Write-up for installing 4EAT cooler? (merged thread)

My new Drain Plug

So I go to the Local Auto Part store. (Lordco Auto Parts - Home Page which is suppose to be BC's largest auto parts chain)

Me: "I was wondering if you have a Transmission Drain Plug for a Subaru Forester. It is an M20 x 1.5."
Parts Guy: "What is the make and year?"
Me: "Subaru Forester, an 2007."
Parts Guy after looking on his computer: "The drain plug size isn't in the computer. You'd have to find out the size from the Dealer."
Me: "But I know the size. It is an M20 with a 1.5 mm Thread pitch."
Parts Guy: "That doesn't matter."
Me: "What do you mean that doesn't matter?!?"
Parts Guy: "They don't make Drain Plugs that big. An M20 would be huge."
Me: "...well that is the size it is suppose to be. Could you check to see what you have?"
Parts Guy walks off and comes back a 2 minutes later: "This is the biggest we have."
Me: "This it is. It says right here Subaru Oil/Transmission Drain Plug. It even says M20 x 1.5."
Parts Guy: "Oh."

Anyways, the shop at work did have the 1/8 NPT tap. So I did the drilling and tapping myself. It is ever so slightly off center, but I am not machinist.


I tapped about 1/3, I didn't want to go too deep and over enlarge the Taper of the thread. A good thing because I nearly bottomed out the sender when it came time to cinch it down. I also enlarged 2/3rds of the hole from the other side to give clearance around the sender. The Sender unit is sealed with Teflon Tape. I am not sure how the Teflon stands up to the heat and oil, although I don't think it should matter either way with the NPT thread. The Sender has a grounding wire, so grounding will not be a problem.


Finally I put a few layers of Heat Shrink (increasing in Diameter each time), so give some protection.


So the Drain plug was $6. Drilling and Taping free. I would not recommend trying to tap an NPT if you are not confident about your taping skills. The tapered threads make it more difficult than regular threads.

So I am back from my Trip. I rented a Tent Trailer with a GVWR of 2330 lbs. It weighs 2100lbs (including options) unloaded. When you add my gear, we where probably under 2300 lbs. My Transmission temp sender is in the drain plug.

Without the added cooler, Not towing the Tranny Temp was running (outside Temp 70-75f)
130-138F at speed (45 mph and faster) on the hills.
140-150F in stop and go traffic.
145F Stopped (Idle for 30 minutes) which is what is stated in my manual.

With the added cooler, not towing the Tranny Temp was (outside Temp 70-75F)
110-120F at Speed on the Hills.
135-145F in stop and go traffic.
140F Stopped.

Note that the Cooler is not effective when not moving or moving slowly. I expected this.

With the added cooler, towing the Tent Trailer the Tranny Temp was (outside temp 80F)
115-155F at Speed Through the mountain range.
140-160F in stop and go traffic.
140F Stopped.

At the highest temp the gauge never went over 160F. This was along Highway 4 (Pacific Rim Highway) on Vancouver Highway and it was 27-28C outside (80+F), the temp shot up as we hit the traffic lights in towns we passed through. Although the summit is only a mere 1230 ft, the highway goes up and down a lot (up to 10-12% grade in areas), and is very narrow and winding.

I will try to get pics of the Cooler installed next week.

Here is some pics of my Cooler Install. Basically the same as SuperRu and others. My Cooler it like the 'SuperCooler' one but didn't come with any metal mounting brackets.

I made a three piece mounting system (shown here). One long bar that will go across the top. The smaller bar will mount on the bottom. The 'Z' shaped (offset) bar attaches between the long bar and the rubber mount for the condenser.


This shows the 'Z' piece installed. As I said, I bolted to the rubber mount of the Condenser. It is bent so that it is parallel to the other mounting surface in the center. This is because the Rubber mount sticks out father than the center bar. I attached a long bolts so the threads suck outward. This was to make the next step in the install easier. All the mounting locations I used were pre-existing.


The smaller bar is to go from the bottom of the cooler to the bracket that holds the 'Outside Temp' sensor (I think). I popped off the Temp sensor and put a bolt here like above.


The two bars that attach to the cooler are set up like this.


Here is the top of the installed cool.


This is the bottom. I reattached the Temp sensor to one of the holes in my mounting bar.


So there you have it. The Rest of the install, attaching the pipping, is the same as everyone else. Here is a couple of photos.

Before: This is the view from by the front wheel well. I had to take the small cover (in front of the wheel well) off here to access the OEM hose clamp.


After: This is the new hoses attached. Viewed from under the engine.