I realize, this is an older thread..
I've got an 06 4Runner, V6 engine with the WS type transmission.
I cannot add fluid to this at home; the process apparently requires the engine be running and warmed up to fill properly, and the fill plug is too close to exhaust / catalytic converter to be comfortable trying to fill while lying on my back underneath it.
I've recently acquired a boat that I will be towing with this. Total load roughly 3800 Lbs, boat and trailer. Call it 4000 with a full fuel load and such for the boat.
Common sense tells me that a tranny cooler would be a good idea.
I ordered a B&M B&M 70264 SuperCooler Automatic Transmission Cooler (14K & change BTU), listed as being suitable for my vehicle. inlet and outlets are both 3/8".
The cooler lines going to the factory cooler in the radiator appear to be significantly larger than 3/8", possibly 1/2". In addition to the inability to add fluid at home to make up for the expanded system capacity & spillage while doing the job, I am concerned with the smaller diameter lines restricting coolant flow.
I consulted the local dealer, to try to verify the real line size on that factory radiator/cooler, and to have them flush/fill (exchange?) the system after the job to get proper fluid level.
The dealer recommended that I not even bother putting the cooler on at all, as it is not needed. His logic is (and it makes sense) that the factory specs for the vehicle specify 5000 Lbs towing capacity as manufactured, and since I'm 20% under that, I shouldn't worry about it, just have the fluid exchanged. (almost 100K miles on the T4R)
In addition, Toyota apparently never offered a factory cooler or option package which included one for this vehicle, which is another indicator that an aftermarket cooler is not needed.
Anyone else's thoughts on this? If I don't have to add a cooler, I'd rather not have to add any more plumbing connections to the system since each one is a potential point of failure, as well as the hoses.
Thanks!