I have 110 000 km on the 2.7 4runner .I`m thinking of changing my differential , transfer case and transmission to synthetic (amsoil or mobil 1 ) .But I heard that sometimes changing to synthetic ant higher mileage may cause problems . Anyone have any opinions ?

 

There should be no problems changing to synthetic, at least ive never heard any, if anything it will be better, less friction

 

Nope, wont cause any problems. Go with Amsoil - its great stuff!

 

No problems, go with Amsoil. Its amazed me in my car and all the fluids in my taco will soon be Amsoil. Get the membership so its cheaper also.

 

Depends on how good your seals are. I ended up with a mess on the truck going to synthetic gear lube because it went right past the seals. Ymmv.

 

I changed mine and refilled with Amsoil in the diffs, transmission, and transfer case. No leaks yet. Truck had 120,000 miles on it when I changed over.

The one problem I had was the shifting is a little notchy using the Amsoil. This has been discussed numerous time here. Some have changed over to Redline MT-90 in their transmissions to improve the shifting.

I reluctantly tried the MT-90 and would have to say it is a little better than the Amsoil on improving shift quality. It is still a little notchy when I first start off in the morning, but it seems to get better much sooner than when I had the Amsoil in it.

I still have Amsoil in the diffs and T case though.

Just something you may want to think about.

 

That is why I`m hesitant in changing to synthetic.

 

Let me clarify. The transmission with the regular stuff was the same way. The MT-90 may have even helped some.