Have a problem with my 190E 2.3 (1993) auto trans..
I am getting a loud ‘clunk’ noise from the rear when shifting to Drive or Reverse from Neutral/Park, a ‘rattle’ noise when letting go of the gas at 50-60 miles/hour or higher, and then ‘clunk’ noise again when starting accelerating.
The front/rear flex disc is new/in good shape.
Checked for ‘slip’/wear of the rear axle/differential; With the rear wheels of the ground, one wheel can be rotated more than a couple of degrees before the drive shaft starts rotating. The right rear wheel is worse than the left rear wheel.
I guess the question is, is this a sure diagnose/confirmation that the differential or the axle shafts are the problem?
If confirmed,
- Is the problem likely to be the axle shafts or the differential or both?
- I have looked around for axle parts and differential parts, but not been able to locate any, neither new or used. Does anyone have any suggestion on how/where to find parts?
I had the same problem with my 1993 2.3 several months after I replaced the flex discs. The clunking noise turned out to be a defective right rear Sub-Frame Mount (front). Note, There are two mounts on each side of the rear suspension...front and rear.
When I jacked up the right rear wheel, I could see where the rubber mount had worn and torn apart, causing play in the suspension. I replaced it myself and it fixed the rear noise problem. BTW, this happened in August of 2003 with 71,000 miles on the car.
Just checked all rear-end mounts, they are are solid.
I guess that I am back to square one!
[?]
CHDFW,
Have you tried having someone shift the transmission back and forth from drive to reverse while observing the rear suspension? You should be able to isolate where the clunking noise is coming from. It sounds like a worn/defective flex disc but you said they are OK. I know these problems are hard to find and can be a real pain.
I have the same problem on mine, and it is worse when it is cold....I have yet to check it personally[V], but it sounds more like the differential than the flex disks..although my mechanic says it's the disk in the rear....(he hasn't really looked either)
On other older cars(soid rear axle, non independant suspension) you could take the wheel and rotor assemblies off the car, and remove the outboard axle retaining plate and shims. By removing some of the shim(s) from behind the outboard axle thrust bearings(making sure that there was still the correct endplay when done), this would allow the axle gears to engage the crown gear more closely(tapered gears)...and take out this annoying play.....
I was looking at the set up on this car and wondering if there is an equivalent adjustment which could be performed?
Yes, MDE3
You are right, the ‘gear play’ can be adjusted.
In the service / repair manual there is a very detailed description on how to do this by changing shims – sizes and move them from the ‘inside to the outside’. The nuts holding the side bearings in place can also be adjusted (i.e. adjusting the endplay). The adjustment should be done by endplay/backlash ‘touch and feel’ and looking at the ‘gear tooth contact pattern’.
It sounds simple enough, but how ‘challenging’ is it really?
Do you need to take the axle shafts off to make the adjustments? One or both?
To measure the endplay/backlash, I found the following guide:
1) Raise the rear end of the car
2) Lock the drive shaft end of the differential (prevent it from moving – turning)
3) Lock the left wheel (prevent it from turning)
4) Turn the right wheel until it is in driving condition
5) Make a chalk mark in the 12 o’clock position on the tire (on the right wheel)
6) Now turn the wheel in the opposite direction until it is in driving condition and make another chalk mark on the tire (in the 12 o’clock position)
7) If the chalk marks is less than One inch apart, the endplay/backlash (slip….) should be within tolerance and should not be the cause of the ‘clunk noise’.
I have not yet measured my BACKLASH, but I will let you all know when I do.
MDE3, I am just concerned about opening the rear differential, what if both the ‘axle shaft gears’ and the ‘differential gear’ are all messed up? How do you replace the ‘differential gear’? Also, where do you find the gears, axle shaft, circlip, different sizes of shims?
How was your past experience?
If you have significant enough gear failure in the differential, you would probably have more noise than just a clunk. Broken gears are pretty noisy, so you would probably have some serious noise to tip you off..
Because you are taking up play from normal wear between the mating gear faces, just moving the shims may well be enough. If there is too much bearing play then they should be repaced anyway. A little play can be taken up by adding a thin shim..shim material can be purchased in sheets and you can cut out some if you are in need. They will collapse under tightening if the edges are a bit crooked.
By removing shims closer to the differential, and putting them on the back side of the bearing, you are maintaining the same total bearing end play as you started with, but allowing the drive axle/gear assembly to approach the pinion gear, and thus take up some of the extra play. So if the bearing play is ok, all you are doing is moving it closer to the diff, and no extra shims are really needed.
To acurately measure the bearing play, do this before starting the shim removal. Use a dial indicator agaisnt some part of the axle which will indicate horizontal movement(along the long axis of the axle). Push the axle in (tap with a rubber hammer to make sure it is fully "retracted", then pull out on the axle..the dial inicator will tell you the bearing end play.
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