By request, here's what the FSM has to say about the first gen Tundra trans cooler.
Some of you may be faced with having to replace the OEM unit on an older first-gen truck. Your choices are to buy a new OEM unit (probably a dealer-only item), buy a used OEM unit off
ebay or the junkyard (just make sure to flush it well), or buy an aftermarket unit.
My $.02 is that some of the better aftermarket units will allow you to mount a big cooler without over-cooling the trans. These bypass units will only use one or two rows when the fluid is cool and more rows open up when the fluid starts to heat up. For way less $$$, you get more cooling capacity than the OEM unit. The only downside is that the mounting is not a simple three bolt affair. All that said, mounting an aftermarket universal unit is easily done and not suboptimal relative to the OEM setup (IMO).
Trans Cooler FSM Excerpt
Linear Mode
