Transmission Fluid T-ii Vs. T-iv

Graham · October 29, 2008

Hi,

I have black transmission fluid, caught it in time because the car still drives. Do I put in Type T-IV (which I can buy) or Type T-II (which my dealer has in a bulk tank).

The difference is I have to pay a dealer to "change transmission fluid in a Lexus SC-400" vs. "I change the transmission fluid in my driveway."

Thanks for the input!

landar · October 30, 2008

Normally I like to perform maintenance myself. However, if the fluid is black, I think I would let the dealer

handle this one, this time. Complete change of fluid, filter and any adjustments that need to be made.

After that, you can do the 2 quart driveway changes and not let the fluid get to the filthy state.

AZ Mike · October 30, 2008

Which transmission fluid does your owner's manual call for? Type II or Type IV? I am only familiar with Type IV. If your owner's manual calls for Type II, did Type IV replace Type II and is it backwards compatible? I do not know anything about Type II, so either you need to do a little more research, or someone else needs to chime in.

More information than "I have black transmission fluid" would be helpful:

Is this car new to you? I.e., do you know how many miles are on the vehicle since the last transmission fluid change?

How does the transmission function? The fact that the fluid is dirty is significant, but of more importance, how is the transmission operating? I.e., does it shift smoothely at appropriate rpms, etc.?

If the transmission operates properly, I don't see anything wrong with doing multiple short interval drain and fills to refresh the fluid. I have never dropped the pan on my transmission (drain and fills only), and don't know about the filter; I can't find mention of the transmission filter in my owner's manual maintenance supplement. I DO know that with some vehicles (don't know about Lexus), that a machine operated reverse flush of really dirty transmission fluid can do more damage than good to the transmission. I don't even know if Lexus does reverse flushes, but it is worth asking.