Aftermarket differential cooler installation

I have compiled aftermarket and custom components to install the differential cooler, while I wait to see what the market will offer for the transmission. Since the differential is less critical and less involved, I figured that I would start with the back end and be able to apply some lessons learned when I get to the transmission cooler. I am wiring the systems so I can turn them on and off from the cockpit, I expect to use them primarily at the track.

I started with a custom radiator from Fluidyne, this was made to my specifications and has about 40% more capacity than the factory cooler.


I am starting with the Mocal 2 GPM pump to see how I like it.


The pump will be controlled by a relay I will mount inside the housing under the spare tire space.


I mounted switches in the cockpit for the 2 pumps, top for the transmission, lower switch for the differential.


Had a local hydraulics service shop make the hoses.


I welded mounting tabs on the radiator hosing.


I made a center support for the radiator, this mounts to the steel flange for the plastic housing.



Mounted the pump under the spare tire compartment. The hoses connect to the fill and drain holes in the differential. An inline filter will be added before the pump inlet.


Here is the system mounted in place


Cost of the system:
Radiator $405
Hoses and connectors $115
Pump $165
Relay and switches $12
Wire $10
Brackets , about 3 hours fabricating.

Nice work!

Excellent to see one more done. With a track pack differential cooler, I saw about 180F at the end of a 30 min HPDE session.



What temps have you seen without the cooler for the differential? (IR measured or thermocouples).

We ran ours on our GT and never saw above 181F. Fan does not come on until 190F. (Temps shot with a gun) We will likely install a real gauge and bring the switch inside the car and/or trigger it with a run source. We finished this an hour before we teched in on Thursday. Non speedway tracks I suspect the fan will run.

We have a track pack cover to install, not a lot of room for hose ends so the Track Pack cover will make level checking much easier. Our system holds about 2.5-2.75Qts.

Everything is in the way including the sway bar when routing lines.

Nice work [MENTION=20343]GT_Dave[/MENTION]! Thanks for posting it! Did you go w the track pack diff cover?

No, I am sticking with the original 2 hole cover. If there is a reason in the future that requires the upgrade cover, then I will install it. I don't see any reason that the current setup will give me any problems with track activity. I would be more concerned about the transmission than the diff.

Tomster said:

What temps have you seen without the cooler for the differential? (IR measured or thermocouples).

Click to expand...

I have a differential temperature sensor mounted in the factory hole with a Glowshift gauge in the cockpit. The highest I have seen the differential get in hot weather is about 210F. I am looking to keep that under 180 under any circumstances.

Optimum Performance said:

We ran ours on our GT and never saw above 181F. Fan does not come on until 190F. (Temps shot with a gun) We will likely install a real gauge and bring the switch inside the car and/or trigger it with a run source. We finished this an hour before we teched in on Thursday. Non speedway tracks I suspect the fan will run.

We have a track pack cover to install, not a lot of room for hose ends so the Track Pack cover will make level checking much easier. Our system holds about 2.5-2.75Qts.

Everything is in the way including the sway bar when routing lines.

Click to expand...

Is this something you sell?

wildcatgoal said:

Is this something you sell?

Click to expand...

Not yet, we are not in a rush to market for the sake of being first. Lot's more testing to do and making it no drill is a challenge. We may release the brake cooling kit sooner, we know it works. We also use a 10,000HR $400 pump, Goodridges GMAX hose and fittings with a Setrab fan pack cooler. It will only be for serious people.

GT_Dave said:

I have a differential temperature sensor mounted in the factory hole with a Glowshift gauge in the cockpit. The highest I have seen the differential get in hot weather is about 210F. I am looking to keep that under 180 under any circumstances.

Click to expand...

Hi GT Dave,

Can you post a pic of the Glowshift light in the cockpit? Did you run the sensor from the fill hole?

I know this is a very stupid question since you all are way more smart than me, but for the OEM and aftermarket diff coolers I see they all require a switch, why can’t a thermostatic switch be incorporated? I know there has to be a reason and it’s probably been explained.

Here is how I mounted gauges in the headliner as an upper center console of sorts. At the time, 2 years ago, this was before we knew about the Forscan capabilities. If done today I would most likely do it different and just use the dash display. But it is nice having these gauges as a backup at the track.





The sensor uses the factory sensor port in the stock cover.

Wine dude said:

I know this is a very stupid question since you all are way more smart than me, but for the OEM and aftermarket diff coolers I see they all require a switch, why can’t a thermostatic switch be incorporated? I know there has to be a reason and it’s probably been explained.

Click to expand...

The FP post-market diff cooler kit (M-4000-M8S) has one for 170 degrees. The switch is essentially a manual shutoff/override for the diff cooling system.

Wow, your setup is impressive. I had the idea of installing the AutoMeter Indiglo or something like that. Based on the pic, and the Forscan tweaks, I am now under the assumption that the factory sensors are installed for both differential and tranny? All we need to do is turn on with the Forscan tweak? If so, that’s easier than the OEM kit and the time involved to install it. Thanks

Ok so I am even more stupid than before, why would you need a manual shutoff or override switch, if the pump turns on at 170 and off below 170, why would you turn it off above 170 and let diff get hot?