CK5 - The Full-Size GM Off Road Community

Hi guys,

My truck makes a very loud and sometimes violent klunking noise (and bang) if I don't really 'play' the clutch when I shift gears. It is a 1972 Blazer with a SM 465. It has done this since I bought it three years ago but I am used to it. It even did it on my test drive. When other people drive it the bang is loud and you can feel it through the floor. When I was getting it emissons tested I watched the rear drive shaft really bounce up and down when the dude shifted gears. As for the tranny, it stays in all four gears, though the stick vibrates a little when it is in third.

Has anyone else had a similar problem? Any suggestions as to what it might be?

Thanks again for all your help,

Rod

If your driveshaft jumps up I would think it would be the transfer case mounts. Try and put a jack under the transfer case and see how much it moves.

I just got through searching for the source of clunking on my 350/350/205 equiped 72 K5. Turns out my rear driveshaft yoke on the 12 bolt was loose! The pinion was fine, so I just tightened the 1 1/8 inch bolt that holds the yoke to the pinion.

My point...check your driveshaft yokes.