Sunday, October 6, 2013

I hear Rattling coming from the driver's side wheel area

What To Check When Rattling noise is heard while driving at low speed and Bumps

Problem noticed on  99 Chrysler 300M that is almost at 200K miles on its original engine and transmission. The engine is in great shape, still purrs like a kitten and barely burns any oil (1/2 quart every 6 months of heavy driving).
Now for few months, I've been hearing and feeling a rattling coming from the driver's side wheel area, mostly while driving at lower speeds or going over bumps.

Got It to the mechanic............
I thought was a suspension issue, turned out to be looseness of my transmission's output/stub shaft, according to a mechanic. The wheel bearings were replaced and supposedly, everything else checks out. The Garage mechanic also said the long CV axle looks like it's in good shape.

The Possible way to fix the issue is to replace or rebuild the transmission, since it will have to come out completely.

Is there any other alternative to repair the problem or to save the repair cost?

As per my inspection the looseness and rattling feels like it is at where the CV axle connects to the output shaft. The output shaft itself does not feel like it is loose inside the gearbox.
I almost suspect the inner connection of my CV axle is worn or the threads of the output shaft may very well be worn.
Is there any kind of coating that can be added to restore the output shafts threads, without having to replace the entire output shaft assembly?  PLEASE SUGGEST SOME EASY SOLUTION?


As per problem described you mentioned that the noise was coming from the left side of the car, is that also the side that mechanic at car garage said there is a problem with the shaft on?

Basic Stub Shaft Assembly:
The left stub shaft runs from the differential on the right side of the trans, though the bellhousing and out to the left side. There is a support bearing at the left side of the case with a large snap ring that holds it in. This shaft takes less than an hour to replace if there is in fact something wrong with it. To check the shaft splines and the bearing you can pop the CV shaft off of it and inspect it.

The right side stub shaft is the one that everyone seems to believe is loose on these and it's a matter of knowing what is normal. Due to the way the trans is designed it's normal to have up and down movement if you grab the inner CV joint and move it.
The excessive movement can be there or its the actual system with that much free movement.This isn't to say you aren't seeing excessive movement, but some movement there is normal and it will be more than you feel on the left side.

To confirm the problem you can  pop the CV shaft off and have a look at the splines. If the splines are ok and there is truly enough movement then the trans would have to come out and the differential disassembled to replace the shaft. As per my knowledge replacing or rebuilding the entire transmission isn't necessary.

If there was excessive movement there then you should see the axle seal leaking and I would expect some vibration on acceleration. If you're feeling and hearing a rattle over bumps I highly doubt it is related to the stub shaft and CV shaft.

One more important thing,get second opinion from another car garage mechanic who is bit professional.
The stub shaft on the left side wouldn't require removal of the transmission at all to replace it. The shop either isn't experienced with this or they weren't wanting to work on your car anymore!They are ignoring the problem.

Try this:----
If you're able to slide under the car with a flashlight  take a closer look at where the shaft goes into the trans. You'll see that the bearing goes into a bore in the trans, the bearing is roughly three inches in diameter. Around the outside of the bore is a snap ring, this is what holds the entire stub shaft in.

To remove the shaft:
First remove the tire and then the strut clevis bolts. This will let the top of the steering knuckle swing outward enough to get the CV shaft off of the stub shaft.

Knock the shaft off of the stub shaft and then the snap ring can be removed.

Then only you can pull the stub shaft out. There is a special tool that can be used with a slide hammer than grabs the shaft by the retainer ring groove on the end. Due to age and corrosion I've seen some of these stick pretty bad my personal experience and sometimes you have to use a hammer and punch or air hammer to get the shaft out. Another method if replacing the shaft would be to weld a large slide hammer directly to the stub shaft if it gets to that point.

If it comes apart correctly then the entire shaft and bearing can be replaced in less than an hour.

How To remove Transaxle?

Click here for Transaxle Removal & Installation

Click here for Automatic Transaxle Replacement

Click here for Cv-joints Overhaul/removal/installation