Differential OCI

Oldswagon · Sep 4, 2019

Toyota recommends 30K mile or 50K km OCI for the differentials on my Tundra. They recommend 75w85 but I have been using 75W90 synthetic. Since with the transfer case it takes nearly 8 quarts of gear oil, it's not cheap to replace all this oil. There is no mechanical LSD or lockup in either diff.

Do Toyota's OCI seem correct even if using synthetic lube? I have run RP in past, and just filled with Castrol Syntec this last change.

LotI · Sep 4, 2019

That does sound like a short interval. You could always send a new & used sample to be analyzed to see if it's really necessary.

The Dana axle in my E450 goes longer than that, in a 14k pound truck.

SwampSurvivor · Sep 4, 2019

Well there's a lot of vehicles that make it to the junkyard with 300K miles on the original gear lube ...

30K mile seems reasonable to me.

wagsrk08 · Sep 4, 2019

Originally Posted by Oldswagon
Toyota recommends 30K mile or 50K km OCI for the differentials on my Tundra. They recommend 75w85 but I have been using 75W90 synthetic. Since with the transfer case it takes nearly 8 quarts of gear oil, it's not cheap to replace all this oil. There is no mechanical LSD or lockup in either diff.

Do Toyota's OCI seem correct even if using synthetic lube? I have run RP in past, and just filled with Castrol Syntec this last change.

I would think it would be in your best interest to maintain the Toyota OCI in your differentials & transfer case (transmission too). Earlier this year I changed my front/rear differentials with Redline 75W85 GL-5 gear oil (2012 Tacoma 4cyl 4x4). Used Redline MT 75W90 GL-4 in both manual transmision & transfer case. I went with what Toyota recommended on oil weights & GL ratings. Since I never tow anything with my Tacoma (30,000 mi towing OCI), I didn't do these changes until 80,000 miles. All the fluids looked great other than front differential which had a light tint (water or broken down). Next time around I'll change @ 45,000 miles since fluids looked great and I still won't be towing. And yes, Redline products are not cheap. But I'll use them again.

ARCOgraphite · Sep 4, 2019

I do a early 15K - 20K change and then it's in till 100k.

Unless its under water it will be fine.
(some guys launching craft dip their 3rd member in the ocean or lake).

You can always pull the plug and look at the magnet.

Are you sure that's not "INSPECT" in the rec service manual?

I would think a 30K would be severe service.

Like BAJA forerunning.

2004tdigls · Sep 4, 2019

with such a short OCI I would just use a dino 80w90, even a Canadian Tire product that is GL5

https://www.canadiantire.ca/en/pdp/motomaster-extreme-pressure-gear-oil-80w90-946-ml-0280239p.html

Snagglefoot · Sep 4, 2019

I looked up a couple of sources. A 2015 Toyota Tundra owners manual did not discuss it. A Florida dealer mentioned 30,000 miles but that's like asking a barber if you need a haircut. Many manufacturers suggest either 50,000 or 100,000 miles. Can anyone show an excerpt out of a Toyota owners manual?

Donald · Sep 4, 2019

Most transfer cases I have had in a vehicle took ATF not gear oil.

I use Amsoil SVG in the diff and Amsoil ATF in transfer case.

You can always sample and UOA.

khittner · Sep 4, 2019

I've generally done 30K changes for the manual transmission (Aisin 5-speed) and differential in my '95 Dakota since new (236K miles), using Mobil 1 75w-90. I lengthened the mileage when I went with Amsoil SVG 75w-90 to 50K miles. This last change, I just went with Super Tech synthetic 75w-90. The transmission shifts as smoothly as ever, and the rear end is essentially silent. I'd stick with your 30K interval, and use Super Tech, if the oil's cost is an issue.

ZebRuaj · Sep 4, 2019

I just bought and serviced an 08 Tundra. No history of driveline fluids in its 108k lifespan. Put in Supertech Syn 75w90 in everything and didn't think twice. Will probably do it every 50k moving forward.

If yours sees hard towing or water crossings, change it out more often.

benjy · Sep 4, 2019

changed all drivetrain lubes to redline in my new to me 2011 frontier SV with only 28 thou on it, + used the dana recommended 75-90 real synthetic in the dana-nissian rear picked up about 3 mpg's!! old lubes looked poor. nissan like many OE's use costlier but cheaply blended semi-syn lubes

Dave9 · Sep 4, 2019

100K mi then every 50K mi
Half that for severe service, particularly towing in hot weather or while driving like a maniac.

Oldswagon · Sep 4, 2019

I should clarify that this is a 2008 Tundra with over 140K on it and I have owned it for most of its life. So warranty is not an issue. I want to use synthetic because of the cold weather I see, as cold as -40 on a rare occasion. It also doesn't see heavy towing or get dipped in the lake. When I launch my boat I never go that far into the water.

I just wanted input on whether I could extend the Toyota recommended interval. I would think synthetic would offer I increased longevity. ÃŒ admit, I did run the front diff and transfer case about 50K miles and they seemed pretty clean when I dumped them last week. I have dumped the rear end every 30k, because it gets used a lot more. This last time the oil looked almost new coming out. So I was thinking 50K might be good for both.

And yes, I owned several vehicles in the past where the dinosaurs gear oil was never changed.

Originally Posted by wagsrk08

I would think it would be in your best interest to maintain the Toyota OCI in your differentials & transfer case (transmission too). Earlier this year I changed my front/rear differentials with Redline 75W85 GL-5 gear oil (2012 Tacoma 4cyl 4x4). Used Redline MT 75W90 GL-4 in both manual transmision & transfer case. I went with what Toyota recommended on oil weights & GL ratings. Since I never tow anything with my Tacoma (30,000 mi towing OCI), I didn't do these changes until 80,000 miles. All the fluids looked great other than front differential which had a light tint (water or broken down). Next time around I'll change @ 45,000 miles since fluids looked great and I still won't be towing. And yes, Redline products are not cheap. But I'll use them again.

So you tell me to stick to 30K OCI, but you did extend your and will continue to do so?

wagsrk08 · Sep 4, 2019

Originally Posted by Oldswagon
I should clarify that this is a 2008 Tundra with over 140K on it and I have owned it for most of its life. So warranty is not an issue. I want to use synthetic because of the cold weather I see, as cold as -40 on a rare occasion. It also doesn't see heavy towing or get dipped in the lake. When I launch my boat I never go that far into the water.

I just wanted input on whether I could extend the Toyota recommended interval. I would think synthetic would offer I increased longevity. ÃŒ admit, I did run the front diff and transfer case about 50K miles and they seemed pretty clean when I dumped them last week. I have dumped the rear end every 30k, because it gets used a lot more. This last time the oil looked almost new coming out. So I was thinking 50K might be good for both.

And yes, I owned several vehicles in the past where the dinosaurs gear oil was never changed.

Originally Posted by wagsrk08

I would think it would be in your best interest to maintain the Toyota OCI in your differentials & transfer case (transmission too). Earlier this year I changed my front/rear differentials with Redline 75W85 GL-5 gear oil (2012 Tacoma 4cyl 4x4). Used Redline MT 75W90 GL-4 in both manual transmision & transfer case. I went with what Toyota recommended on oil weights & GL ratings. Since I never tow anything with my Tacoma (30,000 mi towing OCI), I didn't do these changes until 80,000 miles. All the fluids looked great other than front differential which had a light tint (water or broken down). Next time around I'll change @ 45,000 miles since fluids looked great and I still won't be towing. And yes, Redline products are not cheap. But I'll use them again.

So you tell me to stick to 30K OCI, but you did extend your and will continue to do so?

Your opening post was vague. Now we know your vehicle is 11 years old with 140,000 miles. You don't heavy tow, and you've owned your Tundra most of it's life. As far as I knew from get go your vehicle was fairly new, possibly under warranty and low miles. With this new information you've provided I'd extend it out to 45K. And yes use synthetic fluids. My Toyota owners manual recommends synthetic gear oil.

FA_WRX · Sep 4, 2019

I change mine at roughly 30K OCIs as well. I dont think it hurts to keep fresh fluid in there.

ka9mnx · Sep 5, 2019

Both my Ford manuals say filled for life. Severe service 150k. I've been changing everything at 60k with synthetic for many years. Always comes out looking new. Seems a waste at 60k. Recently switched from Mobil1 75w-90 to SuperTech syn 75w-140 and like it! The 4Runner manual says 30k but it's on the 60k schedule.

Differential OCI

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