Thoughts on differential oil change interval

[mrdctaylor]

I have a 2002 Toyota Tacoma 2WD V6. Love the truck. I bought it brand new and it is still my daily driver. I only drive on roads, and most miles are highway miles. I change the oil with synthetic regularly. I drain/fill the transmission every 30K miles. I change the coolant regularly. In short, this is a well-maintained vehicle. However, I've only changed the diff oil once. In 2011 at 131K miles I drained the diff and refilled with Mobil 1 75W90LS diff oil. When I did it, I remember thinking this is probably the only time I'll ever have to do it. Now it is 2017 and I have 205K miles on the truck. Honestly, I feel like I could probably go the rest of this truck's life without fooling with the diff again. Then again, it isn't expensive or difficult to do and I plan to keep this truck indefinitely. Thoughts? I know most people NEVER change their diff oil, so I feel like the fact that I changed it once and used synthetic is at least better than that.

 

[Schmoe]

Changing the diff. oil was something nobody I've ever known to do "back" in the day. However, it seems to be more common place now. I did the same as you on my F150, but at about 80K miles because I wanted to put a chrome cover on it. I also dropped the exact same oil in it as well and said this is the last time I do this so I made dang sure the gaskets and permatex was lined up correctly. With that, I'm not even thinking twice about it. I'd leave it alone since you did already change it out and the M1 stuff is a lot better than the factory stuff. If you got 200K already, I'd be thinking if I hit 300K, I'd be looking at replacing those gears if I was going to keep it and then I'd have to open it up anyway.

 

[Panzerman]

I would change it. That seems reasonable, cheap insurance.
All manufacturers are different. Ford claims factory fill for life while my Dodge with the Lifetime warranty requires fluid change every 15,000 miles with Full Synthetic 75w90, which is insane. It looked terriable the first time after that it looks new. I've fixed the books several times especially when using Amsoil or Mobil 1 synthetic even after 30,000 looked new.

 

[Linctex]

I've never changed the diff oil in a passenger car, unless I was swapping gears or something.

My trucks that carry heavy loads and do towing get 50,000 mile differential oil changes.

 

[dparm]

I think an interval of "every other transmission fluid change" is probably fine.

 

[Alex_V]

100K interval. If you changed it now you'd be close, and just keep doing that. May not have been commonplace back in the day, but how many wheel bearings could've lived how much longer if they were running in good lube instead of the burnt up, shimmery, black goo that drains out of a diff. that hasn't been serviced for 20-30 years?

 

[555]

Posi-traction, Traction Lok, remember those names? I don't know if your Toyota has a limited slip differential, also don't know if it requires an additive for the limited slip diff. Would tell you in the manual.

 

[tomcat27]

The first change is the most important and should be done early. After that, every 100k sounds good.

 

[Kestas]

Some time ago it was posted that differentials are broken in at around 5000 miles. That would be a good time to remove the break-in fluid to reduce damage to the bearings.

At work I'm seeing a troubling trend of tested bearings not lasting the distance for differentials, transfer cases, and transmissions, where lifetime fill is specified. The failure mode generally stems from debris denting. Auto manufacturers are asking bearing manufacturers to come up with bearings that can withstand debris denting. I personally see this as a backward way to solve the issue. An early change in the fluid would go a long way with having a reliable product.

Unfortunately this is a hard sell to the consumer, who basically wants a maintenance-free car that doesn't have to make special trips to the shop.

 

[Bgallagher]

With a Full Synthetic oil you can easily go 50k between changes but with a higher mileage, well maintained vehicle I would stick with the 30s. I always felt that clean fluids help prolong life and it seems like your old gal has some age but is still running well. Treat her right

 

[barkingspider]

I would change the diff oil now since it's a keeper truck for you

 

[Dyusik]

My jeep saw it's first front diff change at about 180k, rear 170ish (leaky seal). Both gear sets were fine, bearings and all. Front was about half a at over filled...with water.
Had a J30 with 180k+ on FF, like many on other cars on the road.
My buddy's XL7 rear end was rather black and filthy at 130k,.
In the IS, I dumped the FF at 35k, clean oil with filthy magnet. Will do again at 100k, and never after. That is what I call diff OCD over-maintenance.
I'd every 50k in a differential with a locker or Posi with clutch debris. Otherwise a couple of times in it's lifetime will be fine for a non towing vehicle.