I installed the Derale in my jeep mainly for the slow trails we are on in East TN and KY. Also for when I am pulling my off road trailer with the roof top tent.
How to install a Derale 20561 transmission cooler on your Wrangler TJ
- Thread starter Jerry Bransford
- Start date
@Jerry Bransford and others, what kind of temps were you seeing after you installed the Derale unit? I'm just curious if anyone has actually monitored before and after temperatures to see what kind of temperature drop difference it makes.
OP
I can't say as I only had a working ATF temperature gauge in my previous TJ with that had a passive extruded aluminum aux cooler. It made a slight improvement in the transmission temperature when making long climbs while towing my trailer. I haven't connected my current TJ's transmission temperature gauge yet. My shoulder had a pretty significant loss in range of motion in recent years which stopped some of my planned work. Fortunately the VA figured out the problem and I'm undergoing weekly physical therapy which is helping significantly. I'm looking forward to more adventures under my TJ starting within the next couple months, starting with finally installing my Savvy tcase shifter and installing the temp sender somewhere in my transmissoin's cooling system. Not sure if I'll go with a pan-mounted or line mounted sensor again, both of which I had in my previous TJ so I could see the temps via a SPDT switch before & after the aux cooler. I'll go with just one this time... likely just monitoring the temps leaving the transmission this time. I may buy another pan and have @mrblaine braze the temperature bung into it for me. I welded the bung into my previous TJ's pan without problem but I blew holes in the new pan I bought for my 42RLE while trying to weld it in. Talk about losing confidence in my welding!
I think with my new Derale cooler (gets here tomorrow), I will install a transmission temperature gauge, probably by way of a bung I'll have welded into the transmission pan. I'd be very curious to see how much the Derale cooler drops the transmission temps. Of course I'd have to monitor temps with and without the cooler I suppose in order to get a good before and after idea.
OP
That was my thought as well. Should be pretty easy to weld a bung in the pan for a sensor.
OP
Fursphere
New Member
I just installed one of these on my '04 LJ this last weekend. Haven't got the fan hooked up yet, but all the plumbing is done. I seem to have a tiny (like, single drop) leak at the fitting going into the cooler's thermostat housing. I've tried loosening it and re-tightening it, but after it cools down after a drive I get a single drop or two on the bottom of that fitting.
Can I put teflon tape or something on those threads? I'm not sure how to solve this issue.
thanks
Can I put teflon tape or something on those threads? I'm not sure how to solve this issue.
thanks
Try some Teflon tape, that’s what I would do!
PuckTruck
New Member
I am installing now, and I too have no label that indicates the positive wire. I wrote to Derale support and this was their response:
In automotive wiring, black is almost always the ground for future reference.
That makes the blue wire the positive wire.
So to make sure, what direction should the fan blow? Should it blow onto the cooler, or suck air through the cooler? It seems both ways would be effective.
PuckTruck
New Member
I reached out again the Derale support and this was their response:
Interesting, we will need to get onto making a correction with that.
It will be pulling the air through the cooler and out the back of the fan when wired properly.
That fan is reversible and can be used either way but pulling is slightly more effective.
I confirmed that this was in fact the way the fan operates, at least with mine. I hope this helps clear this up for others.
BTW: This cooler seems to be very well made.
PuckTruck
New Member
To be clear. To operate like the above example with air being pulled thru the cooler, Black is grounded.
I will need to change mine then. Thank you for the update!
Generally speaking, one wires a fan installed behind the cooler as a puller and a fan in front of the cooler as a pusher. In most cases reversing the direction of air flow is done by reversing the positive and negative wires but some fans have directional blades that must be reversed..
"Puller" fans are almost always more efficient than pushers.
"Puller" fans are almost always more efficient than pushers.
Fursphere
New Member
One more question if I may. I got the minor leak sorted out, but I'm having a difficult time finding switched power to tap into. I'm just not that familiar with the TJ wiring harness. I don't like how its a (claimed) 5-6 amp fan, and they give you a 20 amp fuse to wire in either, so I'll be adding a relay. But I still need something to switch it off of.
Any ideas?
Edit by Jerry Bransford. Connect the fan to unswitched power since it may still benefit by running a bit after the ignition switch is shut off. The fan will shut off automatically once its thermostat is happy with the temperature. Mine often still runs a bit longer after turning the ignition switch off.
Any ideas?
Edit by Jerry Bransford. Connect the fan to unswitched power since it may still benefit by running a bit after the ignition switch is shut off. The fan will shut off automatically once its thermostat is happy with the temperature. Mine often still runs a bit longer after turning the ignition switch off.
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To power the fan pull the cover from the power distribution box (next to the battery) and use a "add-a-circuit" fuse tap for a circuit you know is ignition hot such as the blower motor.
Use a fuse rated for the wire gauge rather than the peak amperage of the Derale fan. (One normally sizes the fuse for the wire gauge and sizes the wire based upon the length of the wire run and peak load of the appliance.) A 20 amp fuse is correct for 12 ga wire; a 15 amp fuse is correct for 14 ga. However, if you are using a relay (not really needed for this application) you could use smaller gauge and a lower amp fuse for the trigger wire and 12 gauge wire with 20 amp fuse near the power source for the power wire.
Use a fuse rated for the wire gauge rather than the peak amperage of the Derale fan. (One normally sizes the fuse for the wire gauge and sizes the wire based upon the length of the wire run and peak load of the appliance.) A 20 amp fuse is correct for 12 ga wire; a 15 amp fuse is correct for 14 ga. However, if you are using a relay (not really needed for this application) you could use smaller gauge and a lower amp fuse for the trigger wire and 12 gauge wire with 20 amp fuse near the power source for the power wire.
So then the question is how do you know which way the fan needs to be to be pulling as oppose to pushing? I'm assuming you had to give it power to figure that out?
Thanks for the update by the way, I'm getting ready to install mine, so this is very helpful.
Mine just arrived in the mail today. Wow, talk about a nice setup. I am actually looking forward to installing this cooler.
I already figured that I would bench test to check the fan direction after reading through the thread. Just to be sure....
I already figured that I would bench test to check the fan direction after reading through the thread. Just to be sure....
I'm going to have to bench test it as well. I want to make sure it's pulling, not pushing.
Thanks Jerry for the install guide, just finished mine today. Black wire is ground to produce a "puller".
The job took quite a while to finish, but it's solid and no leaks. The cooler return line is just barely long enough, and on my '04 the feed line was about 1.5" too long. Likely perfect for those earlier year configs that need to connect to the passenger side of the radiator.
One other note - the trans pumps ATF out damn fast. I decided to change fluid after the original over-heat event that prompted the cooler install, read all the threads on the subject, got 4 qts of ATF+4 opened and ready to pour in as my gallon catch jug filled up, and turned it on. As I ran around to start the first pour, I noticed a good amount already in the jug. By the time (no more than a minute) I poured the first quart in, I had a red puddle on the floor. So plan for a quick evacuation, or maybe a helper to turn off the engine every quart or so allowing the new ATF to get in.
The job took quite a while to finish, but it's solid and no leaks. The cooler return line is just barely long enough, and on my '04 the feed line was about 1.5" too long. Likely perfect for those earlier year configs that need to connect to the passenger side of the radiator.
One other note - the trans pumps ATF out damn fast. I decided to change fluid after the original over-heat event that prompted the cooler install, read all the threads on the subject, got 4 qts of ATF+4 opened and ready to pour in as my gallon catch jug filled up, and turned it on. As I ran around to start the first pour, I noticed a good amount already in the jug. By the time (no more than a minute) I poured the first quart in, I had a red puddle on the floor. So plan for a quick evacuation, or maybe a helper to turn off the engine every quart or so allowing the new ATF to get in.