[AC Promotions]

I have a spare GM cooler assembly that was never used. It has a few minor dents (from shipping) in the spiral coolers but nothing that would be anything but cosmetic. A new cooler assembly retails for $1,588.17 and sells for $1,289.60. I am willing to let this go for $800 plus shipping. Please note that this could be used as a spare for an owner that has the full rear differential kit (PN 20826071) or as a part for someone putting together the kit. These are fabulous rear differential coolers and were put on all V2's headed to Germany and the UAE. The Weldon based pump is extremely quiet and the cooler will stop the dreaded idiot light in the dash from coming on and extend the life of any rear-end assembly as there just isn't enough cooling for spirited driving. Contact me via a conversation if you need the cooler installation guide or the contact information for the person at Cadillac Racing that sells the parts you find difficult to source.

 

[emperors6]

Is the entire assembly easy to get and install?

 

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Yes,

The contact is Bob Herbers, email [email protected], phone 810-239-4122.

The last price a forum member was quoted was $2201.95 (that price hasn't changed since 2013 and included the cooler assembly that is advertised here).

I have been told by a few forum members that Bob will sell individual pieces out of the kit but its best to just call him and get quotes.

There are a few threads under rear end when you search for OEM Differential Cooler or Differential Cooler.

The hardest part of the installation is putting in Riv-Nuts. Unless you have very strong hands (or a buddy who does) getting a regular Riv-Nut gun to pop in the Riv-Nuts is a pain. You have to use GM's supplied paper template to locate where to right-angle drill and drill for putting up the cooler assembly (see diagram above). Two holes already exist in the underbody. The rest is not difficult; just take your time and follow the instructions (so for example, the hoses are all a push-lock design in and out of cooler and pump and everything is engineered to GM specs to handle desert environments). PM me is you want the installation instructions.

if I can't sell it then I will try to use it in my LT4 Pro-Touring build as the Ford 9 center section was built with an internal oil pump (so I need a heat exchanger although one this long would be a challenge to package).

 

[emperors6]

Thanks for the extra details! I was asking since I actually have the WeaponX diff cooler, and wanted to see if the OEM was a cleaner install. However, at that price it doesn't make sense for what I'm thinking. The diff cooler actually no longer kicks in anymore as I stopped tracking the CTS-V a long time ago and the diff fluid doesn't heat up anymore. I'm thinking of removing it but like the option of still having it in there.

 

[AC Promotions]

Understood; I once drove about 350 miles to an open road racing event and someone with a WeaponX diff cooler made the same journey. On long interstate runs in hot weather both of our coolers came on multiple times. Those were at speeds between 70-85 mph. Elevated speeds (such as open road racing, the Autobahn, road racing). cornering and elevated ambient temps will turn on both coolers. Leave it on unless you never plan to hit the interstate in hot weather or it's just used for drag racing (IMO).

 

[emperors6]

I have done many long highway trips at 70-80mph for hundreds of miles (500+) and haven't noticed it turning on. The manual override works fine. I wonder if I should check the thermal switch works. Is it easy to test?

 

[AC Promotions]

I’m not familiar with the WeaponX thermal switch but you should be able to contact WeaponX for instructions on how to test it? Or post a thread under rear end; maybe someone has test instructions. Sounds like you need to use the manual override every hundred miles or so on the interstate until you get it fixed. The GM cooler is connected into the ECM; no manual “on” switch and I doubt an aftermarket tuning software touches that functionality. My Cadillac Racing contacts haven’t mentioned a failure and we both know they beat on the V2’s hard at the V-Academy(which is where the majority of coolers seen on EBay came from after Cadillac auctioned those V’s off).

 

[emperors6]

I'll reach out to Jim (who built the kit) and see if he has any thoughts. The counterpoint that nothing is wrong, is that when going on the track the diff cooler did automatically turn on. However, even when that was happening, it never turned on automatically on the highway driving to the track. I guess it never got hot enough on the highway. I'll get some permanent temperature indicating stickers and see how hot the diff actually gets on the road.