Clicking\cracking noise?? U-Joints???

[HALSTEADTW]

I've got a 1995 mustang GT with 136,000 miles on her. The last month or so I started hearing a faint clicking noise when accelerating in 1st or 2nd gears. The noise appears to be coming from under the seats, but it is hard to pin point cause it only happens when accelerating like I said. Well this noise has gotten increasingly worse and ticking or clicking noise is loud now!

I know what spark knock is and this noise sounds similar but it is not coming from the engine.

Does this sound like one of the u-joints on the drive train has gone dry of lubrication? I've tried to feel the play in the drive shaft and there seems to be a small amount of play but nothing huge.

Any help guys, this sound is driving me crazy

 

[HerkyJim]

Maybe. Usually the first indication of a u-joint going is a slow regular tick while decelerating at very slow speeds. I remember my '69 Ford: If I opned the door a little while coasting into the drive way I could hear alittle "tick" "tick" "tick" about two per second. My Plymouth right now has at least one bad u-joint and I can hear it "clank" when shifting from reverse to drive or vice-versa sometimes. There is not much driveline angle and I drive like the old man that I am, so its not urgent that I fix it. But, then a front u-joint failure could be escitong if it digs in or catches apothole, and a rear u-jiont failure and lose the whol;e driveshsft in traffic on the freeway at 70 mph could up your insurance premiums a bunch. They don't cost much and aren't too difficult to replace usually.
My$0.02

 

[Mud]

Finding the source of noises can really be a pain sometimes.

Is it possible that the noise may be coming from the brakes? Sometimes the pads/shoes start clicking/clattering. It does not necessarily mean that they are worn out, but they may need some lubrication at their mounting points, new spring clips, etc. Maybe drive the car and see if the noise stops if you apply the brakes, even while you are accelerating.

However, on a stick shift with over 100K miles, you should consider replacement of the u-joints as a point of maintenance, regardless of the source of the noise.

 

[Tosh]

Well, you could certainly rule it out (and accomplish something useful) by repacking or replacing the U-joints.

 

[mechtech]

U joints should have no play in them.
If thee is any slop at all, they are toast.
Make sure you aren't feeling the differential gear backlash, or spline looseness at the trans.

 

[Mike_dup1]

U-Joints often dry out and they start to wear.

I recall having one go bad on my truck last year, I kept hearing a snapping noise when taking off or shifting gears. It was at the rear axle..

 

[Jim 5]

All the comments above are accurate. Just to clarify Mechtech's comments as to how you would check for this:

1. To check for play at the U-joint, get underneath the car with the car in neutral (exercising appropriate saftey measures). The U-joint connects the driveshaft yoke on one side of it, and the differential/pinion yoke on the other side. Hold the diff/pinion yoke firm and try to rotate the driveshaft back and forth. If there's any slop, replace the u-joint. If there's no slop, as mechtech pointed out, you need to check for looseness in the diff (gear backlash).

2. Checking for gear backlash requires the rear wheels not to move. Apply the emergency brake or have both rear wheels on the ground with the car in neutral. Assuming no problems in procedure 1 above, then you grab the driveshaft and twist. Any slop at this point will be in the diff. If you have no slop here, check the transmission for output shaft/spline slop.

3. Assuming no problems found in 1 & 2 above, to check the trans/spline for slop, you'll need to get the back wheels off the ground with the emergency brake off, and the transmission in gear. Now twist the driveshaft again back and forth. If you feel any slop or "backlash" now, it's in the output shaft/splines of the transmission.

I think the above is pretty accurate, but I'm open to comments. Hope this helps.

 

[Jim 5]

By the way...if you leave a bad u-joint in too long, it can frag is bearings/caps and start banging against the yoke, ultimately enlarging the hole in the yoke, requiring potential replacement of the pinion or driveshaft.

I've had this happen a few times in my trail rig at the front axle shafts. It definitely sounds like a clickey clack or ticking usually somewhere between accel and decel. When you're on or off the gas, the accel or decel closes this gap.

Something to be aware of.

 

[HALSTEADTW]

Just to let you guys know, I ended up taking both u-joints off and the front ujoint was dry and full of rust on one set of needle bearings. Thanks for the input!