Hey everyone. I bought a pocket size IR thermometer at Radioshack yesterday to check stuff on my truck and I decided to use it to find out how my trans is running. I accelerated to about 55mph (in a 55 zone) on my way to my apartment and then pulled into the driveway. Immediately I tested the temp at the trans cooler (usually I just touch it and I haven't been burned...yet) and it was around 155F. I also checked the metal cooler line fitting at the radiator, the hose itself to the trans cooler and even the outside of the pan and it was about the same (+ or - 5 degrees). The engine coolant hoses and the intake were around 195 at idle (as it said on the gauge, so I know it is accurate). Is this good? I know it was alot higher in the mountains because I tested the cooler temp by hand and I almost could not keep my hand on it for more than a second. Is that temp good for going from 30 to 55 fast for about 30 seconds and then stopping?

EDIT: The fluid was changed at 99k and a deep pan was installed at that time. The cooler was installed at 88k and the last fluid change was a flush only 2k before that. Lucas Trans Fix was put in both times (full bottle after the flush and half after the change) for better shifting when cold to compensate for the cooler (It worked).

 

I thought someone said something about a guage last time you posted about the fluid temps. Trans fix is most likely thicker than regular fluid so that is going to create more heat since it will not flow as well.

If you look online I'm sure there is a temp chart for trans fluid. But 155 is getting to the top of where it will start breaking down. The cooler you can keep it the better off you are. That seems pretty high for driving 30 seconds, but if you had it floored the entire time I can see it being possible.

 

The Trans Fix is an additive. Originally, it was 1/11th of the fluid capacity (1 quart bottle in a system meant for 11). Now it is half a quart in a system meant for 13.5 (with the trans cooler and deep pan). I didn't use all TransFix if that is what you mean. The rest of the fluid is MAXLIFE, which is now DEXRON VI spec.

I wouldn't say floored it. I rarely take this past 3k and I don't think it has ever been past 4k. I used maybe 1/3-1/2 throttle to get to 55mph. Really about 1-2".

That wasn't really 30 seconds of driving. I drove it around town on my way to my apartment and my apartment is just out of town on a 55mph road. Once I hit the 55mph zone, I got it up to 55 and then soon I reached my apartment and I checked it.

 

Odds are that you have a fluid temp close to that. I don't think it would be out of question. But your reading can be thrown off due to the angle you are measuring and your distance from the target(closer is more accurate, farther will will be thrown off by surrounding area).
I took a class in Infra-Red Thermography and it's not just cut and dry as far as reading IR temperatures. Different surfaces/colors give off different levels of IR. You could have a polished surface that is 75*F and the reflection from a fire in it. You should be able to read the aproximate temperature of the fire on that surface(not a good idea because it is probably out of the tools range).
The point I'm getting at is that you may be getting a slight IR refletion off the exhaust at the point you measured. Just because it's not reflective does not mean it can't reflect that extra 20-30* off a pipe that could be 300*.

Do some research on it, it's pretty interesting. Just the way color affects things in neat. You'll actually learn why white is 'cooler' than 'black'.

 

I held it about an inch away from where I was measuring it if that helps. The range is -20F to 230F because it is a cheap one and I didn't want to buy a more expensive one. It probably isn't 100% accurate, but probably close enough to tell if I have a problem. If I point it at the muffler, all it says is "Hi" for temperature above the range of the tool. I take it to mean that it is way too hot to touch. LOL

So if it is saying it is higher than it actually is, that could mean that the trans is running cooler than the tool thinks, meaning that it would be better off in the long run.

 

I'm not saying that 155 is not the temp of the fluid, just that when dealing with IR there are variables that can drasticly affect readings. For most applications it is pretty accurate but since the exhaust runs somewhat close to the lines I wanted to point that out just in case the fluid temp is not actually 120 or 130 and you're getting readings of 155.

 

Ok. Thanks for the tip. Something to keep in mind.

Why would they route those lines near the exhaust anyway? Could explain why on the S-10s the transmissions only last 150k (everything is crammed and lines are put in places where they don't belong) and a full size pickup with a 350 it could last over 250k on it? A friend of mine (who is actually the mechanic who I usually bring this truck to when I am home from college) has a full size pickup with a 350 that has over 250k on it.