Drivetrain diagnosis help please !!

[revhigh]

Hi All !

My daughter's 2002 Protege LX just developed a noise in the drivetrain (I think). Here's the symptoms.

When the car is coasting with no throttle input, the car has developed a pulsating light grinding sound that seems to be coming from the driver side front (the slower the speed, the slower the pulse). It is most pronounced (or at least most noticeable) from 30 MPH down, as when coasting to a stop sign. Shifting the car to neutral has no effect on the noise, however, applying EITHER the throttle OR brake eliminates it. I'm thinking it could be the driver's side half shaft. It DOES NOT do the standard clicking that most failing half shafts make upon turning.

Can anyone help me with this issue ? The brakes are fine, not worn out, and the car performs as before in terms of acceleration, it also brakes effectively, so I don't think it's a brake issue.

Thankfully, my daughter heard it right away (she's a great kid), and brought it to my attention immediately, as compared to some kids who would just keep driving it.

If it would be a half shaft, are there any tutorials, or how-to's to replace one yourself, or is it a dealer/mechanic fix. I do almost all repairs myself, and have almost every tool imagineable except for specialty automotive tools, and I'm not afraid to tackle a half shaft if it can be done in the driveway or garage.

Any ideas ?

Thanks

REV

 

[dmention7]

Could be a wheel bearing.

Try jacking up the front end of the car, put it in drive, and see if you can locate the source of the noise that way.

 

[revhigh]

I'm thinking wheel bearing too. I removed the driver side front wheel, and removed the caliper and the brakes are fine ... about 50% left. It's getting dark now, so tommorrow I'll remove the passenger wheel, check the brakes there too. There is ZERO wheel play on the driver side when jacked up, either at the 12 and 6 oclock position, OR at the 3 and 9 oclock position. The wheel itself is solid as a rock.

REV

 

[cougar10agREDUX]

check the dust shield for the brakes as well, it could be slightly bent and rubbing.

check the runout of the rotor as well.

the fact that it goes away when accelerating as well makes me think it might be in the transmission. how many miles on the transmission, and when was the last time the fluid was replaced?

 

[revhigh]

Update !!

Well, I tore it apart, removed the spindle nut, caliper assembly, seperated the tie rod ends, seperated the lower ball joint, and pried the half shaft out of the transmission. Supposedly the half shaft's spindle should 'tap right out' of the steering knuckle and hub. Yeah ... right. I took the whole thing to the bench, and literally POUNDED on the end of the spindle with a 10 pound sledge. No movement ... I mean ZERO MOVEMENT. Next .... heavy duty wheel puller ... no movement .... ZERO MOVEMENT. Finally took it to a mechanic who attempted to punch it out with a heavy duty air chisel type gun ... he's never seen one not come apart with that approach ... no movement ... ZERO MOVEMENT. Over to the 25 ton press ... set everything up with super heavy duty truck type press plates ... they started to BEND under the pressure .... but finally it moved ... 1/4 of an inch. After that it was standard pressing and off it came. I have NEVER seen anything withstand so much pressure before. It looks like the splines were rusted to the hub splines, even though they were covered with grease.

Damaged the trans seal when prying the half shaft out of the trans, so had to replace that. Everything went back together in about 20 minutes from that point on.

Problem solved ... no more grinding noise. Just goes to show that a half shaft doesn't have to click around turns to be bad.

REV