Odd issue


New member
Jun 22, 2019
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I have a 2005 Envoy with the 5.3. My intake manifold decided to blow a couple days ago. After some EXTENSIVE searching I came across a good used one. After installation I discovered a vacuum line was ruptured. I was able to limp the vehicle under barely any power to Oreilly which is just across a major road from me. Installed the new line and when I left I discovered at 30 mph it doesn’t want to shift. I thought it could be my transmission going. I got home put the vehicle in 3rd gear and it moved no problem. Let the truck sit for awhile and then when I went to test drive it around the neighborhood, I could feel the front tires locking up. I put the vehicle in neutral, shifted from 2wd to 4lo slowly letting my front differential shift completely. From 4hi to 4lo there was a loud banging sound. It shifted perfectly fine back to 2wd. When I started to drive again my front differential started to try to grab at 25mph. Is there anyway to fully disable my front differential so I can verify my transmission isn’t going out?