I know the Synthetic / Organic motor oil debate has been beaten to death around here but wondering about what everyone thinks about Transmission fluid. I switched the motor oil to Synthetic but wonder if I should do the same with the Tranny. Your suggestions/experience is appreciated for my 4WD '02 , Thanks

 

The transmissions only real enemy is heat. Heat kills the fluid and then the tranny goes. Synthetics take heat much better. Dexron VI is synthetic and compatible with Dex III. That's what I use.

 

I think its more important to have synthetic ATF than it is to have synthetic motor oil, if I had to choose between one or the other.

 

Amsoil Universal. Only stuff I'll ever use. Worth every penny

 

If you wanted to convert from dino ATF to synthetic, should it be okay to mix the two as you're swapping them out?

I don't really want to drop the pan right now, but I was planning on draining what I can get from the plug in the pan, then flushing out the transmission via the transmission cooler line (filling at the dipstick) a quart at a time until I'm getting new fluid coming out of the cooler line as described in THIS WRITEUP. Obviously, that would have the two oil types mixing. I figure this is as good a time as any to go to synthetic, since it's got a better working temperature range than dino oil.

 

i was considering going synthetic with mine but decided to use regular tranny oil. i have 160k on my 4runner and its never used synthetic, and i read things where its not good to switch to synthetic with high mileage. is this true??? if not i would really consider it. i just did a drain and fill with valvoline max lift oil and my 4runner shifts very smooth. don't want to mess anything up. if its not broke then why fix it right.....

 

Most of the arguments about synthetics in higher mileage engines concerns whether or not it creates oil leaks or makes present ones worse. That's a whole other argument. I've switched my two trucks over and haven't had any issues yet... But considering that argument on transmissions the same doesn't really hold true. Do transmissions have leaks? Rarely. As mt_goat stated earlier and I agree, synthetics in transmissions are even more important than in engines. The main reason to me is because of the length between changes. If you changed your trans fluid every 5K dino oil would be fine I'm sure.

 

I changed everything over to Royal Purple when I bought mine at around 128K. Never any negitive results from it. I personally have a hard time believing any kind of oil \ fluid (reg or syn) is BAD for your engine \ drivetrain. It's all personal preference.

Unless there's a molecular scientist on here whose lab has tested and willing to post results it's really up to you. Just normal maintance is the biggest, best way to make your Toy live a long health life. But I'm with the others in believing Synth is better then Normal ATF Fluid due to heat.

 

really considering it. have to add that i live in arizona so for about 5months its 100+ degrees out here. how often would you change synthetic or regular if living in arizona

 

Like psraff said, it's really all personal preference. hdoggie I know you are installing a cooler but I'm not sure if that is just for peace of mind or because you tow. If you tow during the summer months there... well, I'll leave it up to you. If you stick with dino I'm sure you'll be fine with the cooler. Maybe doing a drain and fill every time you change your oil would be the way to go?

 

well for peace of mind of not having my radiator bust and pour to the tranny. i am doing the b&m install later this week. i do not tow. i do however live in az so that might add to increased temps. good idea on the drain and fill every oil change. the valvoline maxlife is pretty cheap at walmart so ill stick to that. thanks kball. i will post pics of my install when i do it. hey kball were talking on both forums as we speak. pretty funny. take it ez. btw, i used to live in cypress, ca which is really close to you. i've been in az for about 2.5 years now. take it ez

 

Redline D4, or Castrol Import Vehicle ATF if $$$ is an issue, are great choices.

 

switching to synthetics might make your tranny leak but its worth the added protection and performance.

 

Valvoline Max Life is a good and fairly cheap ATF (>$20 for a gallon from Advance). I am doing the drain pan every 2 weeks x4 changes. At 150,000 (currently at 128,xxx) I am planning to do drop the pan and change the filter.

Amazingly simple maintenance with the only difficult part being to make sure you clean all the old FIPG off and get a good seal when you put the pan back on.

Chris

 

I was wondering about Max Life myself. It's considerable cheaper than something like Amsoil, but hopefully better quality than Wal-marts Dex 3 Supertech stuff. I think it's what I'll start using. It is NOT a full synthetic though right?

 

the castrol is a regular base synthetic blend.The amsoil is great as is the mobil 1.On my 4runner I went with the blend and a external cooler.

 

The thing about synthetics is that the Dyno oil makes the seals swell and it is absorbed more into them. With the synthetic it doesn't make the seals swell as much and there for is why the leaks start to appear. But the new syn is suppose to not do this as bad. I would switch mine over if i was going to change it. I switched the motor at 120k to Mobil 1 full syn and my valves started leaking. But i dont lose more than QT between oil changes so no need to fix it yet. Waiting til i hit 200k to really mess with the drive train....

 

i use Dexron VI and love it i noticed a little bit of a difference when i switched like it shifted smother deffinately would use synthetic bc u only change it every 50,000 miles or so and if u havent done so already i would add an aftermarket tranny cooler and bypas the one in the radiator thats my $.02

 

My friend has been using the MaxLife ATF DEX/MER in his T100 for the past year and a half with good results. He called Ashland (Valvoline) and they told him it is a full synthetic, yet nowhere on the bottle does it state such. Autozone sometimes has the gallon jug for $17 on sale.

I have seen Castrol Import ATF for $12/gallon at Wallyworld on sale from time to time. It works well for me.

 

i get the valvoline maxlife at walmart...its like $3 a quart. so only about 13bux for a gallon. good price and it works fine for me. i thought using the dexron Vl (i thought next was dexron lV) was not a good idea on our 4runners since it was for the 4th gen 4runners. read about that somewhere else.