Trans temp and diff temp...on same gauge question

Agreed.
Never worried about diff temps.
If I was I wouldn't add a gauge. If it's getting hot, syn and an added capacity finned cover, or find a bigger truck would be my suggestion.

theoldwizard1 wrote:
Anyone concerned about rear axle gear oil temp should swithc to a full synthetic.

Indeed, for not much more money (due to the low quantity involved) synthetic fluid is a good choice for this! The aftermarket cover the OP bought is a nice addition, too.

I put all my gauges and sensors on my truck for a planned trip "out West" when the truck was only a year old, and I wanted to be able to keep an eye on things as we traveled so far from home. The fire trucks I run have lots of gauges and indicators for many different functions, and I have become accustomed to being able to monitor what the trucks are doing. Right or wrong, that trait has bled over into my personal life. I have never seen any indication of a problem via the temp gauges on my personal truck, but being able to periodically check certainly brings me peace of mind and may, some day, alert me of a problem before it becomes a catastrophic failure.

Woodtroll wrote:
Agreed on all counts, no technical argument from me. I would offer that relative repeatable values are close enough to figure out if something is wrong, especially once you have kept an eye on things long enough to know what is normal for your truck.

EXCELLENT POINT !

P.S. Anyone concerned about rear axle gear oil temp should swithc to a full synthetic.

Agreed on all counts, no technical argument from me. I would offer that relative repeatable values are close enough to figure out if something is wrong, especially once you have kept an eye on things long enough to know what is normal for your truck. If your differential normally runs 80 degrees above ambient and is now 150 over, something is going on. It doesn't matter if it is 145 or 151, just that it is abnormally high. Some trucks do not have enough empty dash space to add a lot of independent gauges, and I don't think you need individual gauges for values that don't need constant attention, such as you would on exhaust temps on "tuned" diesels.

To each his own; you have to know what you've got and how to make it work for you.

Woodtroll wrote:
I have one temperature gauge on my truck on a three-way switch that I use to monitor engine oil, transmission, and differential temps. It works just fine - whenever I want to check on the temps I just slide the switch through the three positions. However, my gauges are aftermarket (Autometer), and are electrical gauges (not mechanical) that use a sensor that varies the resistance on the ground wire that goes to the gauge.

All "electrical" thermal gauges use a sensor called thermistor (thermal resistor). These devices are only accurate for a limited temperature range. If you need accurate temps (+/- 1 degree) below freezing and above boiling, you will need 2 different sensor (and probably gauges). Of course companies like Autometer are not likely to publish their accuracy band.

I suspect that a very high temps (above 250F) the accuracy could be +/- 10 degrees F.

I have one temperature gauge on my truck on a three-way switch that I use to monitor engine oil, transmission, and differential temps. It works just fine - whenever I want to check on the temps I just slide the switch through the three positions. However, my gauges are aftermarket (Autometer), and are electrical gauges (not mechanical) that use a sensor that varies the resistance on the ground wire that goes to the gauge. If your transmission temp gauge is a factory gauge, knowing what vehicle you have would help folks make appropriate suggestions.

Good luck!
Regan

Thermocouple wiring is what you are talking about.

I'd look at a second gauge, they might be cheap, then mount in under the dash or to the side of the console.

Bill

Trackrig wrote:
Two items to check.

1. If you stick the probe inside of the differential, is it going to hit the gears?

2. My mind is blank at the moment as to what the "cable" is called between the gauge and the probe - is it long enough to reach back to the differential, probably not.

Bill

(see bolt font in above quote)

Thanks, After checking for gear clearance I'll splice in some wire for now. If this works out alright, think I'll install a toggle switch so I can monitor more closely. I bought one of those fancy alum diff covers about year ago because some paint was peeling off and I do change diff oil about every 15k miles. What got me started on this was after thinking about paint peeling; I wondered if the paint peeling on old cover might be because of heat. If trans probe is to long, Mag cover people probably sell a shorter probe. Just wasn't sure about wiring.

Thanks

Two items to check.

1. If you stick the probe inside of the differential, is it going to hit the gears?

2. My mind is blank at the moment as to what the "cable" is called between the gauge and the probe - is it long enough to reach back to the differential, probably not.

Bill