Gagsu Low Pressure Drop Transmission Oil Cooler LPD47391 4739 40,000 GVW with Mounting Hardware (Black)

Great cooler but crappy hose. Would recommend getting a stainless steel braided hose and fittings to make it more reliable. I blew the hose after one day. The fittings held but the actual hose failed.

This cooler dropped the transmission temps down on my wife's 2011 GMC Yukon XL Denali to 140-150 degrees steady in the summer heat. Installation required a little creativity. Watch some of the videos online for installing a 40k transmission cooler and adjust as you see fit. I did try to install this cooler with the original hard lines, but could not bend them without feeling like I was about to kink the line and reduce flow, so I wound up installing the cooler with hoses that I slid over the original hard lines. I did heed the warning of the other reviews and not use the included rubber hose and bought some elsewhere. In further research I saw people recommending to install the fittings facing up, however I have not seen any evidence that this is absolutely necessary, but may do so one day.

Decided to do this last minute upgrade before a trip that involved towing another long bed truck with both trucks fully loaded in the bed and cabs(helping my old man move two states away). I started by checking my trans temps at highway speeds with the original cooler without towing anything. I peaked at about 180 degrees going uphill without the engine screaming. After doing the swap I started my journey, truck empty towing a small enclosed trailer also empty. Never saw the temps go above 135 degrees til I reached my destination. On the way back fully loaded down I peaked at 152 degrees on a steep uphill under heavy load and engine giving her all she had. I am very much pleased and relieved that I put this in when I did. I very much recommend it to anyone. As a side note if you haven’t already. Make sure to bypass the trans cooler that’s built into the radiator. They are notorious for failing and causing your fluids to mix in ways they shouldn’t. Just add rubber hose to your factory cooler lines with some clamps and run it out front to the cooler.

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.

Solved all my overheating issues! This is after riding around on a hot Louisiana day!