As the topic says i was wondering how to put a transmission temp gauge on a sm465? Has anyone done this?
:)

Temps aren't any issue on manual trans. Not sure why you'd want/need one. :confused:

Thats another ? do i really need one? Itll be used for towing also

You could drill & tap the p.t.o. cover. I saw it mentioned somewhere.
Really should not be an issue, unless you just want to know.
( could be a "peace of mind" kind of thing )

I'd just make just it's full of fluid....you should be fine.

Heat is an issue on auto trans for the reason that clutch facings get destroyed, the trans fluid breaks down and eventually, the trans will die.

Considering that a manual trans has all mechanical heat treated steel internals, nothing short of a nuclear meltdown or an ungodly torque monster motor is going to kill it.

Having said all that, if you did install a temp gauge (which would be as easy as drilling a hole down in the bottom of the case where the oil is, tapping it to the size of the temp probe and running a wire to your gauge), did you think about what you are going to do if you trans gets too hot? Do you even know what too hot for a manual is? I don't.

I think it would be an excercise in futility.;)

I'd be interested in this too. If temps aren't an issue why did dodge add a trans fluid cooler to the 5600 gear box when they mated the unit to their 5.9 HO cummins?

I'm no manual transmission wizard so that's why I ask. :confused:

i'd like to know if it's even possible to kill an sm465 with heat. i think if there's gear oil in it, it lasts forever, right?:laughing:
and yes, temp gauges are for autos.

My 4 speeds have gotten hot enough to physically burn me. Still cooking 2-3 hours after parked. At the temps it was reaching, I'd guess 250-300*. That hot will cook the bearings out of it in a hurry, and break down the oil which wears out the synchros.

That being said, There has been a ton of discussion in general about this in regards to Atlas t-cases reaching 300* ++ in the desert sections of KOH, or V2R. There is an oil pump designed for rear diff coolers(Just saw another link the other day) which can be plumed out of the PTO covers, and would be best running into a new hole somwhere uptop to circulate. A guage would be just as easy, all depends on how hard you are working it. My situation is differant than yours, but it has crossed my mind several times after I got burnt, no sence in bothering with a guage though, unless you are putting a cooler in too. If you think it will be an issue, put a laser thermometer on it and see how how it is getting.

you can use a mech water temp gauge and sender in 1 of the fill/drain holes or weld a bung to a pto cover.

you could even use a elec setup if you knew that the oh,s for the sender matched the gauge.

As a general rule, 250°F is the hottest any manual trans or diff fluid should be allowed to get. Hotter than that and the seals start to deteriorate. Also, regular petroleum gear oils start to break down much above that temp. Finally, temps at the gear interfaces can be 100 or more degrees higher than the bulk oil temp, which breaks down non-synthetics even faster, and if hot enough will start to temper the case on the gears, reducing their hardness.

Normally, heat isn't a problem on a 4 speed or any other manual trans with a direct 1:1 final drive. Heat is generated when the power is actually going through the gears. Overdrive in an OD trans is the biggest heat generator - something like 2-3% of the power transmitted through the gears is turned into heat (this goes for OD in automatics as well). In direct drive, such as 4th in a 4 speed, the gears are spinning but no power is being transmitted through them, so they only make a small amount of heat from simple viscous friction. If you are pulling a long hill in a lower gear, THEN it will make heat.

I have never seen a non-OD transmission that had a proper lube level die from excessive heat. OD transmissions are notorious for running hot, especially while towing, which is why the ZF S6-650 in the newer Fords has an internal pump and a trans lube cooler. GM's version of the same trans doesn't, and they have been known to die from heat-related failures...