30

 

I last changed mine around 100k, I'm approaching 170k and will change them in the spring. Oops.

 

Be prepared, nasally. The smell is horrendous.

 

It always reminded me of cooked onions, which I hate.

 

Can you use the 75w-90 in the t-case as well?

 

Most people do but there are a few companies like Redline that make specific 75W oil for the transfer case similar to what Toyota offers

 

You mentioned a recommendation to change every 30k; I haven't seen that, so I'm not sure where you got it from. (Like where did you see it)

 

I changed all 3 at 40,000 miles. Rear diff was nasty. T-case and front diff oil looked near fresh. I used valvoline 75w-90 in all 3. zero issues. Will do the same every 30k.

 

Someone on here put together pretty comprehensive list for maintenance schedules I'll have to see if I can find it I thought I saved it somewhere. That was the first place I saw that then I think car Care nut was the second

 

If you aren't towing, the only basis in Toyota's documentation for 30k replacement is in models with mechanical LSD (e.g. '03 Land Cruiser, 2005-2008 Tacoma TRD Sport)
https://assets.sia.toyota.com/publications/en/omms-s/MSTOY03_MS0003/pdf/MSTOY03-MS0003.pdf
https://assets.sia.toyota.com/publications/en/omms-s/07ToyMS_MS0004/pdf/07ToyMS_MS0004.pdf
On those models you typically have to squeeze in a tube of friction modifier in addition to the oil, else you get chatter from the clutch packs.

I suspect that's where the 30k "expert recommendations" come from, as those mechanics usually work on multiple Toyota models. "Inspecting" oil is hit or miss though - if the oil has gone acidic or its anti-foaming additives have degraded, it won't show up in a visual inspection.

 

This. Wear old clothes that you will throw out if any spills on you. Stuff is nasty.

 

I didn’t see it mentioned, but the GL-5 spec is critical. Most gear oils are GL-5, but GL-4 is out there and is not sufficient.

 

I will add that on a mostly freeway driven 2011 Limited, the diff oil that was drained after 120K(prev. owner) was remarkably clean and debris free. I found almost no wear material at all. Again, not condoning anyone go that long-just what I saw. I will do mine at 15K here on out. It's cheap and not difficult, just smelly.

 

Anyone ever look at or use eurol or ravenol from blauparts.com? They sell gear oil kits for front and rear diff and t case. 75-85 for diffs and 75 for the t case.

 

https://youtu.be/GB8LKDOpW6I?si=82uLpvcMZsGQ_uIt&t=41

https://youtu.be/OJZLMIl6XPo?si=5aHdvwFFdYzpVYiQ&t=367