Just bought an 02' T4R 3.4 L with 110k all highway and never towed anything. Oil has been changed regularly and I believe the rear diff fluid too. But as far as I know, the tranny fluid, txfer case fluid and front diff fluid have not been changed.
Question: Would you guys put synthetics in this vehicle? Which boxes would you put it in (all or some)? No leaks. How much fluid do I need for all 3 boxes total?
I was thinking Valvoline Syn power 80w90 for txfer case and diffs (might as well all three at the same time).
The tranny: Fluid a little orange but still red. Thinking of next 3 or 4 oil changes just doing draining and filling w/ Prestone Dex III then every 15k after that. I was reading about how people suggest draining and filling if it has been a long time since fluid was changed / flushed. Suggestions?

 

You might wanna consider Amsoil, It's not cheap but I would recommend it... at least for you rear diff/x-fer case.

This may help:
http://www.top4runners.com/ja/synthetic.html

 

I would do synthetic..80-90..need 10ish quarts to do all 3,rear/front diff and transfer. I would also manual flush with synthetic dexIII,drain pan,fill,then manual flush using the cooler lines and fill through the dipstick..2quarts at a time........Oh,and bypass that radiator cooler with a nice plate and fin type(search)..cause if that leaks internally its all over if you don't catch it fast enough.

I use one of these for the gear oil replacement..Makes things easier:
http://www.amazon.com/Industries-Sta.../dp/B000CPIOBA

 

10is quarts? I am only seeing about 6 quarts:

http://www.top4runners.com/ja/synthetic.html

Amsoil is about $9 / qt. I don't want to buy more than I need, but I have never done this before.

You guys would put synthetics in this vehicle even though this stuff has never been changed in 110k?

 

How often are you really using your transfer case? I engage my 4WD about 6 times a year, so regular gear oil will do just fine.

As for the transmission, I have a 1999 Limited with 246,000 miles on it. I flushed it once at 220,000 and I have always used Toyota approved non-synthetic ATF. Everything is running perfectly.

PS, if your radiator oil cooler ever goes out on you, you'll end up with the dreaded "strawberry milkshake." (ATF and coolant mixed). If this has not happened........it probably will sooner or later

Then you will be glad you aren't dumping and replacing a lot of expensive Amsoil.

 

Just bought the truck. Don't know how often I will really be using my txfer case. But aren't both diffs always turning?
I wasn't planning on spending $200 on tranny and diff fluids. I got the Amsoil for the diffs / txfer case for $9 / qt. Already bought that.
Does that ruin the tranny if the "stawberry milkshake" happens?
Is it just best to replace the radiator with the tb/ wp?
Sorry for all the questions, but I am new to 4WD vehicles, so thanks for everyone's input.

 

There have been transmissions that survived the milkshake, but not many.
External cooler is probably cheaper than replacing the radiator, I'll probably drop one in at 120K.

I would do an ATF flush, it's very easy... or you could do the more thorough, but pain-in-the-a$$ pan drop filter clean/replacement.

Don't forget to flush the coolant.

 

My cooler went bad and the ATF and coolant mixed. I caught it early and had the trans flushed, all 12 quarts or whatever the amount is. It's a lot.

The trans developed a hesitation for about a month. I changed the ATF again and that fixed it. Those are amazingly tough trannies.

 

My bad on the fluid quarts...

If I had my choice,I would go dino on all the fluids and take the savings and spend it on an external bypassed radiator cooler....Really

Might be the best $100 spent on your vehical..

I have this one installed:
http://www.importperformancetrans.co...xj1eSj68xXqzXa

 

i can support the AMSOIL claim also. My old old R150 has been drained and out of my truck for over a year and you can still feel the oil sticking to the gears--whereas my newer R150 that came out of my newer 4Runner and is drained doesnt feel like it has any film left on it.

I have also been doing some research on Schaffer Oils

 

Does anyone change the rear diff breather to prevent the rear axle seals going bad?
Question about the tranny cooler:
In Utah, it doesn't get much below 0 if ever but it does get above 100 a few times during the summer. Should I put the bypass valve and temp gauge in the cooler when I do it? Or just leave the cooler (bypassed completely from radiator) as is?

 

The breather will not prevent the axle seals from eventually going bad, however, if your breather is clogged it can allow pressure to build up in the rear differental and prematurely cause the seals to fail.

I occasionally check my breather to make sure it's functioning properly, but I have yet to replace it.

 

http://www.4runners.org/

I know you have a Taco but there is some good info on 4runners.org.

 

I don't have a Taco. I have an 02 T4R. Thanks for the link though.

 

Update:
I changed the diff fluids, and txfer case. I also changed the oil that oil filter is a pain in the a$$. Next is the timing belt / wp. Anyone in Northern Utah mind helping?

 

Synthetics all around! I really like the extended drain intervals and the protection, but costs more $$

 

how do u check to see if diff breather is working or not ?

 

Take it off and blow through it. Should be easy to blow out of it, hard to blow into it. Take the opportunity to extend it higher with some fuel line, like up to the gas fill cap. Write ups abound on this mod.