Transfercase and rear-end should be changed every 30k-50k, 2-4yrs max, depending on driving style, after the factory fill has been dumped preferably early. Stick with a synthetic gear oil If you've never changed it, you are overdue. Get them changed. Their are some defective trans:xcase seals and if your xcase drains mixed gearoil/ATF, then you better get it fixed ASAP and while under warranty. This is one reason why I recommend an early change out(to remove break in wear), and another one definitely before the warranty expires(to inspect for fluid mixing).

The transmission's ATF should be flushed too. You'll need ATF WS or an equivalent from Amsoil, Redline, Amalie, Maxlife....

I'd changed the coolant too. You can use Zerex Asian, Peak Global, or the Toyota Pink antifreeze. These are extremely long life antifreeze but I've seen too many failed cooling systems due to neglect. IMO, its better to change it out then have a failure because you never made that effort.

4wd is full time and you use it EVERY time you drive your vehicle.

 

Just fyi, I had the transfer case fluid and rear diff fluid changed at 45k miles. The stuff came out very dirty. Plus the magnet attached to the back of the drain plug had all sorts of metal shaving on it. I have now switched to changing the fluids every 15k. It is way cheaper to change the fluids than to replace the transfer case and/or rear diff.

 

15k is very aggressive, maybe try 30k?

 

I think everyone can agree that the recommended change interval as stated in the manual is just too long of a period. Having said that, if you choose changing at either 15k or 30k, well that is up to you and your driving style, conditions, etc.

 

I see we have another group of automotive engineers second guessing Toyota....who of course didn't do any extensive duty or end of life testing before making recommendations. And of course, everyone knows that the color of the fluid and how much snot is on the magnet is a valid excuse to 1/2 or 1/3 the manufacturers interval recommendations so the right color is maintained... :disappoin

 

guys

looked at maintenance log and it says the differentials, transfer case fluids change required "while driving with towing". few mechanics are saying these are not required unless i am into towing boats or such activities or going off roads etc. i mostly use it as my commute car (30 miles per day) and maybe once or twice an year long drives, camping etc.

 

Since you don't tow, coolant is 100k miles. It's the SLLC, so don't ever add water or coolant that doesn't meet the requirements in your owner's manual. Most will just recommend buying Toyota's SLLC (super long life coolant) which is already premixed. Tranny is also 100k miles (it uses WS fluid).

While the maintenance guide tells you when to change the front/rear differentials and T-case when towing, it never tells you to change it when you don't tow. Toyota dropped the ball years ago on this subject (even for the trucks). They're using regular gear oil. The standard then is to change them every 30k miles. Some like to do it at 15k just like some people still change their oil every 3k miles.

 

I changed my diff fluid at about 5k originally, and have had Amsoil in there since (currently 70k). I recently had the front x-fer case leaking oil, and Toyota covered the repair under warranty. While they had the front x-fer case out, they also replaced the tranny seals under the TSB that covered the issue, even though it wasnt leaking. I guess they figure might as well do it while were in here? Total cost for parts was about 50 bucks, labor 950.00, and 14 hours worth of work, YIKES!

I do believe Toyota lists the non towing interval in the maintenance schedule for the x-fer case.

As for transmission, my brother works on automatic trannies all day at his job. He basically said that the majority of tranny issues comes from a leaking tranny that the fluid gets to low, and the clutches burn up. As for these transmissions he recommended just waiting till the 100k to change it. I reguarly check the fluid level, and the color, and even before the seal change it was still bright pink, and did not smell burned.

He also recommended that when it comes time to change it, take it to Toyota as they have the proper flushing system, and could probably do it the best. The cost isnt unreasonable from Toyota, so thats the route I would go. Luckily for me, when they pulled the tranny seals, they also changed the fluid as noted on the repair ticket.

As for antifreeze, I would change it at the recommended Toyota interval.

One thing I find funny is that everyone gets all freaked out about all these fluids, but nobody usually flushes brake fluid at the recommended intervals. This fluid is probably more important in my opinion that the other fluids(in my opinion).

Just my $.02!

 

I changed my diff fluid at about 5k originally, and have had Amsoil in there since (currently 70k). I recently had the front x-fer case leaking oil, and Toyota covered the repair under warranty. While they had the front x-fer case out, they also replaced the tranny seals under the TSB that covered the issue, even though it wasnt leaking. I guess they figure might as well do it while were in here? Total cost for parts was about 50 bucks, labor 950.00, and 14 hours worth of work, YIKES!

I do believe Toyota lists the non towing interval in the maintenance schedule for the x-fer case.

As for transmission, my brother works on automatic trannies all day at his job. He basically said that the majority of tranny issues comes from a leaking tranny that the fluid gets to low, and the clutches burn up. As for these transmissions he recommended just waiting till the 100k to change it. I reguarly check the fluid level, and the color, and even before the seal change it was still bright pink, and did not smell burned.

He also recommended that when it comes time to change it, take it to Toyota as they have the proper flushing system, and could probably do it the best. The cost isnt unreasonable from Toyota, so thats the route I would go. Luckily for me, when they pulled the tranny seals, they also changed the fluid as noted on the repair ticket.

As for antifreeze, I would change it at the recommended Toyota interval.

One thing I find funny is that everyone gets all freaked out about all these fluids, but nobody usually flushes brake fluid at the recommended intervals. This fluid is probably more important in my opinion that the other fluids(in my opinion).

Just my $.02!

x2 on the brake fluid! If you go 100K miles on the original fluid, you'll probably have air in the lines at the rear brakes from age/deterioration of the fluid (ask me how I know this:facepalm.

On the tranny fluid service comment, you may still have to shop around for a dealership that has the proper equipment. Over on the Tacoma forum, a lot of people are told by their dealerships that they do a drain/fill only and don't do a flush. Those dealerships usually don't have a separate dedicated WS fluid flush machine.

 

Its not air Im worried about, its water in the brake fluid.

As for the tranny, i guess a drain/fill would work. I guess its really no different than the engine that also has some oil left in places other than the pan. My concern would be the amount of fluid the converter holds. But I guess if your overly paraniod, you could drain/fill the tranny every 30k or so, and that would definitely keep the fluid clean.

 

you could drain/fill the tranny every 30k or so, and that would definitely keep the fluid clean.

I'd rather go this route vs flush and fill. :thumbsdow