I have read that many install trans temp gauges. My Dodge only has an idiot light. Am I wrong to assume that this light will come on in time for me to stop what I'm doing and let the thing cool down before I smoke the thing? Bottom line: is the light sufficient to keep the trans safe?

 

The idiot light must be sufficient since mine has come on a few times and the stock tranny still lasted 212k. Overheated fluid degrades faster and should be replaced sooner. If your light does come on pull over and let it idle in N, there is no fluid circulation in park on a stock tranny.

 

The problem with an idiot light, is you never see the temps start to creep up.
You only know there's a problem when you're deep in it.
If you could pull over imediately when you noticed the light, and idle in netural, you might be ok, but who knows?

 

Having burnt up two autos in the past 1 in a Ford and 1 in a Chebby. The answer is install a gauge. Usually when a light comes on you've already lost a lot of the lubricating qualities of your fluid. After installing a gauge, sometimes on long flat stretches I would tow in OD. If I noticed the temp starting to come up then I would shift down to 3rd. With years of towing, before gauge 2 tranny's, after gauges 0 tranny's, I wouldn't ever two without one on an auto again. Look at the following site too see an example of how the heat affects you.
I hope the link works I've never tryed that before.Get a qauge They're cheap and easy to install. Just my $.03.tranny heat

 

I go with the gauge idea myself. You may get lucky relying on a 5 cent idiot light, but then isn't the comfort of actually knowing worth something?

Heck the idiot light may not even function, but you can tell when the gauge is working all the time. Cheap insurance in my mind.