Anthony, tell us about trans temp gauge -

Submitted: Sunday, Jul 11, 2004 at 07:17
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Where can we get them? How much do they cost? Sounds like a great idea, we want one. Thanks, Motherhen.
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Reply By: Deleted User - Sunday, Jul 11, 2004 at 07:19

Sunday, Jul 11, 2004 at 07:19
Motherhen, A good all-round gauge to use is VDO. They make a range called Cockpit Vision that is reasonably priced. They are 50mm gauges and have a range of pods available to mount them in the vehicle. Cost is around $70 ...I think. I use Autometer from the USA only because I've used them since teenage. They are getting very expensive and the cost is not justified for a trans gauge in anything but a racecar now. The main hassle will be fitting of the gauge sender/sensor that reads the temp ...and where to put it... My favoured position is in the transmission pan. This can be done at trans service time as the pan comes off to fit a new filter to the trans. Unfortunately there is no threaded "boss" on the pan just to screw the sensor in so one has to be attached to the pan. Good mechanical practice dictates that this should be made as follows .... A piece of steel bar 25mm in dia. and 10mm thick is drilled and tapped for the sensor to screw into ..usually a 1/8th NPT-27 thread ... check with VDO for sensor thread size. A 14mm (approx) hole is drilled in the pan. I usually make it in the rear vertical face of the pan so it (and wire to it) is protected somewhat from stones and scrapes from off-roading. This "boss" is then TIG welded to the pan over the hole and the sensor screwed in with a bit of sealant. Pan is re-fitted and wire to sensor is attached and then run to gauge. If the pan is coming off anyway a machine shop should be able to make/fit boss to pan for $40-60 ..... If the pan is not coming off for some time in my F250 because filter change is not close yet you may be able to fit sensor in the transmission pressure testing port. The thread in this port is 1/8th NPT-27 in many makes of vehicle including the F250. I used this port to screw in the sensor BUT there is a caveat here ...the sensor must NOT protrude past the thread depth and into the gallery as it might interfere with the oil flow through the gallery. Sensors come in a range of lengths to suit different depths needed. The best way to have the sensor installed in this position is via a trans repair shop. They will be able to check sensor depth against thread depth in the diagnostic port. Shouldnt charge much to unscrew plug and screw in sensor. A good way to check thread depth is a piece of copper wire with a 5mm 90 deg bend on end and poke in port and pull back until wire angle hits bottom of threaded port and then mark wire at top of thread ..pull out and measure ... should be around 1/2 inch or so. The other connections to the gauge (usually) are just a power wire, earth and the same again if you want the gauge lit at night. Below is a pic of the VDO gauge. The range of this gauge is good for auto trans temp ... 40 -120 deg C. Once you have a gauge fitted and see if the trans is getting too hot you can take steps to cool it via trans coolers. Regards Anthony Explore this Great Land ...Do it Easy ...Tow a Bushtracker
AnswerID: 562646

Reply By: Bushtracker42 - Sunday, Jul 11, 2004 at 07:20

Sunday, Jul 11, 2004 at 07:20

Last time you mentioned exhaust temperature gauges, I
went up the street and found VDO did not have the temperature range you were
using. I’ve held back looking for a matching set. Mind you even with a
cruiser, I can’t find the space compared to the old ‘sporty corty’

I just looked at the Autometer. Nice gear, but I can
see what you mean about the $. Mind you, especially with vibration,
nothing like good gear.

As I’m in the industrial instrumentation game, looks
like I will put a multi-display digital system in. It will save the space, accept
as many inputs as I need, and I’m sure I can make it up out of old
demo/unused bits. I have this lovely LCD display that can be backlit with
orange or red – 2 weeks old is old demo stock isn’t it?


Gary Harding

TriSys Engineering/III

AnswerID: 562647

Reply By: Deleted User - Sunday, Jul 11, 2004 at 07:21

Sunday, Jul 11, 2004 at 07:21
Gary, Ah yes ! A guy after my own heart ..... [smile] A digital readout from 4-5 different senders by a press of a button sounds COOL to me !!! Maybe even a "K" type thermocouple on the turbo housing as well as one in the exhaust. The question is ...are you going pre-turbo or post turbo with the thermocouple for the pyro ? VDO do a 50mm pyrometer now .... from 100 to 900 deg C ..has a nut to weld onto exhaust pipe .... that a 1/8NPT screws into ... If you want to go into the exhaust manifold with tap for the EGT sensor .... a couple of tips if not removing the manifold .... use tapping grease not oil on the tap, it will trap more swarf .... if you can have someone hold a vacuum cleaner sucking at the hole while you drill and tap, well and good ..... run a flexible magnet into the hole and go up stream and downstream of the hole to pick up all the swarf/particles from inside. We dont want any of that going near the turbo shaft and bearing on start -up. I must admit I went post turbo with mine but I will shift it to pre-turbo for a more accurate exhaust turbine temp. Its on the list !! [smile] Best placement in the exhaust stream as you probably know is the middle third of the pipe diameter. Regards Anthony Explore this Great Land ...Do it Easy ...Tow a Bushtracker
AnswerID: 562648

Reply By: Bushtracker42 - Sunday, Jul 11, 2004 at 07:22

Sunday, Jul 11, 2004 at 07:22
Thanks for the thoughts in placement. I’ll
worry about the system 1st and then look to where. I don’t have
much time post holidays and now they are only 3 weeks, so we are hoping to get
to copeton on the last 2 days. I will look you up for some advice.

Maybe I should go all hog. I have this nice
temperature pyro colour ‘camera’. $16K worth, but I could hop out
each time I stopped and check for hot spots and store the image.


Gary Harding

TriSys Engineering/III

AnswerID: 562649

Reply By: Deleted User - Sunday, Jul 11, 2004 at 07:23

Sunday, Jul 11, 2004 at 07:23
Gary, You reckon that's a cool machine .... my youngest brother (Mechanical Engineer) has a machine (via his employer) for condition monitoring large bearings in separators etc in Gold mines and the sugar industry. You place the probe near the bearing while it is turning and it gives you a frequency readout that the bearing is transmitting then compare this to the frequency of a new bearing and he can give a lifespan left in the bearing to predetermine downtime to change it. Cost of Condition Monitor $40k ..cost of bearing $30k !!! I've asked him to check my BT wheel bearings annually with it .... all we have to do is figure how to hang off the BT and place probe on stub axle at 100 kph !!! [grin] Anthony Explore this Great Land ...Do it Easy ...Tow a Bushtracker
AnswerID: 562650

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