Originally Posted by Jay H
Well Gordon, I have to give the guys at the Chrysler dealership credit. While they told me there was no need for an accessory cooler they assured me that if I added an accessory cooler it would not affect my warranty at all, so I was welcome to do it.
I can't really see a downside to installing a high quality accessory cooler that is separate from the engine rad. I'll be stopping in at a couple of local places this week to look into getting one to install. First stop will be my usual garage. The owner has the same model of van and he tows a trailer too, I'll see what he says on the matter.
I hope you have it in writing.. I lost count of the number of times I have received inaccurate verbal information from auto dealers, auto dealer parts managers, and even Toyota tech support.
Many people look at the aux cooler as insurance, and it could very well could be good insurance depending on many variables. If your tug is new and has a 100,000 mile drivetrain warranty (that includes the transmission) and the car maker says it has plenty of cooling as in for towing your trailer, then thats one case where I for one would not worry about it (unless my gauge tells me the temps go up too much).
But if in doubt then, yes, the least risk is from adding the cooler. If it were me, I would still make sure I had a good temp gauge just for the peace of mind and in case there was a problem with the cooling that otherwise might not be detected until too late to avoid damage.
One thing that has not been mentioned is changing the fluid more often. As we know, running the tranny at very high temps for short periods will wear it out fast, and running at higher (but not extreme) temps will wear it out slower, but it all adds up over the miles. When I was towing a pop-up with a Highlander that did NOT have the tow package with aux tranny cooler, I did see a couple of times where the temps got up too 210-215 for short times (hot days in stop-n-go traffic). Although the temps were good almost all the time (max 175-185), I was concerned about the occasional rise and so I replaced the fluid and avoided any damage. This is another reason why I like have the tranny temp gauge, so if I do occasionally run at higher than recommended temp for a short time I will know, and can elect to change the fluid.
BTW, if I were still towing with that Highlander it would
have an auxiliary transmission cooler.