40k Transmission Oil Cooler lpd47391 with Thermal Bypass Valve 708-4739P6 Compatible with tru Cool Heavy Duty 40,000 GVW Max - Low Pressure Drop Trans Cooler

Works great on my GMC van keeps the transmission cool very easy to install

I replaced the small factory tow package cooler since my temps were near 200 degrees and would go over 200 degrees pulling my boat. I flipped the bottom bracket around and used a grinder to notch it so I could mount the trans cooler to it (had to slide the cooler to the passenger side a bit to clear the mount for the PS cooler). I used a brake line cutter to cut the factory lines off horizontal, and then used a brake flare tool to slightly flare them. I doubled up on the clamps where the hose connected to the factory lines. On the cooler, I used pipe thread tape around the fittings to ensure no leaks. Pros: seems to be working good. Put about 50 miles on the truck last night on the highway going 80 MPH with the AC running. Temps never got above the halfway mark from 100 to 200 (so I'm guessing that's 150 or 160 degrees). Install took me about 2 hours in my driveway. I used everything included in the kit (had to cut the hose to fit). Cons: fins are really easy to bend. I had to use a small flat blade screwdriver to straighten some of them out after I was done mounting the cooler. Also, the included clamps are cheap. I've got a tiny drip from the return hose where it clamps to the cooler fitting. I'm going to replace that clamp with a clamp from the auto parts store tonight. My advice would be just get 2 packs of small hose clamps from your local auto parts store and use those instead of the included ones. Also that included screws will strip easily at the phillips head. I used a 10mm socket to tighten them. I snapped one off but I guess I didn't drill a large enough pilot hole for it to mount to the bracket on my 2000 Chevy Silverado Z71. I also flushed the transmission while I had the stock cooler off. I used some clear 3/8" hose and ran it into a bucket. I started the truck and while the dark old fluid was coming out I was pouring in new fluid until it was coming out red. Then I installed the cooler, added more fluid, started the truck, and kept adding fluid until it was at the proper level. I think I flushed about 3 gallons (12 quarts) through it to get the dark fluid out. I ended up buying 5 gallons of fluid total (in gallon jugs from Walmart) and I have about a half jug left after the trans was full. If you don't need to flush yours out you won't need as much fluid.

Bought a camper which we started towing with my 2004 Nissan Armada. However, when we started towing, we noticed the transmission getting hot. After researching, I realized that the factory transmission cooler is not big enough, especially for towing, so I looked into an exterior trans cooler. This one had excellent ratings, so I gave it a shot, and it has been amazing. I disconnected the stock transmission cooler, which is in the radiator and installed this external unit in its place. I am so happy I did. Our trans temp has not been elevated since we put this cooler in. It is well built and appears ready to last for the long haul. Could not be happier.

If I could rate this zero stars, I would, My shop recently rebuilt a transmission and installed this cooler onto the customers vehicle. Customer left with vehicle for one week and called to inform us that the vehicle stopped moving. Once the vehicle was delivered to our shop and we performed an inspection. We found that upon the inspection that this cooler had developed a pinhole, due to a failed casting, and the customer lost all of their fluid and burnt up the rebuilt unit. Upon teardown this unit will require $1700 in parts and $1500 in labor. I’ve reached out multiple times to this seller to see if they will help get this customer on the road by covering the parts and my shop covering the labor. They have declined. Why should the customer or the shop have to be stuck with this bill? You expect to have purchased a tested unit. But instead my shop will be paying to fix this hiccup. It’s not the customers fault. It’s my shops fault because we thought we had a good product by a good company and they have unfortunately disappointed us. We will not be doing business with this company again and to them that’s a relief because they get away with this and will continue to sell these poorly made coolers.

I recently had the 700R4 in my 1990 full size Blazer rebuilt. The shop said they flushed out the old trans cooler and lines, but to me they were just raggedy looking, so I decided to replace the lines and cooler to give the rebuilt trans as good of a chance as possible. This cooler was a good price and had good reviews, so I went for it. As you'll see in the pic, it's definitely beefier than the unit that I took off of the truck. I don't know if the previous cooler was OEM, but guessing not since it was held on by those plastic zip thingies. Now for the "fun" part: I expect other squarebody trucks will have the same issue I'm about to describe. This will be GM pickups from '73 to '87 and Blazer/Jimmys up to '91. There is a center supporting bracket that runs smack through the middle of where this cooler needs to go, so you gotta put that thing on a diet. Fortunately the bracket is easy to remove - just one bolt at the top and two at the bottom. Once it's out of the way, just mount the cooler as high up as possible. But watch out for the hood latch - it uses a few inches of space right above the new cooler when the hood is closed. Then just grab the death wheel and chop out a triangle from the bracket to allow clearance for the cooler. Be sure to leave the "lip", since that will need to be bent down and welded to the bracket to give it some structural integrity. Other than that, it's pretty simple stuff. I've taken it on a few test drives and gotten it up to temp, and so far no leaks or other issues. Seems like a good unit, and due to the sheer size of it, plus the larger diameter stainless hoses I added, I expect the trans will be much cooler and happier now.

Works great just DO NOT and i repeat DO NOT USE THE RUBBER HOSES. Will leave you stranded or worse, burnt 4l60 and no one likes that! GET YA SOME BIG THICK GORILLA LINES AND SHE GOOD TO GO HOSS

Installed on a 2016 Chevy Silverado 1500 LS with the 6l80 transmission I just had it rebuilt and I was still seeing the transmission fluid would get as high as 210 which made me nervous I’m in Phoenix so it gets hot down here. It’s December right now and the trans temp would still get to 210, so I got this hoping it would help and it definitely does the highest I’ve seen the fluid get now is 145. It’s very easy to install only took me about an hour. I highly recommend getting a better quality hose I got 6ft of transmission line that’s rated at 400psi and used it instead. Guys the only reason it didn’t get 5 stars is because I inspected the two inputs on the cooler and I saw aluminum shavings still stuck inside one side of the cooler I’ll add photos right now so you can see but I went with a drill bit drilled them smooth and flushed out the cooler just be careful when you get you’re make sure both ports are clear of debris. Last thing you need is aluminum shavings going through your transmission. Other than that I’m pretty happy with this cooler

Got this after seeing the test video on the Half Fixed Garage YouTube channel. The cooler was tested by itself with integrated radiator cooler bypassed. Temperature sensors before AND after the cooler. Fluid cooling of 30-40 degrees while driving and almost 50-60 degrees of cooling at stop lights. Tested in a duramax with Allison trans.