I am going to be changing the fluid tomorrow (including the converter, yes I have a drain plug). I have seen many discussions on using Type F in place of Dextron, and some using Type F with a quart of non-detergent 30wt to help with lubrication. Anybody do this, particularly with a "well used" 904 trans? Also, I need to adjust the line pressure on the side of the valve body (NOT the kick down linkage). I know that turning the screw counter-clock wise raises the pressure (according to the shop manual). But, it tells how to do it with the valve body out, not installed. I would like any tips on doing this, as I don't want to drop it (done it before on my late '70 Fury w/727, not fun getting parking rod in when laying on back in gravel). Thanks for any advice.

I run skraight type-F in the Duster, going back to the days when I put 20,000 mi a year on it, and no problems. I wouldn't bother with adding oil, that may do more harm than good.

I keep a cut down allen wrench (I think it's 3/16") to do the adjustment in the car.

D/W

_________________

If it ain't broke, fix it!

I know people who've run Ford fluid (Type F) in their Mopars with no problem. I've also known people who've caused themselves large problems by doing so. Type F is an archaic, early-1970s fluid specification. It gives harder shifts, which is great if you're a drag racer. The latest Mopar fluid (ATF+3 or ATF+4) has much better lubricity, much better thermal and shear stability, much lower pour point, much less tendency to form sludge and gum.

Engine oil has NO PLACE IN YOUR TRANSMISSION.

The only way to adjust the line pressure screw properly is to do it with the VB lowered. Sure you can use a sawed-off 90 degree allen wrench while the VB installed, but theres no room to get your measuring apparatus (tape, ruler) in there to set your adjustments.
You can lower the VB part way without disengaging the park lock rod if you want to gain access, but its more easier to work with the VB completely out.

With the VB out, take your measuring tape or ruler and measure the distance from the inside edge of the spring-loaded adjusting plate (in which the screw rides on), to the VB casting. The default setting is 1 5/16, according to the shop manual. From personal experience, a setting of 1 1/4 improved the shifting quality considerably over the stock setting.

The measurement is just a reference, and I can think of myriad ways to measure it with the valve body "installed". The only "proper" way to measure line pressure would be to hook a pressure gauge to the trans.

D/W

_________________

If it ain't broke, fix it!

To add to my earlier post, its easier to work with all four wheels up in the air. That way if the parking lock rod is being a PITA to slip in the case, you could rotate the driveshaft back and forth until the rod slips in.