How often should I be changing Rear Diff fluid?

30k severe duty, 60k normal duty, or option #3 every 30k with Walmart super Tech 75w90

 

It’s diff fluid in a Toyota truck. Toss whatever is cheap in there and drive.

 

Not a rear diff, hell not even a Toyota, but it seems like this fits here.

Guy I used to work with -- his ex-father-in-law (logger) would buy a new dodge pickup and never change the engine's oil. If it got low he would add a quart, but no oil changes, ever. When it wouldn't run any longer he would buy a new truck. Made no sense to me but I guess it did to him.

 

Hunter_bick.. I just serviced mine today for the first time with Valvoline syn 75-90. It's a 4x4 so I did front and rear diffs, trans and transfer case. 40,500 miles. The rear end oil was by far the dirtiest and most contaminated from wear, apparently.

My thinking is that eventually these things will fail, but I don't want it to be because I didn't maintain it.

 

So oddly enough I ended up asking this exact question to the lead service department tech at my local Toyota dealership last week.

He recommended that diff. fluid be changed every 15k miles. He also mentioned he follows this with his own trucks and has never had any issues. For my 2014 SR5 he recommended saving the $80 (that's per diff) and doing it myself.

Based on my own knowledge and background I think this is a little soon especially if you're just daily driving paved roads. Now if your hauling or doing some serious off roading, this might not be a bad idea.

Hope this helps some!

 

If it makes you feel any better I’ve been doing it every 30k with the cheapest stuff I can find and I’ve had no issues in 3 Tacomas with 600k cumulative miles. Hauling, towing, and offroading in extreme heat and cold. Never any differential issues. Usually wallyworld Supertech fits the bill because it’s cheap and almost always in stock.

 

Thanks for sharing your experience on this. Based on what you said and the fact that I'm not pulling or otherwise putting additional strain on mine, I'll stick to at least 30k miles before changing.

 

It could probably go longer but I typically do it for good measure since it’s an easy and cheap procedure. When I was in Alaska I did stick with

$30 75w-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75w-90 because of its better properties in extreme cold, otherwise I’ve used other weights with no adverse effects

 

Mobil 1 is what I use. That seems to be the brand.

 

Depends on what oil you are using and the use of your truck.
I change every 60K because I use synthetic Mobil 1. Amsoil makes a severe gear that lasts 100K.

 

Whatever makes one feel comfortable is good. It's hard to imagine how rare any diff. problem is ever even heard of. Most common problem is a leaking seal. Just guessing, probably 80% of folks never change diff. fluid, unless the stealership talks them in to it, & it's very very very hard to find anyone who has ever had a diff. problem. Do whatever makes you comfortable, but in my 66 yrs, I've never heard of a diff. that went bad per. lack of fluid change.