Toyota RAV4 Forums banner
1 - 13 of 13 Posts

·
Registered
Joined
·
12 Posts
Discussion Starter · #1 ·
We have owned our Rav for 3 years now and are very happy with it , except for the crazy door lock system which seems to have a mind of it's own, but that is a very minor nit to pick with 57,000 trouble free miles. Question is what exactly does the trailer package include . I know it doesn't include the hitch, the trailer wiring ( not even a play and plug hook up ) so what is included ? I suppose a heavy duty alternator and maybe a heavy duty radiator and a transmission cooler. The reason for the question is I tow a lightweight fiberglass camping trailer, 2400 lbs on a certified scale, and am thinking of adding a transmission cooler if transmission fluid cooling hasn't already addressed in some form or fashion. Thanks Lee
 

·
Registered
Joined
·
1,477 Posts
You will need an atf cooler for sure, even with the towing package atf cooler, the stock temps without towing anything go over 200f easily,with my atf cooler I see about 160f not towing, and 220f when towing my 2600 lbs travel trailer, I can only imagine how high it went before the cooler.
 

·
Premium Member
Joined
·
2,505 Posts
OctaneYou will need an atf cooler for sure, even with the towing package atf cooler, the stock temps without towing anything go over 200f easily,
Do you think we should use a larger ATF cooler, maybe one with a thermostat?
 

·
Registered
Joined
·
9,071 Posts
I don't think that it's necessary to add an aftermarket trans ATF cooler, unless perhaps towing in Sahara-like conditions. The RAV4 V6 with the towing prep package is designed to tow 3500 lbs. as is. If exceeding the rated limit of 3500 lbs. all bets are off . . . .
 
  • Like
Reactions: DVS

·
Super Moderator
Joined
·
11,245 Posts
It's the torque converter that generates most of the heat, namely when it's unlocked. Manually downshifting to 4th or even 3rd at lower speeds to keep the transmission from hunting gears will lower temps considerably since during shifts is when the TC spends the most time unlocked.
 
  • Like
Reactions: DVS and lee senn

·
Registered
Joined
·
1,660 Posts
I don't think that it's necessary to add an aftermarket trans ATF cooler, unless perhaps towing in Sahara-like conditions. The RAV4 V6 with the towing prep package is designed to tow 3500 lbs. as is. If exceeding the rated limit of 3500 lbs. all bets are off . . . .
Blogson, IMO you nailed it.

This is especially true given that the exact same configuration in other countries, such as Australia, have the V6 with Tow Prep package rated at something like 4600 lbs, IIRC.

.
 

·
Registered
Joined
·
1,477 Posts
Do you think we should use a larger ATF cooler, maybe one with a thermostat?
The better one have a low temperature bypass, on mine I noticed the temp rises almost as quickly has before, it just doesn't go as high
 

·
Registered
Joined
·
1,477 Posts
I don't think that it's necessary to add an aftermarket trans ATF cooler, unless perhaps towing in Sahara-like conditions. The RAV4 V6 with the towing prep package is designed to tow 3500 lbs. as is. If exceeding the rated limit of 3500 lbs. all bets are off . . . .
Check the stock atf temps and you might be suprised. I looked around a lot on ws atf on other forums, on the FJ forums lots of people with stock coolers have transmission failures because of heat. Why take the chance?
 

·
Registered
Joined
·
1,477 Posts
It's the torque converter that generates most of the heat, namely when it's unlocked. Manually downshifting to 4th or even 3rd at lower speeds to keep the transmission from hunting gears will lower temps considerably since during shifts is when the TC spends the most time unlocked.
I always thought the same way, but from what I saw the couple of times I towed the travel trailer, 4th gear actually makes the atf go about 10f more than leaving it in 5th an unlocking the tc (on flat ground)
 

·
Super Moderator
Joined
·
11,245 Posts
I always thought the same way, but from what I saw the couple of times I towed the travel trailer, 4th gear actually makes the atf go about 10f more than leaving it in 5th an unlocking the tc (on flat ground)
With nothing slipping, either bands, clutches or the TC, very little heat will be generated but the engine at higher revs will get hotter so maybe that's the effect you saw in 4th. There's also the delay between the actual heat source and the resulting temperature change in a volume of fluid. Add in the fact that the RAV4 unlocks the converter so much to "make" "1/2 gears" and cause & effect gets even more muddled.

On a vehicle specifically designed for towing such as my F-250s the TC unlocks only long enough to smooth the shifts and then relocks immediately. But it doesn't lock at all until it gets above 40 mph and into OD. When I've monitored fluid temperature while towing it stays much hotter below 40 on back roads than it does at 60 or 70 locked on the interstates.
 
1 - 13 of 13 Posts
Top