Automatic Transmission Cooler

[kiwipete]

I am looking at placing an aftermarket transmission cooler on my Terrano.
Since lifting my truck, I think the existing cooler thats part of the radiator, is now not operating as it should, as the radiator is in a slightly different position. Phew, that was a long sentence.
I have noticed that when hot, the trans oil is comming out the breather.

Can anyone suggest a suitable cooler to look at thats easily available here in NZ?

[Mark]

I am looking at placing an aftermarket transmission cooler on my Terrano.
Since lifting my truck, I think the existing cooler thats part of the radiator, is now not operating as it should, as the radiator is in a slightly different position. Phew, that was a long sentence.
I have noticed that when hot, the trans oil is comming out the breather.

Can anyone suggest a suitable cooler to look at thats easily available here in NZ?

I got mine from BNT. They had a range of sizes and I think I went for the biggest one for the Safari, even though they suggested that a smaller one would do the job. I plumbed it up so that it still ran through the existing radiator one as well. I would say that it's a 50/50 what people recommend on that, but I chose to stick with the option that seemed the safest

[kiwipete]

Cheers Mark, any idea on costs?

[Mark]

I just went back to my thread about it and saw this:

I have found that the best size (that will fit) will be about 255x280x19. That's deemed to be "quite a large" one and the price ranged from $195 - $248.

I'm pretty sure that I got it for $195 or $200.

[kiwipete]

Cheers Mark, thinking of bypassing the origonal one all the same.
Will check out BNT tomorrow.

[wjw]

Cheers Mark, thinking of bypassing the origonal one all the same.
Will check out BNT tomorrow.

Just be careful you don't run the trans too cold as it shortens their life..

[TJ]

Cheers Mark, thinking of bypassing the origonal one all the same.
Will check out BNT tomorrow.

Just be careful you don't run the trans too cold as it shortens their life..

I was told to
- go from tranny to external cooler (with a flow control valve that bypasses the cooler when oil is not hot enough);
- go from external cooler to the radiator cooler (to slightly warm it up); and
- go back to the tranny.

The logic is that you don't want extra cold oil hitting very warm/hot tranny internals as the thermal shock can do damage. This is particularly true for areas where it gets really cold. Also, if you don't bypass the cooler initially when the oil is heating up, it will take a very long time for the tranny to get upto operating temperature (again, bad for internal and condensation in oil not burning off).

[2MEKE]

Just be careful you don't run the trans too cold as it shortens their life..

What is the ideal temp for an auto to be running at?

[kiwipete]

A large AT cooler at BNT, (8cyl, diesel etc, sorta A4 size) was a meagre $115.00 +GST for me, just have to sort out the correct hose dia for it.
Instructions suggest placing it in series, so thats what i'll do.
Seems easy enough to do too.

I just hope there will be enough space between the radiator and the fan blades for it.
Should be though. What flex does one get on the fan blades?

[oldblue]

With the bottom radiater cooler only, the temp of the Auto oil will be the same as the engine water temp, under normal driveing. 180degF 82degC

[DieselBoy]

With the bottom radiater cooler only, the temp of the Auto oil will be the same as the engine water temp, under normal driveing. 180degF 82degC

I have fitted an oil temperature gauge to the oil pan on the tranny in my 80 series. I have also fitted an aftermarket cooler after the factory cooler.

The oil temp around town and on the open road is a stable 60 degrees, that hasn't changed since i fitted the after market cooler after the factory cooler(in the base of the radiator).

Under load such as towing it runs at around the 80 degree mark, the trans temp light flicks on at the 110 degree mark.

On a Terrano, the general rule is to bypass the factory cooler altogether as they are prone to block up with the metal filings etc generated in the trans. The trans is also cleverly set up, in that the trans won't shift into lockup untill it reaches the correct opperating temperature, and we also live in a very temperate climate, so i definatly wouldn't be loosing any sleep over thermal shock and slow warm up

Your primary concern is stopping that oil from getting to hot, as when hot the oil strarts to burn it creates carbon deposits which damages the seals in the trans, leading to a rebuild.

[TJ]

On a Terrano, the general rule is to bypass the factory cooler altogether as they are prone to block up with the metal filings etc generated in the trans.

Do you not have an internal filter (that needs to be replaced at a certain set interval) in your auto tranny? If not, you can install an external filter inline to eliminate the issues noted above.

My transmission has an internal filter on the oil pick-up and it gets replaced when I change the oil (every time).

[DieselBoy]

On most autos, the internal filter is last in line before the oil is returned to the sump, and is there for after the cooler. As a result the cooler can and does become blocked and less effective over time.

[TJ]

On most autos, the internal filter is last in line before the oil is returned to the sump, and is there for after the cooler. As a result the cooler can and does become blocked and less effective over time.

I used to have an external inline filter on the out line of the tranny, may be I should just put it back on. I am confident my internal filter is on the pick-up side, but I'll check again when its due for change.

[kiwipete]

Got a filter with the gasket from Repco, even got some discount with the oil too.

My tranny cooler was $119.00 inc GST so I was pleased with that as it was $170+ trade.

Will be doing it tomorrow if the rain allows. Just have to seperate the AC radiator from the main radiator so i can get the cable tie things through for the AT cooler.
Otherwise it dosent look too hard to install.
I would look at a temp guage for it if they were available in miniature form, ie 25mm dia as I would like a turbo boost one as well as a compressor pressure one. Space is an issue for me you see, I cannot and will not fit std size guages in.

[darinz]

The single biggest killer or Terrano and Safari auto's is the factory cooler that is inside the radiator. Quite simply as the torque convertor linings wear they block the cooler. The oil goes from the cooler to the gear set so once blocked the gearset fails and that is the end of the entire trans!
The SINGLE MOST IMPORTANT THING WITH A NISSAN 4X4 AUTO IS TO BYPASS THE FACTORY COOLER ALTOGETHER.
Sorry for shouting but following that advice will save you money!!!!!!!
Unless you drive in snow then the oil being to cold is highly unlikely in NZ.
The other thing if you want really good trans life is to use synthetic fluid as it handle high temp much better and the Redline fluid I use is garanteed for 160,000k's so it works out much cheaper in the long run.
I have 375hp (280kw) at the wheels and my Safari trans handles it fine, but it has been modified a bit.