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Loud noise when slowing down


cshaw9

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Hi. I've put about 300 miles on my car since putting back together the engine and driveline and am now having problems with a loud noise coming from the rear of the car when slowing down.

At higher speeds (like 3000 rpm in 4th gear) the sound comes with even a slight slowing of the car, like backing off slightly on the throttle, or pressing the clutch, so that the engine isn't driving the wheels anymore. The sound goes away as soon as I increase the throttle slightly.

At low speeds (like coming to a stop at a stop sign), the sound is periodic, and sounds like it's coming from the left side of the car, and sounds very "creaky".

The sound is only when the car is in motion (idling and revving the engine at rest is ok). The sound comes in any gear (neutral to 4th), and doesn't change based upon the clutch.

The transmission is mounted securely, and there is no noticeable vibration in the driveshaft. The center bearing and flexible coupling are both new. The problem didn't appear for the first 200 miles, so I don't think they're the problem.

I suspect the rear left wheel bearing. At one point I took off the castellated nut at the end of the axle, and I'm wondering if there is a torque specification in putting it back on? It seems like if the wheel is speeding up, then there might be a force that seats the bearing well, but when the wheel is slowing down, a force acts in the other direction, unseating the bearing, and hence the noise? Does this make sense to anyone?

Also, what socket size is used for the castellated axle nut? Looks like a 35 or 36 mm?

Any input would be appreciated.

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the torque spec for the axle nut is pretty high, around 260-280 lb/ft. if you didn't torque it down with the proper tools, that might be the cause.

did you put the cotter pin back in the axle? has it moved or sheared since you've been driving?

a bad wheel bearing will change pitch as you load weight to the side with the bad bearing. so when you are turning, the noise will change depending on which side you load.

'74 turkis 2002ti(-i)

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Hi. I've put about 300 miles on my car since putting back together the engine and driveline and am now having problems with a loud noise coming from the rear of the car when slowing down.

At higher speeds (like 3000 rpm in 4th gear) the sound comes with even a slight slowing of the car, like backing off slightly on the throttle, or pressing the clutch, so that the engine isn't driving the wheels anymore. The sound goes away as soon as I increase the throttle slightly.

This "sounds" like the input pinion on the diff... you got oil in it? :)

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You seem to think it's not the driveshaft but I'll throw this out anyway. Make sure that the nut connecting the two pieces of the driveshaft right at the center support bearing is tight. Mine came loose a little while back and made noises at the exact same times you are mentioning.

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Guest Anonymous

Check the rear diff while you're back there. If the sound is there when you are coasting and goes away as you press the gas pedal, that could be a possibility. Ask me how I found that out!

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i just installed a 3.91 lsd from an e21 and noticed more noise coming from the rear end. i installed a poly diff hanger and thought that i might be additional vibration but want to make sure that it is nothing serious.

mike r

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