The 1986 GMC Jimmy was made for the long haul, but if yours has been around for almost four decades, chances are the engine, brakes, and suspension need some love. Whether you're working on the 5.0L V8 or 6.2L diesel, keeping up with regular oil changes, cooling system maintenance, and ignition system upgrades is key to long-term reliability. A lot of Jimmys from this era have sagging leaf springs, leaky door seals, and soft brake pedals—fixing these can make your truck feel brand new again. And if your automatic transmission is slipping, a fresh filter and fluid change might bring it back to life. Classic Parts Pro will be your go-to for Jimmy parts soon—sign up for the newsletter so you don’t miss out!