Trans temp gauge with output for external relay?

[Tapani]

Do you guys know other products with a programmable output for an external relay / warning light?

http://www.marshallinstruments.com/products/5037.cfm

Thanks,

/T

edit: Here's another one: http://www.spa-uk.co.uk/Products/View/67

[NiftySVX]

That is cool! The dakota digital one we were discussing had that capability, not sure if they still do or not. But I like that analog one better than the digital dial. Thinking of using it to run the fan are ya? Or the AT OIL TEMP LIGHT?

[Tapani]

The cooler fan

I agree the analogue one is cooler , but the double digital would allow monitoring true engine coolant temp too - instead the dead zone OE gauge

/T

[Tapani]

Does anyone have transmission temperature gauge readings compared to numbers from the TCU?

I installed the Marshall gauge - very nice and controls the cooler fan too :-)

I drilled and tapped the drain plug ofr the sender - see photo. I know theres a bit mass and hysteresis involved here, but I drilled as large a hole as I safly could so that the sensor would be immersed in fluid even though it is sort of "inside" the plud....

When on the move the gauge reads app 25 F lower than the TCU. Measuring the pan surface temp with an infrader thermometer it is very close to the gauge reading (right after coming to a stop). The transmission case is quite a bit hotter - approximately the same as the TCU reads.

When idlling with heat soaked engine and tranny the gauge reads 10F lower than the TCU. The TCU is 186-188 F very constantly, the gauge 170F - I have the thermostatic bypass valve set at 180 F cooler line temperature.

I insulated the plug/sensor so that airflow would not cool it from the outside - have not taken it out after that.... chose a beer over another drive :-).

If any of you have any numbers it would be very interesting to compare notes :-)

Kind regards,

Tapani

[NiftySVX]

My friend I would assume that you are seeing this disparity due to the fact that the sensor for the TCU is placed in contact with the valve body. One would guess that the metal of the valve body itself would be of a different temp then the fluid in the sump as the ATF can dissipate heat so quickly and the aluminum cannot. That would be my guess.

Also, nice plug design. I did one like that myself

EDIT: Pics of where you put the gauge? Mine is in place of the ash tray.

[Tapani]

Yeah, my thoughts are a long those lines too. The tranny goes in overheat mode at 101C (214F). And this is naturally sensed by the TCU.

I've adjusted the cooler fan to kick in at 190F measured by the external gauge.

Adjustment is very easy, so I will just have to drive more to get a good feel what's going on.

I took out the boost gauge - so now I have the wide-band and the trans fluid gauges where the ashtray used to be .

/T