Transmission oil temperature problem.

[wussyPup]

I just recieved the tru-cool max (the same model as you got) and I'm wondering how to install it. The way it's installed now, the parts 32921D and 32922A are removed and replaced with flexible lines that go trough the lousy tube and fin cooler I have now, without going trough the original radiator.

You will want to ensure that crud has not found its way into the radiator cooler before reconnecting it.

Would it be better to run the oil first to the original radiator and then trough the tru cool max or better the other way?

I guess it'd be better to run it trough the original first, but I'm not sure.

Yes, I believe that is the correct order, radiator cooler first, then cold temperature bypass, then aux cooler. Here's a quote from the Tru-Cool FAQ

Where should I install the cooler?
If possible, locate the cooler in an area where it will be exposed to ram air. This helps maximize cooling. Install the cooler in series and downstream of the radiator in-tank oil cooler. This maximizes heat transfer and decreases transmission warm-up times in colder weather. Most OEM installations are plumbed this way.

Should I disconnect the radiator in-tank oil cooler when I install a Tru-Cool cooler?

Wherever possible do not disconnect the in-tank oil cooler. It offers additional cooling and helps preheat the transmission. In colder climates the in-tank oil cooler should never be disconnected from the system.

If I do it this way, I think I just have to order part 32921D from Toyota, then run a flexible line from the connection 90467-16013 (4) to the inlet of the tru-cool max, and then use the existing flexible line that is connected with the present radiator to connect the tru-cool max outlet back to the transmission trough the 32922 line.

Does that sound ok for you?

Seems right to me, but I think you could use any flex line instead of replacing 32921D. Also, you will want to install the cold temperature bypass after the radiator cooler.

G'luck, -Steve

 

[Cañonero]

Hello, everyone.

After all this time, I found time to install the tru-cool max and re-connect the stock radiator.

The improvement has been huge: the maximum temperature I see now is 220ºF driving very fast in a mountain pass. Before the installation, it reached 270ºF in the same situation. The average temperature in slow roads is 180-190ºF, it used to be 230ºF.

By the way, the biggest improvement was after removing the bypass valve, as it never opened.

Thanks a lot everyone for your help and advises. You've been really helpful.


Now that it's solved, do you think I should replace the ATF?. It's only 6 months and 3000 miles old and it's fully synthetic (well, I added 1 liter of DEXRON III mineral, but 90% is fully synthetic), but, after reaching such high temperatures like 270ºF, I think that is maybe damaged.

At least, according to these tables:

I don't know if this applies to the synthetic fluid too, as I think it resists the high temperature better, but I don't know how much better.

I checked the oil and it's clean and red, it smells and looks like new, but I don't know if the varnishes can be noticed only by looking at it.

 

[Tapage]

I never saw more than 220°F after my tranny B&M cooler .. but still think are high .. seen those graphs,wonder if those apply to the A442 tranny ..

 

[Cruiserdrew]

I remember Rodney's advice, that you wanted it running as close to room temperature as possible. I know I wouldn't want to push the temp envelope and I do run a cross flow cooler on mine.

I really like the idea of one of his extreme valve bodies, but will likely do a 5 speed swap instead.

 

[Tools R Us]

... that you wanted it running as close to room temperature as possible. ...

This is incorrect. If I remember the component wear chart correctly the wear numbers are higher at 120F than 240F. Like most oil lubricated units they have a sweet spot where they run the best, most units about 180F is where they run the best and most reliably.

 

[Cañonero]

Do you think in my case is sensible to replace the oil now?

 

[RedTacoma]

Do you think in my case is sensible to replace the oil now?

Depends what fluid you have, what you had before and how you changed the fluid.
If fluid smells like new then you can keep until 10K then change it. No need to spend extra money. Especially if you had put Mobil ATF or Amsoil ATF. It takes pretty good abuse to burn those two.

 

[Cañonero]

Depends what fluid you have, what you had before and how you changed the fluid.
If fluid smells like new then you can keep until 10K then change it. No need to spend extra money. Especially if you had put Mobil ATF or Amsoil ATF. It takes pretty good abuse to burn those two.

Well, the transmissions was completely rebuilt about 2 years ago. They put in 14 liters of Dexron III mineral ATF and I got it changed after 10000 miles cause I had the A/T light on and I had the same concerns I have now.

When they took it out, it looked clean and red, but, anyway I think it was a good idea to change it after 10000 miles and 305ºF reached.

This time they used fully synthetic oil (I don't know what brand) and they used a machine that replaces all the oil, not only the 5 or 6 liters that you can change opening the screw.

Anyway, if that charts I posted before are right, my fluid must be full of varnishes after reaching 270ºF.

Or maybe that doesn't apply to synthetic oil

 

[Tools R Us]

...
This time they used fully synthetic oil (I don't know what brand) and they used a machine that replaces all the oil, not only the 5 or 6 liters that you can change opening the screw.

Anyway, if that charts I posted before are right, my fluid must be full of varnishes after reaching 270ºF.

Or maybe that doesn't apply to synthetic oil

Synthetic lube is effected less by temp and probably is still good, depending on how long it was driven at high temp. If it was driven at high temp long enough to form significant varnish or carbonize the fluid it will look dark and smell burned. ATF is a good solvent, so if significant varnish were formed, some would be carried in the fluid, turning it tan, brown, black.

If the trans is operating correctly, you have the temps under control and the fluid looks/smells good, I would run it and do drain plug changes at the next few oil changes. Usually the first thing to be damaged in a heat event is the fluid additive package, by changing a portion of the fluid it's replenished. If your really worried, pull a sample and send it to your lab of choice, this will validate your concern or put it to rest.

 

[warpdriv]

Some pix of it in this thread;

https://forum.ih8mud.com/80-series-tech/19299-transmission-fluid-exchange-writeup-2.html

You have a tube style cooler. Although better than nothing, the one Toois R Us posted is more efficient.

 

[Cañonero]

In fact, now I have this tru-cool max that wussy wap reccomended me:

Tru-Cool MAX transmission cooler (Medium Max) Makco Transmission Parts

It performs much better than the tube and fin I had.

 

[mmuthart]

Canonero,

Did you by chance run your new external cooler without yet hooking up the stock in-radiator cooler?

I'm looking for informaion on exactly how effective the stock in-radiator cooler is for cooling transmission fluid.

 

[Cañonero]

I'd say the stock in-radiator cooler is quite efficient.

I didn't run the new tru-cool max without connecting the stock cooler, but I can compare the old tube and fin radiator with the stock, as I firstly removed the tube and fin and reconnected the stock without connecting the tru cool max yet.

I can tell that the difference between the tube and fin radiator and the stock is huge. Much much cooler. Of course, after adding the tru-cool max made a very noticiable improvement as well, but not as much as the stock radiator did.

I'd say it performs very well.

The only concern I got is the chance of it breaking and engine coolant entering the transmission, but that's not very likely to happen I think.

 

[Scalci]

Hi Guys

reading this thread is what happen to me in December 2009, I had to turn back home, and change cars. I have also emailed Rodney in OZ to find out about the VB etc... So this thread helped me quite a lot.

I have an after market OIl Cooler, but a round piped one, Cañonero did you order this cooler? Tru-Cool MAX transmission cooler (Medium Max): transmissioncoolers.us

I am also considering to do the cooler first, check it and then then the VB from Rodney.

What do you guys think?

Scalci

 

[Cañonero]

Yes, that's the one I got and it works really good, it make a big difference.

That should be enough, but considering you are in South Africa, I'd even consider this if you have place in the front: Tru-Cool MAX transmission cooler *No external cold weather thermal bypass: transmissioncoolers.us

I didn't take that cause where I live we have very cold winters and you know an over-cooled transmission is also not good. There is a cold weather bypass, but it doesn't work as good as it should (opens way too late in hot weather in my case).

Anyway, that shouldn't be an issue in your case unless you plan to travel to cold areas, and you could also get a cold weather bypass and connect it only when you travel there.

I think the right order would be:

1-Replace all the fluid in the tranny with a fully synthetic Dexron III or better fluid (I hope you can source those kind of fluids in South Africa easier than in Spain).

2-Get the big cooler.

3-Install the VB kit.

I'd do the first two and then see what happens and think about the VB. The VB will not only help with heat, it will also give you a better shifting, better performance (close to a manual) and even lower consumption in some cases.

 

[Scalci]

Hi, thank you,

While I got my transmission overhauled, I asked them to fit the valve body from AUS as-well. But I still have cooling issues. The previous owner fitted an aftermarket oil cooler, because the LC’s in the UK did not come with an oil cooler, So I stay in South Africa and the temperature is quite hot by nature.


Can someone please post a photo of the original Toyota cooler and where did they mount it?

 

[e9999]

Yes, that's the one I got and it works really good, it make a big difference.

That should be enough, but considering you are in South Africa, I'd even consider this if you have place in the front: Tru-Cool MAX transmission cooler *No external cold weather thermal bypass: transmissioncoolers.us

I didn't take that cause where I live we have very cold winters and you know an over-cooled transmission is also not good. There is a cold weather bypass, but it doesn't work as good as it should (opens way too late in hot weather in my case).

Anyway, that shouldn't be an issue in your case unless you plan to travel to cold areas, and you could also get a cold weather bypass and connect it only when you travel there.

I think the right order would be:

1-Replace all the fluid in the tranny with a fully synthetic Dexron III or better fluid (I hope you can source those kind of fluids in South Africa easier than in Spain).

2-Get the big cooler.

3-Install the VB kit.

I'd do the first two and then see what happens and think about the VB. The VB will not only help with heat, it will also give you a better shifting, better performance (close to a manual) and even lower consumption in some cases.

you know, a piece of cardboard (or -superfancy- plastic) will do wonders to cover the heat exchanger if it gets too cold out there.

 

[e9999]

Hi, thank you,

While I got my transmission overhauled, I asked them to fit the valve body from AUS as-well. But I still have cooling issues. The previous owner fitted an aftermarket oil cooler, because the LC’s in the UK did not come with an oil cooler, So I stay in South Africa and the temperature is quite hot by nature.


Can someone please post a photo of the original Toyota cooler and where did they mount it?

there are pics here for sure, but it's on the right hand side of the main radiator, right in front of it, covering a bit less than half, when you look at the truck from the front. I imagine all world trucks have the correct brackets for plug and play.

 

[Tapage]

Which it's you average outside temp and your average tranny temp . ? coz I saw mine ( when it was ) around 190 - 210 under heavy traffic conditions down here.

 

[S.CarolinaFZJ80]

Have you all ever considered adding a cooling fan in front of the trans oil cooler? Just curious.