ehuron

I have a 98 C5 with automatic transmission. It's time for servicing (90,000 mi). Most everyone says not to flush it just put in filter kit, so that's just what I'll do. Since I can only replace about 6 quarts of the original fluid, do I need to use same or can I add Amsoil synthetic and will it blend with original ok? Also, If not, can I use Dextron VI or Dextron VI synthetic? Also, would I be better off just adding the Dextron III, driving a few thousand miles and do it again?

Cutlassmaster

Amsoil is fine and will mix fine. I'd suggest that you replace filter and gasket, add fluid, disconnect cooler line at radiator, put a hose on it and into a container. Then start car and pump out old fluid while you continue to add new. Once you see and smell new coming out at cooler line shut it down. Reconnect line and top off fluid. Amsoil is very red and has a very strong smell. Very easy job especially if you have a helper when running car and adding fluid. I did it on jack stands and by myself with no problem. I noticed an improvement in quality of shift immediately.
GL
Chris

ehuron

Thanks for the info, but about how many quarts should I have on hand to do it your way? ehuron

Cutlassmaster

If I remember it was about 12 - 13 quarts. There is some loss of the new stuff but it really gets a lot of the old out. I would guess 90%+.
Chris

ehuron

OK, great. Almost all of it. I might have been sitting there with about 8-9 quarts. Thanks again. I can get started. ehuron