Should you change rear diff gear oil sooner?

My Taco is approaching 30k, So I am thinking about changing the front diff oil, the rear diff oil, and the transfer case oil. After watching videos, I noticed the rear diff oil usually looks “dirtier”. (not a surprise at all, my truck drives 2WD, 99% of times, street driving.) So, should I change the rear diff gear oil sooner (next time), on a different cycle than front diff and transfer case?

also what brand gear oil do you recommend? Thanks

 

i changed my rear diff fluid using 90 weight Amsoil SG at 500 miles. it was pretty dirty and lots of metal shavings on the magnet. 22,000 miles and no diff whine yet.

 

I would just change all three of them at the same time, otherwise you’re going to forget if you did one, but not the other. 30,000 miles is perfectly acceptable if you fall into the severe use category. And, honestly, just about everything falls into the severe use category according to the Toyota manual.

 

Its usually easier to manage by keeping them all on the same cycle. You can change it at whatever frequency you like but for the most part it doesn't need changed that often, the magnets do their job.

 

https://www.tacomaworld.com/threads/3rd-gen-maintenance-maps-get-300k-miles.789809/

 

At 30K change intervals I changed to Lucas std petroleum based. Mobil1 got expensive.

 

yes, i would suggest changing it.

i fit the criteria and changed the diff fluid at about 15K miles. front was clean, rear was starting to darken but not too bad. no metal chunks or large flakes and the magnets did their job.

i used amsoil SG 75W90. it made no difference in diff whine or perceived performance. i really like the squeeze bags though, it made it easy and less messy. if i am not mistaken, valvoline also comes in squeeze bags.

 

I just changed my Front and Rear diff oil at 15K miles which I believe is severe duty and replaced it with the Valvoline

$29 75W-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75W-90 Full Synthetic Gear Oil in the squeeze packs.

After seeing a few folks struggle with removing the plugs in the front diff after they had been there awhile, I wanted to minimize the chance of stuck plugs. Mine broke free without issue... I had sprayed over them with RP-342 Cosmoline when the truck was new to seal of gaps and joints to prevent corrosion in the threads.

I found some metal debris on the rear diff that looked like more like machining shavings that were not flushed out of the casting when manufactured more so than a wear issue.
The front diff had a small amount of ferritic sludge which could be minor break-in wear or less than clean castings when assembled.

I deal with dirty castings on a daily basis in a manufacturing environment, so the appearance of the shavings and sludge was not surprising. It can be quite difficult to completely flush castings and make the machined surfaces "clean".



I've done some light off-roading, fishing holes, primitive camping and deep snow with the need for the rear locker a couple of times. Nothing severe and the 30k schedule would probably be more sufficient.

 

What he said ^

I do it every 3-4 oil changes or 18-24 months, I don't drive the truck enough to go by mileage on anything but I do have big tires, stock gears, and a lead foot. Been running Redline full synthetic 75W-85 and there's definitely gunk on the plug, which may be completely normal for all I know - but no blatant shavings or bits of concern that I can see. After reading ECGS feedback (someone posted it here, link on their website) I just swapped over to Lucas 85W-140 dino (half the price, allegedly better protection). No difference in "feel" compared to Redline and I never had a whine so I can't speak to that. I have a sample of the used Redline to send for analysis. I'll take a sample of the Lucas when it comes time and compare the two results.

Redline 75W-85 after 18 months:



At the end of the day, if you're actually taking the time to refresh your diff fluid, even on the "regular duty" schedule, you're probably doing more than the average bear, so high five.

 

just do it every 50k. Or 30k if it makes you feel better. Most people probly never change it, dont overthink it!

 

FWIW I did my diffs at 18k miles. Rear looked like new and front looked disgusting black color with tiny metal speckles.

Used redline fluid.

 

Note that if you have bigger heavier tires, carry excessive overlander gear all the time, heavy aftermarket steel skid plates, tow often, etc., that is added stress on gears.

Also if you frequent offroading in areas risking water contamination its good to check or change more.

For most people 30k-60k interval will be ok.

I did 15-20k on my 2nd gen that had heavy skids, big tires, steel bumper, shell, drove in mud and city traffic fairly often.

Remember that some people never change gear oil in diffs and still easily get over 100k without issue.

 

Great info, thank you

 

Changed my rear diff at 500 and again 14 days ago at 6700 miles. This last time I went with the oil recommended by ECGS which is Lucas 85W140. I’m now at 8658 and on the other side of the country. I’ve noticed that my rear diff is a lot quieter than what it was before.

Disclaimer: This is what I noticed in my truck when I changed the diff fluid. I’ve trusted several vehicles over the years to ECGS and that’s why I went that route. You may or may not notice what I did.

 

At 500 miles, then at 6700, just for switching to non synthetic oil?

 

I use to change my tundras differentials gear oil every 30k miles using amsoil 75w90 severe gear oil after towing quite a bit with the truck. Never had an issue for the 19 years I owned it. I saw my old tundra on the road this afternoon...still looking good.

 

So I did my rear diff at 60k. Too bad I drained it into my used oil container. Looked as clear as brand new. I was really surprised. There was not a hint of discoloration, nor were there any metal shavings on the magnet. Joked to my brother that I just should have poured it right back in. TC oil was a lot darker so I felt good about changing that. Front diff is coming up this holiday weekend

 

Changed mine at 170,000. That was 70,000 miles ago and everything still works fine.

 

I notice the first two differential oil changes on any vehicle I've owned were the most important, by the third change the oil I was draining out was as clean as what I put in. I had a 2006 Legacy GT Spec B I kept till 195,000 miles. Every 30K I did the diffs and transmission, at the 90,000 mile service all the gear oil was clean. I stopped changing it by 120,000 and it's still going today with 250,000+ on it.
Interesting thing I've read on here (more than once too) is that the front diff change at 30 on the Toyota is dirtier than the rear diff.

 

This is good to know. New to me. Thanks