Hayden Automotive 678 Universal Rapid-Cool 9.5” x 11” Add-On Transmission Cooler – Not for Direct Replacement of the OE Cooler

First of all, the quality of the radiator itself is very very solid and well made. The heat sink fins are not too thin like many other aftermarket coolers. It’s very well made, and I’ve always had great luck with Hayden products, like their fan clutches, and transmission fittings. I originally bought a Chinese knockoff 40k trucool transmission cooler and I had to return it even before I even put it in my truck because of how poor the thickness of the radiator fins were. I could literally bend them with my finger nails. Did not feel comfortable about putting it in my truck. It was a massive leak waiting to happen. So I bought this Hayden cooler. It was actually cheaper than the 40k knockoff, and it’s much stronger and better built. I will be installing this tomorrow. EDIT: I installed these 2 days ago. Install was very easy, it look me about 3-4 hours because of all the custom mounting brackets I made, and all the hose routing with protective looms on it. But install was very easy and straightforward. I’ve been driving for the past two days with my scan tool hooked up to monitor the transmission temp, and I’m very happy to see that my transmission temperature does not go above 165F, even in slow stop and go traffic. Before I installed the cooler, my transmission temperature temp used to be around 190F-200F, but I’m glad to see how much cooler it is after the install. Very happy with the results, and this modification will definitely make my transmission last much longer.

After Rebuilding my BAYA V6 transmission on my 7th Gen Accord, I needed something to keep the transmission cool since it does not have a transmission fluid cooler. This has kepty transmission happy and was very easy to install. It is an incredible value for the price and looks great once installed. As you can (or can't) see from the photo: the cooler fits perfectly with very little modification and blends in with the radiator. I installed it onto the frame and not the radiator to allow for better airflow. The finished fitment of the cooler was easy and very compatible within the area I installed it. The size is perfect for cooling and quick installation! Highly recommend this cooler setup from Hayden Automotive!

Installed on a 98 Jeep Cherokee and it works great! The cooler does an amazing job at cooling the transmission and was well worth the time and money to install. It fits perfectly behind the grill and the hose is a match to the factory line size. The included zip ties have held up and you can barley tell they are there and it all fits cleanly behind the grille.

I have a 2007 GMC Yukon 5.3L SLT RWD. This transmission cooler instantly dropped temps from steady 180-190 w/o towing to 155-165 with 90-degree SoCal heat we had last week. Took less than an hour to get installed and was worth every penny.

OK, so I have a 99 Jeep XJ. I dont trust the zips thru the condenser and radiator. I read too many posts on forums saying they ended up with radiator leaks down the road. and some with no more AC. I bought the Hayden bracket kit. I ended up mounting it on the driver side. flipped around so the brackets are closer to the bumper. There are 2 holes that are just behind the bumper than work for mounting, they're a bit tricky but some stuby wrenches and small socket got it done. I stuck 2 of those foam pads to the cooler to pad between the cooler and condenser. And then used 2 of those zips to go above the radiator to keep tension on, I keep the other 2 extra zips in the glove compartment. It took me forever to find a way to mount this thing without pulling the bumper or header panel. I read some people put it in front of the mechanical fan, but my Jeep has 125k and in the morning or when the engine is cold, the tranny doesnt like shifting until its has warmed up. So I figured in front of the electric fan is good compromise. After I mounted it, the rest of the install took literally less than 10 minutes. Its not the prettiest job, but not having to risk my radiator or remove bumper/header panel, makes it worth it to me. Also, if you want consider painting the bracket and nut and bolt before install. Also, the kit came with 11/32" tubing instead of 3/8th. Maybe that is fine, but I ended up ordering Deraile 3/8" transmission hose from Amazon. As my Jeep uses 3/8, so I see no reason to change it. It was fine and works. You also need 3/8" barb connectors and 6 hose clamps total. also doesnt hurt to have a zip tie to tie the hose along the body where you can. I bought mine from Home Depot, but Amazon and Autozone both have it.

Great item, working good so far. Install on XJ as extra transmission cooler and so far satisfied.

After reviewing many after market transmission coolers, I settled on Hayden and I'm glad I did. The install was simple enough. Drawbacks are the hose it came with (needed to order another) and the aluminum fitting is crap; I ordered a brass type from Hayden. The Install was pretty easy. Make certain you use compressed air to blow out the inside of the cooler. I ran ATF through it as well. I fabricated some simple brackets that I fastened to the radiator frame and then bolted the cooler up to it. Temperature dropped immediately, used to run at 190deg now it runs at about 150deg. Can't even tell it is there bc it is black and blends in with the truck radiator. Would buy again!

Ok. I was not holding out for this product. Thought maybe it was too small to be effective. But wow. I have a 2008 Avalanche, 190,000miles. Towing a 2,500lbs trailer at 85-90f outside temp. This little cooler brought my trans temps down 20-25degrees. Impressive. I do suggest getting the hardware bracket kit. Makes it easier for sure.