I am going to rebuild the 727 in my 72 D200 real soon. I use to just grab a middle quality fluid off the shelf for my servicings. But now, there are a metric butt ton of fluid options. I spent a lot of money getting good parts for this tranny and I want them to last. I do not want to spend money just for the sake of spending it though. So, I wanted to get some input from others who have some experience with these trannies and the different fluid options out there.
727's are bullet proof transmissions to start with. If you want it to last a long time I suggest you use AMSOIL's ATF fluid. You can't go wrong with a good quality synthetic right from the start. Helps keep it running cooler as well keeping it clean inside.
It helps with cooling? How? Under normal use, how often would I have to change it? Meaning, do I have to change it as often as the other stuff?
Oh, I have a deeper than stock pan and an external spin on filter. So I am packing a lot more fluid this time around.
Synthetic is designed to help carry away the heat better than conventional as well as hold up to higher temperatures and not break down. AMSOIL's ATF is recommended to be changed out at every 50k miles under severe duty, and 100k miles under normal duty. If you ask me most automatic transmissions see severe duty so changing it out ever 50k is a good time frame. With the extra cooler and larger capacity that you are using you shouldn't have any issues and will have a happy transmission for a long time.
So in my way of thinking, if the synthetic stuff lasts longer, the extra expense pays for itself with a longer service life. Who carries Amsoil?
Yes, the fact that you can go longer on drain intervals makes up for the extra expense of the synthetic. Send me your address in an PM and how many qts you want and I can get you a quote delivered to your door.
Actually, I do not know how much it takes now. With the added cooler, deep pan, and spin on filter it takes a lot more now.