At 12:03 PM 2/4/02, John Krawczyk wrote:
>Hi all
>I was checking my fluid level yesterday and found some things odd. Sitting cold in the driveway the level was at the highest mark or slightly higher.

Was this with engine running in Neutral of Park, after putting the lever into Drive and Reverse positions? If not, then the fluid had not been pumped to the cooler, torque converter and the transmission actuators.

>(i have the metal bracket with the notches alongside the res. tube. The photo in the chiltons says this is the max hot mark. I went to the local WAWA for a cup of java and came home and checked again. The level was now at the very bottom notch. (the one way down low on the bracket that doesn't look like it should be a notch). I don't have any noticeable leaks anymore, (beats me why the rear seal doesn't drip anymore) and the transmission shifts fine when hot. Its only seems a little off when driven cold, but it does shift. Sometimes is takes a little more throttle to do so when cold, but when hot i'm ok. I don't have any slipping hot or cold and it pulls thru all the gears like a thoroughbred.
>Is my level correct? I seem to remember when i did a fluid change back in april (only a chiltons and nicols tip site for guidance) that i followed and instruction to fill to the last high mark on the bracket when hot.

>I feel like a moron asking this, because i should know better, But i just cant get it in my mind that that Full hot level is higher than Full cold. You'd think the when its running it draws fluid in. At least to my mind it does.

From the "928S Automatic Transmission A28 Description of Operation" (I think that the info will also apply to the earlier transmissions): "Engine must be running to check ATF level! Only a rough checking of ATF level is possible on a cold transmission. Level in transparent tank must not drop below the cold mark while engine is running.
ATF level rises as transmission temperature increases.
ATF level should be between the max. and min. marks when car has operating temperature.
There is only very little oil between the min. and max. marks, and in fact approx. 200 ml (0.2 ltr.).
If too much ATF is ever added, even unintentionally, it is absolutely essential that the excessive amount be drained again."

Wally Plumley
928 Specialists


At 01:08 PM 2/4/02, John Eifert wrote:
>What happens if you accidentally added too much and didn't know it. What damage will it cause.

Similar to having too much oil in the engine - the working parts will hang down in the fluid, causing churning, foaming and frothing. The transmission operates on hydraulic pressure applying clutches and brake bands - if there is foam instead of solid fluid, you get low and intermittent hydraulic pressure, which can lead to slippage and thus worn clutches and bands.

Wally Plumley
928 Specialists


On my 87 at least, rotating the engine to the 20: mark puts the torque converter plug in the window. Also here are the torque figures -

Pan gasket bolt torque: 8 Nm = 5.9 ftlb.
Drain plug - pan: 14 Nm = 10.2 ftlb.
Drain plug - converter: 14Nm = 10.2 ftlb.