Transaxle oil cooler pumps Options

[pcar916]

How many of you are using gear pumps instead of diaphragm types and what filter element (micron) sizes are you using?

[J P Stein]

I'm with Chris on this.

Porsche's syncro system of brake bands would seem particularly sensitive to the lube thinning out. The brake band/slider is basically metal to metal less the oil film.
I've seen several brake bands worn flat on the outside.....slider & dog teeth don't live long under these circumstances. Normal wear becomes catastrophic. There would seem to be an ideal temperature range for these bits to work against each other. I also think that heat expansion has little effect on shifting, but gear to gear may be another story......then the different rates of expansion between the Mag case & the steel gears/shafts may well come into play. Of course, when the oil thins, the gears come closer together (less oil film) generating more heat, then I can see the thing cascade on you. Get the sumbitch hot enough and you have no film.......the ring & pinion begin shedding metal and loose their finish surface....more heat....well, you get the idea....

I've torn down a couple trans that had reached the metal shedding point on the R & P......into the recycle bin with those. The pinion shafts were heat discolored about 1/4 of the way up the shaft. (IMG:style_emoticons/default/blink.gif) Since those trans were from low powered cars, I think they were run out of lube.....thus the neglect.