[W126 Coupe] ... fix one problem - find another

[Alexander Hochhausl]

Gents,
 
Does anyone know if the rear pinion input shaft bearings are adjustable?
My manual (CD) does not cover the rear at all! I'm hoping it's possible
to do this from the input side - I really don't want to take the whole
thing apart. I have a new input sealin case I need to replace that.
 
Reason for asking: My drive shaft bearing mount was shot (ripped apart)
- BTW manuf. Name is Meyle . OEM? Anyway, was only 3 years old & came
pre-mounted on a reman. Drive shaft. I knew there was a problem because
each time I left a light I'd hear a few "clunks" from under the car.
Well I replaced the bearing (in 2 hours - new record for me, not sure if
that is a good thing) - now the clunking is gone ... BUT .. Between
30-50 MPH I have one hell of a harmonic vibration from the drive shaft.
It is a high frequency so I know it's the shaft. I double checked the
shaft alignment - it's right on - I know it's not the shaft itself
because the vibration is only when I'm on the gas (I also made sure it
is stress free - free floating length). Coasting and  0-30 & 50-120MPH
is perfectly smooth - no vibrations. If it were the shaft I'd expect it
to repeat from 60-100 (+/-). I know the bearing on the rear pinion input
shaft has some play. My theory is that when I'm on the gas, it goes
off-center - forcing the drive shaft to oscillate - which builds a
harmonic in the carrier bearing rubber mount.. Sorry - I am Mechanical
Engineer - so I get deep into these things. My other thought is I'll fab
a solid rubber mount - I did that on my 380 SLC which solved the same
issue, but I realize it's a bandaid - not solving the real issue.
 
Anyone have any thoughts or experience with this problem - am I barking
up the wrong tree? 
 
BTW: Sorry Jonathan. I waited until Wednesday but I did not hear from
you regarding the bearing & mount so I had to buy it from someone else -
I had to have it by Friday. I hope I got a good part - looks OK. Next
time I'll give more head-up. Thanks for offering to help & the info is
appreciated.
 
Thanks All,
 
Alex H
 
89 560 SEC
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