Just spoke with Ed (owner) from Crown Valley Transmissions that has a 5





with 40 reviews. Note, that's not 4.5 or 4.7 stars, but a full 5 stars! To say I trust him is an understatement.
He told me that I need to change out all the seals. The seals have sand and grit (not the kind of grit that makes you more manly...) and that it's probably from all the off road trails we've done. I'm having him do all new seals and a trans service, e.g. drop the pan. Total when it's all done will be nearer to $2,000 and a couple days. Unfortunately, parts are not local, otherwise I'd have it next day.
While talking with him, I told him how I'm active on a GX forum and that there's been a lot of discussion about transmissions, temperatures and aftermarket coolers. I mentioned how often we, here on MUD talk about transmission temps over 220° F and how it seems like everyone wants to keep their temps under 200°F with trans coolers and all.
He told me that anything under 300°F is fine, very normal and not to worry about it. If your trans temps start reaching 300°F then start to worry, and pull over. I told him that a bunch of guys on the GX forum have added aftermarket transmission coolers and his reply was, it messes with the factory cooling system and doesn't really help.
He also said my GX already has additional cooling that's available for the GX's. Not sure if that's because I have a premium or not, but my guess would be that it is and that mine came with a receiver hitch.
Keep ya'all posted as I find out more.