I’ve got a 94 Mazda B2300, 131000 miles.I drive it on the freeway at normal speeds, take my foot off the gas to let someone merge or something and then put my foot back on the gas I hear a load bang. Sort of like a hammer hitting metal. Doesn’t make the sound in 1st 2nd 3rd or 4th just 5th gear. Crawled under and all the mounting bolts / structures appear solid. The drive shaft has about 1/4 inch of play in it with the car parked in neutral (I know it’s not good to get under with it in neutral but I blocked the tires… Is 1/4 inch of play normal…??? Any other thoughts on what it might be…??
Is that a front wheel drive car OP? The symptoms sort of sound like a rear wheel drive u-joint problem. Or a two-piece driveshaft spline lube problem on a rear wheel drive car. But I would have guessed a 94 Mazda would be front wheel drive.
Sounds like worn drive shaft U-joints.
Possibly the pinion bearing, is there any up and down movement of yoke on the differential ?
Parking brake set, tires blocked, transmission in neutral.
A B2300 is the Mazda version of the Ford Ranger pickup. So either the U-joints, or a differential problem.
U-joints are the first thing that came to my mind too.
And you would have guessed wrong.
A B2300 is a Mazda badged Ford Ranger with the 2.3 4 cylinder.