Can I run a transmission cooler under normal driving conditions?

[J_D 2.0]

I normally allow my car to idle (warmup) upon a cold start for 2-3 mins for peace of mind and the fact the car is old etc.. would that possibly be enough to warm up the transmission in the process?

Modern cars don’t really need to be warmed up at all (unless it’s snowing outside). Like Immortality said the most important thing is to not flog it until it’s fully warmed up, which takes a good 30 minutes or so for the transmission and engine oil on a cool day.

In winter my engine oil doesn’t even get to its full operational temperature on my 25km drive to work. I’ve heard it said that the biggest killer of valve springs is flogging the car while the engine isn’t up to temperature. The cold valve springs can’t take the flogging and snap.

Many other parts of a car are in the same boat so not getting up it for the rent while it’s still cold is a good way to increase engine and drivetrain longevity.

 

[losh1971]

I've tried to keep my revs at under 1500 like some say you need to when cold and taking off. I've come to the realisation this really isn't possible without a lot of pig. Now I try to stay around 2000 which is ok, just, but hard to shift at those low revs, especially when cold.

 

[Anthony .]

Modern cars don’t really need to be warmed up at all (unless it’s snowing outside). Like Immortality said the most important thing is to not flog it until it’s fully warmed up, which takes a good 30 minutes or so for the transmission and engine oil on a cool day.

In winter my engine oil doesn’t even get to its full operational temperature on my 25km drive to work. I’ve heard it said that the biggest killer of valve springs is flogging the car while the engine isn’t up to temperature. The cold valve springs can’t take the flogging and snap.

Many other parts of a car are in the same boat so not getting up it for the rent while it’s still cold is a good way to increase engine and drivetrain longevity.

Totally agree mate. It is just cruel to flog a cold engine

 

[Anthony .]

I've tried to keep my revs at under 1500 like some say you need to when cold and taking off. I've come to the realisation this really isn't possible without a lot of pig. Now I try to stay around 2000 which is ok, just, but hard to shift at those low revs, especially when cold.

I can’t really go below 2000rpm as the area I live has a few small hills. I thought up to 3k revs is fine when cold though, but opinions differ

 

[Anthony .]

I've always run external coolers on my cars and I've never run them through the radiator, that being said I don't live in a cold climate. I can't speak for areas that get to sub 0 temperatures.

I've always run them direct from the trans to the cooler and bypassed the radiator. I've had to deal with a fleet of BA falcons that milkshaked the transmissions when the radiator split which since has made me not trust radiator coolers (particularly on plastic tanked radiators).

I've had 4l60's run to 500,000km so I'd think if there was a problem doing it this way I'd have noticed it by now. My current one has 300,000km with a 3200RPM stall converter thats under heavy load, still going strong and never exceeds 80c at the track.

I'm about to put one on my VE too which will be a standlone cooler and not in series.

Did you notice the first cold few shifts with the 4l60e become even firmer with the transmission cooler?

 

[Immortality]

First shift will probably always feel a bit harsh, cold fluid is more viscous and it is a hydraulic transmission. Once it warms up a little and the fluid thins out it will feel more normal.

The other thing to remember is that we are talking about older well used 4l60e transmissions, these things wear out, there are leaks everywhere in the system, there are lots of moving parts, alloy on alloy that wear with age. A lot of the upgrade parts exist in part to stop those leaks.

 

[someguy360]

Did you notice the first cold few shifts with the 4l60e become even firmer with the transmission cooler?

You wouldn't notice the difference to be honest.

The radiator of the car is going to be stone cold just like the trans cooler for the first couple of minutes anyway. I think the thing your missing here, when you cold start the car, the trans fluid is going to be cold whether it's run through the radiator or not....it takes a while for coolant temp to rise in the radiator.

Like Immortality said, it's the nature of hydraulic fluid to behave different at different temps, much like engine oil viscosity will change with temps.

 

[Anthony .]

I've always run external coolers on my cars and I've never run them through the radiator, that being said I don't live in a cold climate. I can't speak for areas that get to sub 0 temperatures.

I've always run them direct from the trans to the cooler and bypassed the radiator. I've had to deal with a fleet of BA falcons that milkshaked the transmissions when the radiator split which since has made me not trust radiator coolers (particularly on plastic tanked radiators).

I've had 4l60's run to 500,000km so I'd think if there was a problem doing it this way I'd have noticed it by now. My current one has 300,000km with a 3200RPM stall converter thats under heavy load, still going strong and never exceeds 80c at the track.

I'm about to put one on my VE too which will be a standlone cooler and not in series.

That’s a hell of a lot of mileage! Can I just ask, what was your servicing routine like? We’re you running a standard valve body or a shift kit?
Cheers

 

[someguy360]

That’s a hell of a lot of mileage! Can I just ask, what was your servicing routine like? We’re you running a standard valve body or a shift kit?
Cheers

Serviced every 20-30,000km with fresh fluid an filter.

Generally I've run stock valve bodies with a bit more line pressure in the tune to firm up the shifts (which as a byproduct creates less slip and less heat).

That being said, I drive like an 85 year old on the street. I don't floor the car or accelerate hard, I don't do skids, I don't think I've ever even been wide open throttle or to the redline on the street.

They only get abused at the track which is maybe once or twice a year.

If you service them regularly, keep them cool, and don't drive like a boy racer they'll look after you.

 

[vc commodore]

An older car of mine, when I bought it I had to get the auto serviced as it was low on fluid and wasn't too sure how long it had been run like that....I drove it back 300K like this.

I put a trans cooler on prior to the service, so it went from the trans to the rad to the cooler back to the trans.

Got the gearbox serviced and the person that id it said, if the same gearbox is in it in 12 months, bring it back.....

That was 15 years ago and the same gearbox is still in the car, with the trans cooler fitted.....

Oh and the gearbox is a BW35....For those old enough to remember back to those gearboxes, will know how good they are...