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General => General Discussion => Topic started by: JethroT on October 12, 2011, 08:49:05 AM

Title: Do I need a transmission cooler
Post by: JethroT on October 12, 2011, 08:49:05 AM
Hi guys,

I've been towing a 1400Kg Goldstream with a 2003 Prado 3Ltd diesel for the last 12 months without any obvious concerns, however with a view to longevity I wonder whether I need a transmission cooler coming into the warmer months.

Does anyone have any experience good or bad with transmission coolers.
Title: Re: Do I need a transmission cooler
Post by: TheOtherLeft on October 12, 2011, 08:58:07 AM
Do you have an auto or manual transmission?

Does your transmission fluid look or smell burnt? Unburnt fluid is red in colour, burnt or even old is blackish. Plus burnt fluid smells very different to unburnt fluid.

Even if not a cooler is a very good idea if towing a lot.

It also matters where you mount the cooler. I was told by Natrad that mounting a cooler high up in front of the radiator could be detrimental to the engine as the radiator can't cool properly due to the now hotter air (from the cooler) going to the hot part (top section) of the radiator. You could mount the cooler down lower but then you may have clearance problems if you go through mud/sand.
Title: Re: Do I need a transmission cooler
Post by: JethroT on October 12, 2011, 09:02:08 AM
Thanks,

It's an auto and I haven't noticed any issues with the fluid when I've checked the levels, however I'll go and give it a better inspection now.

Regards
Title: Re: Do I need a transmission cooler
Post by: Bird on October 12, 2011, 09:02:34 AM
If your running an auto, it is a great idea, and will only do you good provided you buy a good one and its protected well.
Title: Re: Do I need a transmission cooler
Post by: Swogjb on October 12, 2011, 09:37:54 AM
I recently had an oil cooler fitted to the Hilux.
Before  I fitted the cooler when towing our Jayco  if I pushed her a bit hard the trans light would come on,  as soon as I backed off the light would go out.
When the trans was getting hot it would change back a gear all the time, almost like the trans didn't know what gear to be in.
I recently tested the cooler out, towing into a strong northerly wind for about 550k upto Mildura.
The transmission worked much better than before, not dropping back a gear all the time and no sign of the trans light.
 :cheers:
Glenn

Title: Re: Do I need a transmission cooler
Post by: sablesoft on October 12, 2011, 10:58:52 AM
I recently had an oil cooler fitted to the Hilux.
Before  I fitted the cooler when towing our Jayco  if I pushed her a bit hard the trans light would come on,  as soon as I backed off the light would go out.
When the trans was getting hot it would change back a gear all the time, almost like the trans didn't know what gear to be in.
I recently tested the cooler out, towing into a strong northerly wind for about 550k upto Mildura.
The transmission worked much better than before, not dropping back a gear all the time and no sign of the trans light.
 :cheers:
Glenn
Hi Glenn,

What Oil Cooler did you use ?

Ray

Title: Re: Do I need a transmission cooler
Post by: gadgetman on October 12, 2011, 11:22:52 AM
I tow a fair bit and haven't had issues with this although if the roads are hilly I tend to keep the gears in 4th - not overdrive, to avoid the gearbox hunting for the right gear.
Rob
Title: Re: Do I need a transmission cooler
Post by: jtraf on October 12, 2011, 12:02:43 PM
I have a GQ Turbo deisel auto and for the sake of peace of mind I fitted a B&M 70297.  It is a largish cooler with built in temp switch that will turn in the built on thermo when oil temp reaches 80deg celcius.

I also have a oil temp guage onto the auto output line and the worst I have seen while towing has been 80deg at the output but it was never hot enough by the time it got to the auto cooler to turn on the thermo so I know that the auto is always cool.

At around the $350 mark it is not cheap but what would an auto failure cost...

HTH

James
Title: Re: Do I need a transmission cooler
Post by: Swogjb on October 12, 2011, 01:02:08 PM
Hi Glenn,

What Oil Cooler did you use ?

Ray




Hi Ray,
My cooler is a Hayden Rapid Cool.
http://www.haydenauto.com/Featured%20Products-Transmission%20and%20Engine%20Oil%20Coolers/Content.aspx
 :cheers:
Title: Re: Do I need a transmission cooler
Post by: Bird on October 12, 2011, 01:40:33 PM
Quote from: jtraf
At around the $350 mark it is not cheap but what would an auto failure cost...
bout 4000.....
Title: Re: Do I need a transmission cooler
Post by: D4D on October 12, 2011, 02:33:55 PM
I plan to do this one day, the problem with the Prado is working out where to fit one as mounting it in front of the radiator is not really possible.

For an authoritative answer try Rodney http://www.automatictransmission.com.au/
Title: Re: Do I need a transmission cooler
Post by: Bird on October 12, 2011, 02:53:11 PM
I found the large PWR ones flow really nicely
Title: Re: Do I need a transmission cooler
Post by: WilSurf on October 12, 2011, 03:10:44 PM
I have added an auto cooler to mine and the temp is definately lower.
The Surf has the transmision fluid running through the radiator to cool down, maybe the Prado has the same.
I have the Craig Davis V8 cooler installed in serie and an additional digital temperature gauge. On our trip towing the KK it showed under 80 degrees while before it was high 90.
Title: Re: Do I need a transmission cooler
Post by: D4D on October 12, 2011, 03:22:12 PM
The Surf has the transmision fluid running through the radiator to cool down, maybe the Prado has the same.

Yes
Title: Re: Do I need a transmission cooler
Post by: Swogjb on October 12, 2011, 03:24:08 PM
Yes

Hilux is the same
Title: Re: Do I need a transmission cooler
Post by: Bird on October 12, 2011, 03:28:14 PM
Quote from: WilSurf
The Surf has the transmision fluid running through the radiator to cool down, maybe the Prado has the same.

it can be a good idea to bypass the radiator... many do this while they are at it, then you dont heat the water and vice versa when you don't need to..

awill4x4 had some top data on this on outers, patrol, and eoz forums..
Title: Re: Do I need a transmission cooler
Post by: WilSurf on October 12, 2011, 03:30:30 PM
Some do by-pass and found that it doesn't work properly.
The transmission fluid is also used to heat up the engine to working temp when the ambient temp is cold.
Title: Re: Do I need a transmission cooler
Post by: dazzler on October 12, 2011, 04:56:37 PM

The Surf has the transmision fluid running through the radiator to cool down, maybe the Prado has the same.


Which is one of the main reasons that the surfs often overheated.  The trans cooler actually blocks the lower radiator outlet on the surf but doesn't on the 4Runner.  You can see the cooler if you pull the radiator.
Title: Re: Do I need a transmission cooler
Post by: dazzler on October 12, 2011, 05:06:49 PM
Hi guys,

I've been towing a 1400Kg Goldstream with a 2003 Prado 3Ltd diesel for the last 12 months without any obvious concerns, however with a view to longevity I wonder whether I need a transmission cooler coming into the warmer months.

Does anyone have any experience good or bad with transmission coolers.

There is an old off road racers saying (probably stolen from someone else) that goes "parts left out cost nothing and create no service problems"

Sure fitting a transmission cooler will cool the trans oil.  But is cool oil what you want?  Its designed to operate at a certain temperature and given the fact that most mechanical wear on components is when cold you may actually be doing more harm than good in the long run.  The trans will take a long time (if ever) to reach the correct operating temperature and would probably only ever get there when you are really flogging it.

The prado has an AT overheat light so I would go off that.  If it comes on then back off.  I am aware the D4D models do this a fair bit when pushing hard in sand but they dont crap themselves.

So my 2c is leave it stock.

cheers
Title: Re: Do I need a transmission cooler
Post by: D4D on October 12, 2011, 05:09:49 PM
The prado has an AT overheat light so I would go off that.  If it comes on then back off.  I am aware the D4D models do this a fair bit when pushing hard in sand but they dont crap themselves.

The 150s are known for this
Title: Re: Do I need a transmission cooler
Post by: Swogjb on October 12, 2011, 06:05:43 PM
I was talking to a transmission specialist and in his opinion all vehicles that are towing on a regular basis should have a cooler fitted.
The difference that it has made to the Hilux in really noticeable.
Before the cooler was fitted you could tell when the oil was starting to get hot before the light would come on. Trans would keep dropping back a gear all the time.
Toyota dealer reckons they fixed the problem by reflashing the computer , but that made bugger all difference.
IMO transmission oil coolers are worth the money.
 :cheers:
Title: Re: Do I need a transmission cooler
Post by: RebsWA on October 12, 2011, 09:28:36 PM
I had an 06 Hilux D4D auto and have towed my Jayco Eagle from Albany WA to Darwin and a few places in between over the last few years. Had some pretty hot weather in all this and had to hot foot it from Kununurra to Perth once for a family emergency. Never had an issue with the auto trans and never seen the temp light on.
Last year I traded it on another new Hilux which I intend to keep longer than the usual 4 years, so I thought I would fit a cooler. After some research I decided to fit an oil thermostat with the cooler so the vehicle operates as Mr Toyota intended, but should the fluid get above the NOT (normal operating temperature) when towing, the fluid is directed thru the cooler. Seemed like reasonable logic to me.
Well after 8,000 kms (but with little towing) I have yet to feel the cooler get hot. It gets tepid as a small volume of fluid is recirculated thru it constantly but it is obvious the thermostat has yet to open.
So that tells a story.
I had also installed a transmission digital temperature gauge prior to fitting the cooler so I could record the before and after effect the cooler had. Needless to say I have noticed no change. One thing I would conclude is that without the thermostat the transmission would probably never get to NOT in cold weather. If that is good or bad I am not sure as I am not a auto trans mechanic but when I first floated the intention to fit a cooler to my Toyota service manager he baulked at the transmission running below NOT.
Anyway that's my 2 bob's worth on the subject and I am satisfied the trans is operating normally but has the provision of an extra cooler should the need arise.
Title: Re: Do I need a transmission cooler
Post by: Black Diamond on October 12, 2011, 09:37:54 PM
Heat is the biggest killer and an aftermarket trans cooler is money well spent in any application especially towing. Don't think DO as a famous coach once said!

:cheers:
Title: Re: Do I need a transmission cooler
Post by: Bird on October 12, 2011, 09:40:47 PM
Quote from: Black Diamond
Heat is the biggest killer and an aftermarket trans cooler is money well spent
x eleventy
Title: Re: Do I need a transmission cooler
Post by: albany_nomads on October 12, 2011, 10:54:48 PM
Which is one of the main reasons that the surfs often overheated.  The trans cooler actually blocks the lower radiator outlet on the surf but doesn't on the 4Runner.  You can see the cooler if you pull the radiator.
Correct on the Surfs,.... the transmission cooler  is a very large tube in the bottom tank of the radiator that also restricts flow of engine coolant..this is great as Will pointed out if you are in JAPAN wheres its cold and the transmission can be used to heat the engine coolant but in Australia you don't want to heat the motor up with the tranny fluid as such the 4 Runners have a more appropriate designed transmission cooler in the Radiator without restricting flow of the engine coolant.
If you are going to bypass the radiator all together and purely depend on a external transmission cooler that's fine but make it large and remember that it needs to be positioned to get air flow when the vehicle isn't moving as well
As such if its not in-line with your engine fan think about an axillary fan..or keep moving  ;D..Whilst I'm a great fan of Autos, and think in some ways make better 4x4's also keep in mind as some one pointed out Temperature is the biggest killers of Auto Trannys..kind regards John
Title: Re: Do I need a transmission cooler
Post by: Signature035 on October 13, 2011, 07:59:46 AM
We also have an 04 TD Prado and have towed a Jayco Outback Eagle for the past 5 years or so......   I was also concerned but opted to monitor the temp to see what was happening.  I (& PradoBB) bought a digital temp monitor.... one of these;

http://www.ebay.com.au/itm/DIGITAL-TEMPERATURE-GAUGE-ENGINE-ALARM-RACING-OVERHEAT-/180696132581?pt=AU_Car_Parts_Accessories&hash=item2a12542be5

and to date I have not seen a temperature recorded that concerned me.....   food for thought?
Title: Re: Do I need a transmission cooler
Post by: D4D on October 13, 2011, 08:00:54 AM
Engine temp or auto temp?
Title: Re: Do I need a transmission cooler
Post by: Bird on October 13, 2011, 08:50:03 AM
Quote from: D4D
Engine temp or auto temp?
I would say engine by the look of it, which is rarely an issue.
Title: Re: Do I need a transmission cooler
Post by: WilSurf on October 13, 2011, 10:03:18 AM
So back to the question: do I need one?

I think the common answer is: you don't NEED it, but it is better to have one.
Title: Re: Do I need a transmission cooler
Post by: Bird on October 13, 2011, 10:18:06 AM
Quote from: WilSurf
So back to the question: do I need one?

I think the common answer is: you don't NEED it, but it is better to have one.

Theres billions of things in the world you dont need, but will make your life easier and safer.
For the small outlay, compared to a box rebuild, I say its a no brainer.

YMMV
Title: Re: Do I need a transmission cooler
Post by: WilSurf on October 13, 2011, 11:11:59 AM
That's what I mean.
Better save then sorry in this case.
Title: Re: Do I need a transmission cooler
Post by: Noelpolar on October 13, 2011, 01:25:52 PM
I have an 04  TD prado as well.....will be towing a Flamingo soon so this was a useful post....thnks for the peace of mind...... Will keep the $ in my pocket.... Maybe just change the fluid a bit more regularly.......Have a taipan exhaust, K&N, DTronic and all going well with 130ks on the clock...... Hopefully will get 400ks out of her!


 
We also have an 04 TD Prado and have towed a Jayco Outback Eagle for the past 5 years or so......   I was also concerned but opted to monitor the temp to see what was happening.  I (& PradoBB) bought a digital temp monitor.... one of these;

http://www.ebay.com.au/itm/DIGITAL-TEMPERATURE-GAUGE-ENGINE-ALARM-RACING-OVERHEAT-/180696132581?pt=AU_Car_Parts_Accessories&hash=item2a12542be5

and to date I have not seen a temperature recorded that concerned me.....   food for thought?
Title: Re: Do I need a transmission cooler
Post by: Matto on October 13, 2011, 02:38:44 PM
So back to the question: do I need one?

I think the common answer is: you don't NEED it, but it is better to have one.
I'd agree with this.

We had the smaller of the two factory-fitted trans coolers on the Pathfinder (why there were two from factory, I'll never know), and never had a problem. Even in soft sand in summer on Moreton Island, or tooling around up here. Never had the trans shut down, or the overheat light come on.

About a year ago we had a big aftermarket cooler fitted in series with the OEM unit. I was getting the gearbox serviced at the time, and figured it was cheap insurance against future gearbox issues since the car now has over 200,000kms on the clock. Quote from the gearbox mech - "You'll never have any gearbox issues with this now". So while I didn't have any problems before, and the 'box is still in great shape, I was happy to spend the extra to not ever worry about it ever again.

Same as anything - vehicles are always made down to a price, to suit the majority of their usage. The majority of 4WDs don't go offroad much, or do much towing. Therefore, there's no incentive for Mr Nissan or Mr Toyota to increase the price of the car for everyone by fitting something that only 10% of their customers will get benefit from. For those of us here who do go offroad and do tow heavy campers, I think it's a good and sensible upgrade.

My $0.0641 (adjusted for the drop in the Aus dollar).

Thanks!
Matto :)
Title: Re: Do I need a transmission cooler
Post by: Signature035 on October 13, 2011, 03:37:54 PM
Engine temp or auto temp?

.....Oooooops.... :-[  now I feel like a goose,  Yes I have it fitted to the engine...... however,   excuse my ignorance, but could this not also be attached to the transmission case to monitor temp changes?
Title: Re: Do I need a transmission cooler
Post by: WilSurf on October 13, 2011, 03:55:30 PM
Different type of gauge as the temperatures are different.
Title: Re: Do I need a transmission cooler
Post by: dazzler on October 13, 2011, 05:12:00 PM
So back to the question: do I need one?

I think the common answer is: you don't NEED it, but it is better to have one.

Your right wil that the majority of the advice is as you say.  

Unfortunately this advice means that your auto trans temp will not reach the correct operating temperature for 99.9% of the time.  You want the oil at operating temperature where it performs as designed.  

The prado is fitted with an overtemp warning light so you can stop before the temp rises too high.  So for that .1% that the trans heats up to a level that toyota deems of concern a light comes on and you can prevent it.

For me thats what I would stick with.

If you want to add one then make sure that it is has a thermostat fitted as per reb's post.  Then you have the best of both worlds.

Does goldstream need one - IMO no.

But hey, we all have em :) , opinions that is :)

cheers
Title: Re: Do I need a transmission cooler
Post by: TheOtherLeft on October 13, 2011, 07:17:59 PM
Different type of gauge as the temperatures are different.

How are the temperatures different? The unit listed earlier uses a sensor bolted to the block as opposed to a traditional temp probe.
Title: Re: Do I need a transmission cooler
Post by: WilSurf on October 13, 2011, 11:01:27 PM
I think that the trans temp is higher then the engine coolant.
Title: Re: Do I need a transmission cooler
Post by: RebsWA on October 13, 2011, 11:33:56 PM
I think that the trans temp is higher then the engine coolant.

I think you will find they are about the same under normal driving.
Title: Re: Do I need a transmission cooler
Post by: RebsWA on October 14, 2011, 01:30:48 AM
How are the temperatures different? The unit listed earlier uses a sensor bolted to the block as opposed to a traditional temp probe.
In my opinion you can use the above mentioned style digital temp gauges with an external sensor (thermistor) bolted to the block or head of the engine, or bolted to some suitable part on the transmission as long as you treat the readings as a guide only as they will be somewhat inaccurate. Essentially they tell you the temperature of the piece of metal they are bolted to and can be a reasonable guide while all systems are functioning normally.

I have experimented with and tested similar units on my last and current D4D and can easily get a 30C-40C difference in engine temp reading just by moving the sensor around on the cylinder head.
Also consider this example, imagine a sensor bolted to some external part of the head or the block and the cold engine you are about to start has lost its coolant overnight thru a split in the bottom radiator hose. Without the coolant to conduct the heat from the internal parts of the engine to the external part where the sensor is located, you will most likely find any damage will be done before you are alerted via the sensor and the gauge. (And your OEM temperature gauge probably wont be of much use in these circumstance either.) None the less it may explain why manufacturers use the coolant temperature for their ECU's as the preferred way to monitor engine temperature.

On the auto trans you would need to mount this type of sensor close to the fluid output line to the cooler as this is where the heated fluid exits the trans and is usually the vicinity where the manufacturers monitor trans fluid temp. It needs to be a good metal to metal contact that is not influenced by exhaust temps or airflow. It is not much use attaching it to the trans sump or thereabouts as "cooled" fluid from the cooler is deposited back in the sump and would influence readings.
Even if fitted as above it would only be a guide as the fluid can heat up quickly under certain circumstances and before the metal body you have the sensor on, registers the change.
While a wonderful bit of kit it is unfortunate I reckon, the manufacturers trans overtemp warning light which is in the fluid and set to trigger at a critical point, it is reactive device that only allows for you to pull up and let the trans cool down.

The best way to monitor trans temperature is with a good quality aftermarket gauge/kit that has the sensor in the output fluid line of the trans.

For the record I have a combined low coolant and temperature alarm on my engine and a separate temp sensor only on my auto trans. I consider the temp sensor on the engine as a cosmetic device of little real value and the one on the trans as a guide that reads approx 10C below the actual trans temp as verified by my dealer on a 40km test run with his laptop plugged into the ECU.
As I have a thermostat controlled aftermarket trans cooler on my vehicle I am not too worried about trans temp but if I had to do it all again I would start with the aftermarket gauge/kit and take it from there.
Apologies for wandering off topic.
Title: Re: Do I need a transmission cooler
Post by: Bird on October 20, 2011, 10:02:20 AM
Have a read of this thread, and take note from post #5 when andrew mentions temps, then down the page..

http://www.patrol4x4.com/forum/nissan-patrol-gu-gr-10/moving-trans-cooler-61150/