I have a large disc on my transmission output shaft for a parking brake, with a manual caliper and a lever.

A friend of mine has the same setup, except he has spring set air release brake chamber to operate it. With the flip of a switch it locks the driveshaft solid. If he were to drain his air tanks a thief would have to start the truck and wait for the tanks to fill and find the air switch for the brake. Or bring their own air tank and figure out how to release the brake chamber. Or cut/remove the driveshaft, or remove an axle shaft. Or lift the back end up with a wrecker and tow it away.

I may eventually use an air disc brake setup from a medium duty truck on mine..

Another theft deterrent is weight, try pushing an 8,000 lb truck around.

I still think that if someone really wants your truck you can't do much to stop them, you can have fun trying to outsmart them though.

Grigg

•1951 GMC 250 in the Project Journals
•1948 Chevrolet 6400 - Detroit Diesel 4-53T - Roadranger 10 speed overdrive - 4 wheel disc brakes
•1952 Chevrolet 3800 pickup
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"First, get a clear notion of what you desire to accomplish, and then in all probability you will succeed in doing it..." -Henry Maudslay-