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gearbox oil cooling

Posted: Tue Dec 07, 2004 5:40 pm
by fuzzysi
hi,

there's been much talk across the various forums of the gearbox oil getting too hot, leading to (amongst other reasons) outboard brake conversions

the SZ has a coolant system for the gearbox oil,

is this a system that can be easily fitted to a gtv/75?

where does the system pick up/dump back the oil?

are these castings/holes present on all transaxles?

is some sort of pump needed to circulate the oil?

the callaway turbo prototype rebuild shows pics of a coolant system being added but no real detail about it.

anyone done it/know how etc......?

simon

Posted: Mon Jan 10, 2005 3:04 am
by Steve R
I've seen this on a racer...

They'd connected fittings to both the drain and refill plugs in the transaxle, ran pipes across to the oposite side of the car (away from hot exhaust), where they went through an oil cooler radiator mounted to catch the underbody air flow. The pipe from the "drain" plug had a small eletric pump fitted, forcing the oil through the radiator, the return of cooled oil squirted back into the "refill" plug on the transaxle. I don't think it was a pressurised system.

Looked pretty straighforward, just a small volume, low pressure pump, some pipes & fittings plus an oil cooler rad with a few brackets.

Posted: Fri Jan 21, 2005 10:52 am
by Barry
Autodelta actually built a mini pump that fitted into the speedo drive and was driven off the mainshaft to pump the oil around-They also had the return above the gear cluster on a spraybar.

Barry

Posted: Sun Jan 23, 2005 6:11 am
by joey
sorry nothing to add but, that transaxle is beautiful !

i actually cried.


how did you clean it like that?

Posted: Sun Jan 23, 2005 8:58 pm
by pancho
Joey,

Either beadblast or chemically strip it - Alkaline based dip or hot water clean. Then paint with VHT or similar spray can.

I am doing this at the moment, the box is being rebuilt, its cleaned already and I will be painting it this weekend, then ready to re-assemble. I also have the oil pump and the fittings for the oil cooler setup. Ready to rock an roll. :)

Posted: Wed Feb 02, 2005 8:04 am
by Jarle
Hei Pancho.
Can you post a pic of your oilcooling system? Is this the same kit that the SZ used or is it made by you? I am also about to mount a cooler for my transaksel.

Jarle

Posted: Thu Feb 03, 2005 3:13 am
by pancho
Hi Jarle,

I am yet to get a pic of it, basically the casing has two AN6 connectors, one on one side and one on the other, the oil goes out the box and gets sucked into the pump, from there it flos into the oil cooler and from ther back to the box, I am goignto hook the pump up to a temp sensor so when it hits a certain temp it turns on and starts the cooling.....then when temps come down it stops.....pics soon.

Posted: Thu Feb 03, 2005 5:15 am
by Micke
What kind of pump are you using Pancho?

Did you measure oil temp without cooling?

I'll probably need cooling too as I make the whole car bottom flat and there will be no air cooling for the box (the brakes yes)

Posted: Thu Feb 03, 2005 6:11 am
by Mats
I got a trans-cooling system from a Nissan s14 lying around the garage, maybe I should start playing around with it.
Hoses, pump and cooler. :)

Posted: Thu Feb 03, 2005 8:05 pm
by pancho
The car isnt even running yet, and probably wont be for about 2 years, considering how long its taking to do things. My 24v 3L engine is still in peices...

The pump to be used will be a selespeed pump. I will be putting a new temp sensor in, then run the switch off that. Temp to turn it on and off may be manual or automated, hopefully automated, hey maybe I can get the Autronic SM2 ECU to turn the pump on and off via one of its inputs ?

Posted: Wed Mar 09, 2005 11:46 pm
by Maurizio
A low budget solution: a fuel pump.
There is someone her in the neighborhood who owned a 2.8 gleich.
On that car the gearbox oil was pumped around by a fuel pump.
The only thing it didn't have was a thermostat to activate the pump.
And I would like to see some sort of a filter in the lines.

Posted: Thu Mar 10, 2005 1:05 am
by Mats
A fuel pump? They flow waaay too much, surely it was restricted somehow?

Posted: Thu Mar 10, 2005 2:38 am
by Maurizio
yes, probably by the viscosity of the oil through a standard fuel pump :lol:
A simple potmeter would be a able to change the flow manually...

Posted: Thu Mar 10, 2005 3:33 am
by Mats
Heh, and something like 10 amps drawn by the pump... No thanks.
Why not just buy a simple displacement pump? There are loads of cars that use them, must be available as OEM parts.