Autos to warm or not to warm?

[wjw]

Hey all,

Looks like the cruiser needs a new bottom tank, so a Q, there are two trains of thought and I'm wondering which is relevant to NZ, specifically the South Island and short trips

1. Should I leave the auto fluid to go trans -> Ext trans rad -> Engine rad -> trans

2. Or put a manual bottom tank on and go trans -> ext trans rad -> trans

I understand it goes through the engine radiator to warm the fluid up, my question is in NZ conditions does it need that?

[jonossiksilvia]

this, i would also like to know as currently im trans - ext cooler - trans but do have the option on my rad to use it to. just havent tried the current setup for long as waiting for cert plate

[jear bear]

Hi, Manual bottom tank? Sorry just wondering what this is? I run an after market ext cooler in my 80 series and dont use the radiator, I have no issues at all but diddnt realise they used the radiator to warm the fluid?

Learn something new every day, I do a lot of coast trips and lake daniels when it is -5 etc and never had a prob with it tho.

Cheers

[tweake]

i would throw out the tank cooler, fit an external and fit an oil cooler thermostat. that will warm up quicker than stock and get around heating the radiator problem.

[DieselBoy]

Hey, from my personal experience on my 80 series which I did lots of towing with, the factory cooler is vital.

In prep for a big mission, I bypassed it and just ran a big oil cooler in front of the radiator. I then towed my little Zook to rallywoods from Hamilton and the trans temp light came on twice. Never had that issue before, the big aftermarket cooler was suppost to make it better, not worse.

So before the trip back I plummed the factory cooler back in so it went through that first and then through the aftermarket cooler. Never had a problem again, and the weight of the truck I was towing around increased dramatically.

So just like engine oil coolers that are incorporated in the radiator tanks (like on the defender) the trans coolers are also highly efficient at dissipating heat into the coolant. Would love to do the calculation to work out what size oil to air trans cooler you would need to equal the factory oil to water cooler.

So long story short, chuck your aftermarket cooler in after the factory cooler for that extra little bit of cooling.

The cooling system is more than adequate to deal with cooling the trans oil a bit.

I would also suspect that the trans oil is pretty warm before the radiator temp has any effect on it, and the flow to the cooler is probably controlled by a thermostat.

[Ginzu8]

I initially had my truck setup trans out - aftermarket cooler - trans in.

Recently I end up going trans out - aftermarket cooler - factory cooler that is part of the bottom of the radiator - trans in.

My tots is that my aftermarket cooler does the majority of the cooling and the cooler/radiator gives the trans fluid some heat before going back into the transmission.

[wsr4x4]

What Diesel Boy said is bang on I can also back this up with personal exp. also you would be quite suprised how cool your bottom tank is when up in running

[wjw]

Thanks DB... I'll keep it inline then, anyone know which way round the pipes are from the trans?

[jonossiksilvia]

Pretty sure the front line on gearbox is oil out and rear oil in

[badnuz]

I had a manual radiator in my 80, so ran 2 aftermarket coolers, had no overheating trans issue, and i would dare say getting the trans over hot (ie warning light coming on) is way more damaging than it being colder, by nature the fluid will heat up thru general driving anyways.. ( i fitted an aftermarket trans temp guage after rebuilding the auto from it cooking the trans fluid )