How soon, rear diff oil?

How soon are you all changing the rear diff oil?? Granted I only have 1200 miles on my 2013 but ive built a few Ford 9" Rears in my day and It was always a must to change the oil after 500 miles. I know the manual says something like 50k (dont quote me on that, I cant remember and dont feel like going to the garage) I figured id change it soon since its past the "break in period" Manual says dont tow ect for the first 1000 miles... Surely there are some break in particles floating around in there..

 

Yes there are, but fortunately the drain plug has a really big magnet that keeps them out of the lube.

Toyota said never under normal use for my truck because it's synthetic from the factory, but I call BS, the stuff is going to gather water at some point.

If I would have bought my truck new, I'd have changed the rear end lube for the Redline I use now somewhere around 5k-10k miles, when I'm sure the break in wear is all but over, then every 30k-50k after that. Just my personal preference.

 

Good to know about the magnet, makes me feel better. most of my knowledge is from older fords (9" &8.8s), with no magnets or drain plugs maybe I'll change it at 5k..

 

Do you plan on keeping this particular truck forever? than you don't need to replace it untill 50k. If you plan on selling the truck in 5-6 years than you don' need to replace it at all...LOL I did mine for the first time at 100k-7 years and it came out clean and still red color, no shavings. The truck was running good before the change and still running real good now. A waste of time and money if you do it at 5k, but hey it's your money and time. Good luck man. Normal use though I don't offroad or pull heavy stuff.

 

I had Toyota replace it when I blew up my diff... Apparently there were spider gears floating around the oil

 

Haha, yea hopefully for a very long time. Could be a waste i spouse but just for pace of mind and a chance to clean off the magnet and see the oil. Wouldn't hurt.

 

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I changed mine at 50k and it still looked new. I tow a decent amount and plan on this truck lasting so it will probably get changed every 50k

 

While I don't know what fluid is in there from the factory, I would change it now.

With any re-gear of a diff most companies recommend a 500 mile oil change.
Why not follow that and simply change it now for a little extra insurance?

 

I believe it's every 30,000. I tow a boat so every 15,000 miles. It's cheap and easy to do.

 

When my truck was 6 months old, I drove into a muddy bog, 1/4 mile long... upon return home from that Baja adventure, Toyota inspected my differential, and it was water contaminated... milky... so the fluid was changed... and I performed the rear differential breather mod... DO IT (photos in signature link below).

I had it changed again at 40,000 miles and the fluid was normal looking for 30,000+ miles on it, and no metal on the magnet. I changed it to Mobil 1 (75/140 in the rear)... and 75/90 in the front and transfer case... which looked like new oil in it!