Transmission Fluid

[Mike and Joanne Stimmler]

I know that Catalina says you can use either Ford AFT or GM Dexron II fluid as long as you don't mix them but what if you don't know whats in there now. Would you need to flush the Trans to make sure you don't get a mix? Is there a preference of one over the other. Thanks.

Mike

[Stu Jackson]

It shouldn't matter, because when you change the fluid you drain the transmission anyway.  It only takes a small amount of fluid so you're not losing much of anything.

[Ken Juul]

The newest fluid on the market is Dexron III.  It is supposed to compatible with either the Ford ATF or the DII.  The trans uses a little more than a cup of fluid.   I would suck out the old, squirt it into a plastic water bottle to check the condition.  Add a cup or so of clean fluid, rotate the shaft a bit to work it around, suck it out, again checking condition in a water bottle.  If it looks clean, add the correct amont and your done.  If not flush again.  You should get 2 flushes and a fil out of a Qt of fluid.  

I use a turkey baster with a hose attached to suck the fluid out of mine.  

An alternate way is to suck the original fluid out.  Fill the trans completely, it should hold most if not all of the qt.  Suck about half the fluid with the hose suck all the way into the trans.  Then using your dipstick mark the hose so it just reaches the full mark on the dipstick.  Suck the rest out using this mark.  When you can suck no more the trans should be at the correct level.  Double check with the dipstick.  I learned this method from Ron Hill I think.  Drain/completely fill the trans during winterizing, drain to correct level in the spring.

[Ken Heyman]

take a look at these discussions from a few weeks ago---

http://c34.org/bbs/index.php?topic=2837.0

http://c34.org/bbs/index.php?topic=2911.0

Ken