Cooling to the Duramax - Transmission Cooler, Part 2: Measure Twice
No matter how many trucks I write about, I'm always surprised how often a critical part of the drivetrain is underdeveloped. It's even more surprising when a truck built for towing and hauling has a major flaw in the transmission system. The transmission is the heart of towing, and when you're asking it to carry over five tons of truck and trailer up a grade, any weakness in the system is sure to show itself. However, the Allison transmission mated to 2001-2014 Duramax engines is not that weak point.
The transmission cooler equipped on the 2001-2014 Duramax trucks could honestly be described as "dainty." That's not a word that any owner wants to hear when talking about a part of their truck, especially not a part they rely on to keep driving. In 2006, when an extra gear was added to the Allison transmission, Chevy/GMC equipped a larger transmission cooler but, for some reason, decided to tuck it behind the bumper. Neither iteration of the stock transmission cooler is ideal, so we're making one that is.
With the stock coolers evaluated, Steve measured the space available for our cooler as well as the routing of transmission fluid lines. Instead of breaking out his pen and pencil, Steve decided to go high-tech with our Faro 3D scan arm. The Faro arm swept across the front of our volunteer LB7, every detail rendered on Steve's computer screen. A few more scans of the transmission cooler alone gave Steve most of what he needed.
There was some manual measuring required, however. We knew that there were two different coolers made for these trucks, but not that the inlet and outlet fittings were the same. Time for the caliper and notepad. Removing the fittings from the cooler revealed two major facets of the fitting, the inner diameter and threads. Steve carefully measured, making sure to capture every detail that we would need to be sure our cooler fit without a hitch.
Those measurements completed the analysis of the LB7 cooler, but we didn't stop there. Over the next few weeks, we scoured OEM drawings and brought trucks into our engineering facility to take more measurements. With every generation of Duramax from 2001-2014 examined, we needed two different fittings and three different hose sets to fit our target vehicles. The hoses were no problem, but the fittings would be a bit of a challenge. Of course, Steve had a plan to join our cooler with the quick-disconnect lines. In the next post we'll see that plan come to life and look at the heart of our design: the core.
Thanks for reading!