Diff oil cooler

g59tester · Mar 30, 2023

Can anyone advise me on the availability and rough cost of the oil cooler and brackets for my 250 Turbo.
Eddie

scam75 · Mar 30, 2023

Last I looked the oil cooler loop was available and about £1k from Porsche inc. vat. Didn't price the brackets.

After I broke a 3rd cooler pipe, and trashed a gearbox as a result, I opted for a different solution. One, because they always leak, two, because it's poor design IMO, especially on a lowered car like mine, and three, because one gearbox rebuild is more than enough for anyone!!

Anyway, I got a 13 row Mocal rad and mounted it up out the way above the driveshaft, and ran reinforced rubber pipes back and forward. You will need an adapter kit so it fits the gearbox and then a couple of elbows and stuff. It's a much better solution, and I now have 3 litres oil capacity rather than the stock 2 litres. 3 years on it hasn't lost a drop of oil. All in all cost about £200 for parts. the gearbox rebuild was considerably more................

The likes of Augment Automotive do an off the shelf kit for the conversion.

I found the reason the stock cooler almost always leaks is due to the weight and flexing it does, this problem goes away with rubber piping.

Stuart

TTM · Mar 30, 2023

Interested to see pictures of your cooler, Stuart.
My 968 gearbox has no internal pump, but perhaps would be interesting to improve cooling at some point just to preserve it.

scam75 · Mar 30, 2023

Hi Thom

I don't have any pictures to hand, I will get some next time it's on a ramp. My mate has pictures from when we done it in his garage, might be on his FB page. I will check.

Yes, the extra gearbox oil capacity is a nice by-product of this conversion. Must be running super cool now.

Cheers

Stuart

DavidL · Mar 31, 2023

I've got one of the Augment oil coolers on mine. Same issue as you really, old one died and replacwements were equally as old and likely to fail the moment you put them on and new ones either NLA or a crazy price.
Augment is a completely different design, small ali box akin to a radiator not the long windy thing.Anyway it went on at a service and as far as I know there haven't been any issues.

blade7 · Mar 31, 2023

I wonder how much pressure the gearbox oil pump generates. Pumping oil through a metal tube attached to the gearbox, probably takes less pressure than through longer hoses to a radiator mounted higher.

944Turbo · Mar 31, 2023

On my coupe I had a repair done to the factory cooler by JMG - they replaced the ends with new machined ones bonded in place, It wasn't massively expensive,
Tony

dlknight · Mar 31, 2023

944Turbo said:
On my coupe I had a repair done to the factory cooler by JMG - they replaced the ends with new machined ones bonded in place, It wasn't massively expensive,
Tony

Had the local machine shop make a new end for mine as it had become damaged and started leaking at the oil pump end. I've attached it using some 2-part epoxy but haven't used it yet. I also spent a very long time cleaning and straightening all the cooling fins before a coat of black trim paint to finish it off.

I did have the dimensions somewhere, will have to have a look and will add them to this post if I find them.

The old end is quite easy to remove, gently heat up the end (probably best with an electric heat gun) and keep trying to twist it off, eventually it will just twist right off when the old glue / sealer melts.

scam75 · Mar 31, 2023

blade7 said:
I wonder how much pressure the gearbox oil pump generates. Pumping oil through a metal tube attached to the gearbox, probably takes less pressure than through longer hoses to a radiator mounted higher.

We had the same thoughts when we done mine. It turns out the pump is very effective, although I can't quantify it in pressure. I had hoped it would be and my mate doubted it would be (silly him), but it filled up the new rad in no time with good flow, so it's more than adequate to run a standalone rad set-up. And that is with thick Swepco oil.

If you were to uncurl the 3 loops in the OEM pipe, it probably goes farther than you think! Granted my rad is mounted up out the way so there is that, but as I said, the pump is plenty effective for this mod.

Stuart

blade7 · Mar 31, 2023

Years ago, I worked for a global hydraulics company that designed and made thousands of cooler loops for power steering racks. Quite rightly they were paranoid about failure of the cooling/rack. While it was a simpler design than a 944 gearbox cooler loop, it probably doesn't take much pressure to circulate fluid through either of them. I'd be interested to seen how/where you have mounted the rad on your setup Stuart.

scam75 · Mar 31, 2023

blade7 said:
Years ago, I worked for a global hydraulics company that designed and made thousands of cooler loops for power steering racks. Quite rightly they were paranoid about failure of the cooling/rack. While it was a simpler design than a 944 gearbox cooler loop, it probably doesn't take much pressure to circulate fluid through either of them. I'd be interested to seen how/where you have mounted the rad on your setup Stuart.

Will get some pics when it's next on a ramp. It's up above the OS driveshaft somewhere, angled to get a bit of air flow. Memory fails me other than that, I've built an engine since then!

Stuart

g59tester · Apr 1, 2023

As it happens I picked up my car from Augment yesterday. I was having some corrective body work done and some work on the drivers door handle mechanism which was difficult to operate. I was able to ask Tom about his cooler and he showed me one from his stock. The cooler looked well made and was about 6 /7 inches square. My reversing light switch is u/s and its difficult to access without disturbing the cooler and taking off a drive shaft. With an LSD gearbox the last thing you want is a trail of oil from the cooler should it fail. I've found Augment very easy to deal with. They've also fitted a new Bosch Turbo cooler pump and Thermostat as suggested to me on another thread. We used one which can be fitted to a Cayenne.
Eddie