....and a write-up if you're so inclined. Thanks for the useful info.

 

Got the message guys. I'll be snappin and clickin away tonite.

 

I would leave the stock system alone and use an independent sensor for the tranny temp gauge.

 

I installed a B&W or B&M gauge for my a/t as recommended by the manufacture. The gauge was around $50 and installation is a snap. I have rebuilt a lot of a/t's that had temperature gauge senders mounted into the pans. A lot of these had developed leaks in the pan due to cracks or were hit by debris and damaged. Thus, I prefer the oil line installation. I have always monitored my return oil temps and as long as it stays below 220 I have never had a tranny failure. I have used this type of installation for at least 35 years and dozens of installations on everything from race cars, pickups, and Jeeps too. In some cases it takes a long time for the sump temperature to get really hot as to where the return line may show an increase quickly when there is a problem. I used to mount on the inlet side to the cooler but readings were very erratic and I could not make heads or tails as it jumped around to much. Have even used two gauges for the fun of it, one on the inlet and one on the outlet side for test purposes only as I was looking for a blocked cooler. Found there could be 60 degrees variation on the inlet side reading and only 10 degrees after the cooler.

 

Good grief, I think I figured out how to post pics.

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This is the SunPro gage. Notice the 270° sweep. I wanted the gage to have good resolution, look good and be of good quality. This unit was $40 at Pepboys. It was not fun routing the sensor to the transmission mostly because I unnessasarily took the 4x4 shifter knob and transmission shifter off to remove the center console. In the end I had to do neither. I routed the sensor through a grommet for the 4x4 shifter cable. I tapped into a switched 12V for the illumination in the center stack and it lights when switched, however the glow is amber and not green like the rest of the dash. I don't mind.

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The cooler installation was more straightforward.

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This is the easiest part of this install. Just position the cooler in the desired location and push the zip straps though the radiator and condenser and its set. Knowing now that this particular cooler is probably too much cooling I'd have mounted it lower and bought a smaller cooler for less money. Even so, now, I'll never worry about overheating the transmission. Like all installation instructions, it was a bit harder to secure the straps and the radiator shroud had to be loosened to get to the other end of the zips but it was the easiest part and took about 30 mins to get it in place. Once in place, I cut the return line from the cooler.



The yellow lines go to the new supplemental trans cooler. The red line is the uncut transmission discharge line. The Return line is directly behind and I cut it in the middle of the rubber line.


This is the point of no return. The tube from the transmission is mostly aluminum tubing with a short section of rubber to allow for vibration and misalignment. This is where the cut was made. I simply located the return line and cut the rubber section in the middle. I bought 2 brass 3/8 hose to hose barbs from Home Depot and inserted them in either side of the cut hose. Then I attached the supplied hose (from tranny cooler) to both barbs on the cooler (thus making a loop) and then held it up to the two barbs. I then cut the loop where it made sense in relation to the barbs and attached one end of the cut loop to one barb and another to the other barb, thus creating a curcuit leading from the outlet of the stock cooler then out to ther return line, which has been cut, from there to one end of the cooler. The other end of the cooler it then attached to the return line of the transmission. Sorry for the confusion, but in essence, you are splicing the cooler into the return line of the oe cooler.

Finally came the sucky part. Getting the sensor in the pan. Like I said in a previous post. If you install a cooler this size you're transmission temp really doesn't need monitoring. I doubt I'll ever get the setup to break 210°. In any case if you are inclined to install a gage, this is where I ran into pains. I might install the sensor inline if I could get ahold of a inline fitting. I could not so I installed directly into the pan. The first try leaked and I had to remove the pan twice, which is no fun.

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First, the transmission frame must be removed. 3 large bolts and it'll drop out. I took the time to grind away the relief for the front drive shaft which was punched on the wrong side of the frame. You'll see when you take it out. My front drivesahft would crash onto this frame when the suspension was unloaded as when going over jumps or large dips in the road.

Remove the 15 -20 10mm bolts that hold the pan in place. 3 of these are behind the exhaust and will try your patience getting them out. Hopefully you have 1/4" drive universals. I broke a craftsman. Once out,there'll likely be a lake of red oil. Remove the pan and clean. Strip all of the original sealant off. There is no paper or rubber gasket. I used carb cleaner to get it clean. Next drill a hole using a step or unibit to match the the selected fitting provided with your gage. Now here, I ran into problems. I was gonna use the provded pipe fitting and tap the pan, but its hard to find larger pipe taps. If you have them, this'll likely work. If not, like me, I ended up buying a female flare to male tube fitting and an o-ring. For details on this pm me and I'll get the details.

I reinstalled and allowed 18 hours for the sealant bead to cure and filled with new oil. Its been about a month and all is good.

 

Great write up! Thanks for taking the time to do this! I have a stupid question...how do I identify which line is the return vs supply to the tranny? It may be easy, but I have not crawled under there to really inspect.

 

Check this link.

http://www.atsgmiami.com/articles/ht...Supplement.htm

There are two ports on the side of the trans case. One to the cooler and the other the return. The upper is the return. Follow that line to the front and make the cut there. But frankly, I don't think it matters all that much whether you splice into the return or discharge line. As pointed out earlier, the standard transmission cooler is not a typical wound coil in the radiator tank, rather is an integral part of the AC condenser, occupying the lower 1/5 or so of the condenser. I did not notice this until yesterday when someone mentioned it earlier in the thread. I can confirm that when the AC is turned on, the trans temp does increase. This makes sense as the condenser gets hot when the AC is turned on and would affect the integral trans cooler. All the more reason to add a supplemental cooler as we head into the summer months when the AC will be cranking.

 

The AC part of the condenser are separate coils an should have little if any impact to the efficiency of the transmission cooler section. The only thing they share are the adjacent fins and supporting structure. If anything, the temperature should go DOWN as the electric fan comes on low when the AC is on. Are you sure the transmission temp goes up because the AC is on or is there another reason (e.g. AC on AND going up a steep hill )?

 

Might you suggest what cooler you would go with?

 

When the AC turns on, the inside air evaporator gets cold and in turn the AC condenser gets hot, rejecting both the collected heat from the evaporator plus the heat of compression, a thermodynamic term for the power required to turn the compressor. The sum is rejected by the condenser. Before the AC runs, the heat from the transmission is free to flow into the adjacent cool mass of the condenser. When the AC turned on, the heat flow into the cold condenser mass is halted and possibly reversed depending on actual temperature values.

Before I was aware that the condenser was actually 4/5 condenser and 1/5 transmission cooler, I thought it strange that when I turned on the AC, almost immediately the transmission temperature would rise. Now it makes perfect sense especially since I became aware of this on my weekday commute which is 85% freeway and with almost no elavation change.

I am 99.8734224% sure this corrolation exists.