Help Needed Urgently Half Way Through Job

[Smegul]

Hey guys

Im installing a tranny cooler on my r31 turbo.

The cooler has 2 end tanks, with one port on the bottom of the end tank and the other port on the top of the other end tank.

I drew a shiity paint diagram to show you what i mean. Basically does it matter if the trany oil comes in the bottom, or should it go in the top?

Which way does a radiator flow?

Also can anyone tell me which way the oil enters the stock radiator? I.e does it enter in the drivers side of the car, and exit the other side, or the other way around?

http://yfrog.com/mr43785953p

p.s its a series 3 r31, with the re4ro1a tranny, same as r33 gts auto.

[BensDR30]

Fill from the bottom.

Disconnect the lines and crank the car (briefly!) that will reveal which line is which from a flow-perspective.

[Ghostrider]

Your radiator flows in the top and out the bottom, but as for the oil direction I don't know. Having said that you can find out soon enough by running it and see what pipe it comes from and then connect it with the least amount of resistance. Top to bottom again.

[Smegul]

All good found out by cranking. Also found out the car has been running without a thermostat for ....however long.

Now, should I bypass the radiator oil cooler altogether or run the cooler inline with it, if you know what I mean?

[BensDR30]

Hey D,

You've stated some 100% accurate facts about the cooling system - but I would treat the trans cooler differently and here's why:

The engine cooling system (generally) has a bleeding point in the radiator (or nearby)

The engine cooling system is pressurised.

But a trans oil cooler like this has neither of these. So if you fill from the top you may find that air gets trapped in the cooler, reducing the efficiency.

My 2c worth.

Smegul,

You can safely bypass the bottom-tank cooler - but you may find that overdrive lockup does not occur as soon from cold.

[Ghostrider]

Hey Ben,

The radiator information came straight of the R31 manual, but it doesn't say anything about transmission fluid flow. It was a guess on my part as the cooler on my V8 Cressida can flow in either direction.

Just as a point of interest, I don't know of any bleed point in any of the Nissan cooling systems I have dealt with so far. I'm not no anything expert in matters R31, so I normally let these questions slide through to the keeper.

All is cool.

[Factory 5]

I filled my hoses & trans cooler before installation so there was minimal air.

Transmission is staying cooler, but the fluid is grey and silty, plus it wont hold gears when cold. I think its time for a replacement.

The RB30e has a bolt on top of the plenum to purge the air out of the cooling passages (highest point)

especially a problem in the VL commoores as they ar on a slightly different angle to the R31.

the 2x VG30det in the garage have the air outlet, might not be standard though

[BensDR30]

It sounds like the connection orientation isn't a critical factor (FWIW, all the coolers I've mounted have both connections at the top). Andrew - you need a gearbox rebuild, especially if you plan on significantly increasing the torque output of your car.

[Factory 5]

the Z31 in my driveway has a rebuilt 4N71b with $2500 in receipts (apparently) so Im hopeing the L series bellhousing will bolt on and somehow I can use it!

Otherwise a rebuild will be on the cards... quite pricey too by the sound of things.

Same box as the VL commodore so there are shift kits available too.

[Ghostrider]

You're going to have to have or put an L seies front housing on it Mags, the VG front housing is lots diferent.

[Factory 5]

Yeh, makes me wish I kept all those ones I sent to the scrappers.