There is no max really...
If you have a temp gauge you do not want to see more than 210, after that you severely shorten the fluids life and ability..
You want 175-f to 200-f, at 220-f you took a 80k interval and shortened it to probably around 40k, at 250-f you made it a 20k interval, at 300-f you made it a few thousand, anymore than that and you should have changed it before reading this...
The issues that cause some of these high temps are really common, getting stuck in the snow and continually trying to get out, stuck in mud, stuck in sand, speeds at 85 mph and more without a really good cooler, towing, stop and go traffic in the hot summer air and 4x4 addsa god amount of heat, racing use and finally sitting in park idling waiting for a long time with any variant of the 727 until i think 2005 or 06 when they finally fixed that issue.
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