Re: 75 driveshaft balancing again

[Charles Slayman <Charles.Slayman@domain.elided>]

Jess,
	I have no experience with the Alfa transaxle cars, so I'm not an expert 
(and I think as the other Charlie would say, "Haven't played one on TV either."  
Or was it Will that said it?  I get our Pasadena clan confused.)  The fact that 
the vibration comes and goes is highly suspicious.  A balance problem is stable. 
 Either it's balanced or not.
	I would start looking at alignment issues.  First, in the driveshaft 
flanges and fingers that bolt to the guibo (did I get it right this time John?)  
But again, any bent flanges would give a fixed vibration problem.  If the 
vibration is truely variable from day to day, then the only thing I can think of 
that would change would be the alignment of the engine with the transaxle.  I 
don't recall any torque tube or torque arm on the GTV6/Milano.  Is it possible 
that the load in the car can effect the alignment of the transaxle with the 
engine?  As more weight is put in the car, is there any stress coupled to the 
mounting bushings?  The weight you have in the car might vary from day to day 
and this is the only thing I can think of that would explain why the vibrations 
would come and go.
	You might want to look for vibration with nothin in the car.  Then load 
it up with a ton of stuff and drive it again.  Any changes in vibration?  I know 
I can detect a u-joint going in my Spider easier with no weight.  Then when I 
load it up, the problem appears to go away (but not for long!)

Good Luck,
Charlie


>From: Jess Liao <jessl@domain.elided>
>Subject: Re: 75 driveshaft balancing again
>To: alfa@domain.elided
>Date: Tue, 9 Oct 2001 11:35:45 -0700 (PDT)
>MIME-Version: 1.0
>Content-Transfer-Encoding: 7bit
>
>I got a few emails with suggestions and questions, let me lay down my
>history on anti-driveshaft-vib movement.
>
>
>When I first got the car, it had very faint vibration.. no big deal 
>I thought.
>
>After my blown the donut at 2nd gear (a typical BANG! and vibration after)
>I had donuts replaced.. and replaced (thought of an unbalanced donut) ...
>the vibration is still there.
>
>After 2 host clamps, things got better, but still significant amount
>of vibration can be felt.. the weired thing is that the vibs comes and
>go.. sometimes better, most other times worse...
>
>So, setup a quest to have drive shaft, clutch, balanced.
>
>Drive shafts were independenly balanced, though the front piece was
>balanced with the front fork in place with marking. The fork was checked
>to be perfectly perpenticular as told by the balance shop.
>
>each bolt and washers used on the drive shaft were weighted to ensure
>equal weight.
>
>clutch assmebly was also balanced independenly. The only exception
>was the friction plate which was left out, and was balanced staticly.
>
>All bolts nuts used for clutch assembly were also being weighted
>to ensure they all weight identically.
>
>When the drive shaft was off the car, the engine was fired up and
>it reves totally smoothly without any vibration when the driveshaft
>was attached, this lead me to believe that the flywheen and the
>rest of the engine assembly is in good condition and well balanced.
>
>upon assembly, the vibration was still present... hose clamps were
>again applied to make the car vib somewhat less....
>
>Since then, the vibration comes and goes just like before.. some times
>worse, some times less... 
>
>I don't remember if the center bearing was replaced but certainly checked
>in the early stage.
>
>This time, with complete defeat of "BalanceMasters.com" project...
>I am again left with a vib that it started since day one.
>
>I think any further I am practically replacing every part in the
>power deliverying system. (Yes, I've tried with a 2nd gearbox so
>gearbox was not the source of vibration.)
>
>So I am marking the end of vibrationless quest, and live with that
>vibration.. til the day it all falls apart...
>
>Jess
>88 Verde Anthracite
>95 LS White
>Silicon Valley, CA
>
>--
>to be removed from alfa, see /bin/digest-subs.cgi
>or email "unsubscribe alfa" to majordomo@domain.elided

--
to be removed from alfa, see /bin/digest-subs.cgi
or email "unsubscribe alfa" to majordomo@domain.elided