Towing Technique - 2015 Colorado Auto

My tranny man urged me to bypass the radiator when fitting the aux cooler in my LC200 because the gearbox has a paper filter that, if the tube inside the radiator cracked etc water will get into transmission fluid and destroy the filter and then the gearbox. And he said it happens all to often. Also, with the aux cooler in the radiator will only heat the oil.

I tow in S5 in my 2009 200 series. At 110 k/ph, S4 would be revving too high. It locks up fine in S5....revs are approx 2100 at 110 k/ph.

Gronk if you pull a caravan at 110 km/h than there is something very wrong in your head.
People like you are the ones that lay upside down on the side of the road.
I only hope that no other people get involved in your stupid actions.

You can't use a 200series towing ability and characteristics with a Colorado 2.8 L 4 cyl. The revs and the gear and the possible speeds are simply not relative to each other.

Conversely if you are driving a rig that cannot sit safely on the road at the speed limit, or worse, you do not have the confidence or ability to do so, I would argue it is very much you who are carrying out the stupid action. I see such people every day forcing their ineptitude onto the rest of us. Worst still are the clowns doing 70 just to save fuel. You assume he is towing some 3.5 t behemoth wobbling death trap that so many insist on towing. I have towed my campers all over the outback and highways at the speed limit, like trucks and all other roadworthy vehicles do. To have some keyboard clown suggest it might be dangerous with no prior knowledge of me would be laughable. I know who id rather share a highway with.

flipje....you would do better to get facts before assuming. Gronk could be towing a 1500kg camper in the NT (WHERE SPEED LIMIT IS 140 ON HWY)...

Best to engage brain before mouth...

But the OP does not have a Lancruiser

I actually tow a hybrid that MAY touch approx 1800kg.....and I'd probably do 120+ if in the NT.

But if I had a Colorado like the OP, I wouldn't tow a 3t van with it, but that's just me, I don't believe in towing near the max limit.

For someone to say another person shouldn't tow at the speed limit is showing they may have a problem with their ability to drive.
If someone feels a combination of vehicle and van are not stable or safe at the speed limit, then they need to fix the problem.....get a bigger tow vehicle or a smaller van....or get off the road.

I end up driving the ranger manually. You’ll feel when each gear no longer pulls and wants an up shift. It is a much more relaxed affair than letting the box do its own thing.

I have the Ultragauge which is a far better visual gauge than the scangauge and it is amazing how hot your transmission gets whilst towing. I also fitted a torque converter lock up kit and my tranny now runs at around 70 instead of 110+..

The temp sender in the auto is only there to detect and inform the ECU what viscosity the fluid is so it can operate correctly. It is ONLY a reading of the auto fluid temp reentering the auto after whatever cooling happened, not the exit temp from the torque converter. Just knowing the temp in the box isn't any indication of the heat value being given to the cooling system. A lockup clutch can stop converter slip but may not be the long term answer for many. Knowing the exit temp, has to be a 3rd party NTC sensor on the exit line and digital readout in cab, for you to really know what temp the auto is producing and what temp you are creating in the fluid. That way you can then drive according to the temp. Scan Gauges and the like don't tell the full story at any time.

At least the Scangauge in my case gives me a real good indication of temperature fluctuations. I have settings on my Scangauge to show temperatures at both the pan and the torque converter. Whether that is as near to good as a "NTC sensor on the exit line", I wouldn't know, but at least in the circumstances I am doing the best I can to look after my transmission. I'd rather have the gauge than not. Hopefully I am not getting too far off topic of the original post !!

RMD...My Pajero gives 2 readings...Pan temp and exit pipe temp. The alarm goes off at 147 degrees. The lock kit that many Pajero owners have fitted have been a huge success with no failures. It was developed and sold by a Pajero enthusiast with a smart technical mind. When using the converter we never see high temps and allows us to drive in full auto a lot more. Definitely a mod that makes for more relaxed driving and increased tranny oil life. It is also worth remembering that once the load has come off the unlocked torque convertor, after climbing a steep hill and descending the other side of the hill, the ATF temperature can continue to rise because the torque convertor is not locked up when there is not accelerator input. When the torque convertor is unlocked and the vehicle is "coasting" the ATF does not circulate through the ATF coolers so the ATF is stationary and sitting in a hot torque convertor. This is done to decrease fuel consumption but at the penalty of overheating the ATF. So the ATF takes a long time to cool down, particularly in very hilly country and especially when towing.

Lockup Mate keeps the torque convertor locked up even when there is no accelerator input, this allows the ATF to circulate through the ATF coolers after the load has been reduced and results in ATF temperatures dropping rapidly. Auto Mate works slightly differently as it unlocks the torque convertor when coasting down hill, however there is a special feature that locks the torque convertor up to provide downhill ATF cooling if the ATF is over 85C.

Even though my 200 series is "only" towing a 1800kg max hybrid van, I have found bugger all difference in towing in S5 or in normal auto.
Unless going downhill, forget 6th gear.....it never gets used. But the auto will lockup in 5th or S5 on a flat road and up slight inclines.
At less than the speed limit...usually 110k/ph.....it may have more problems holding ( locking) in 5th or S5, so 4th or S4 may be better for those who travel at slower speeds..

Gronk, in my 2017 200 LC towing in S4 results in a lower fuel burn than in S5. This is because in S4 the tranny locks up and it revs slower than in S5 at the same speed and load buy up to 2 to 3 Lts/100. You have to see it to believe it, it does not sound right but it is.