drive shaft

#$%&ing done... :D :D :D

Thank you Isaac :D

So, I think it went fairly smooth, once the new shaft was in, there was a rubbing issue, but adding some washers to the rear tank straps solved that.

Here is a pic of the new shaft...

2374767420039881733S600x600Q85.jpg


And yes I own a bicycle, and no I don't actually ride it...

BTW, those are the the little, big, and really big coolers... non of which will fit in the MK8... :rolleyes:

The old shaft was badly scored from the simi-metal mat thing that sits above it, I'll take pictures of that later.

Anyway, got it up to 65 in the neighborhood tonight, no vibration at all...

Highway test tomorrow will be the true deciding factor, but so far I'm pretty psyched. :D
 
Sorry, I snuck a peek slightly to my left...

So basically, to expound on the mat, the sheet of sound deadening material had basically let go at one end and was partially held up by a clip at one end. The foil on the bottom of the mat had basically acted like the driveshaft was on a lathe and literally carved very shallow grooves into the shaft in 3 major places. This no doubt contributed to the vibrations by throwing off the balance. Tomorrow we're going up north a ways for me to check out a Mountaineer, so we will see how much better the Mark can waft now. :)
 
So having just driven up the highway for distance, the grey car is now smooth as glass up to 110... :D traffic prohibited testing at higher speeds. :D

It is nice to be able to see things out the rear view mirror when going 80 or better... :D
 
BadSax said:
So having just driven up the highway for distance, the grey car is now smooth as glass up to 110... :D traffic prohibited testing at higher speeds. :D

It is nice to be able to see things out the rear view mirror when going 80 or better... :D
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...Like DB9s! :D
 
driller said:
Being the curious type (and quite familiar with industrial bushings), what is the press fit interference between the bushing and the tailshaft housing?

Depending on the tailshaft housing tolerance, you could easily see 0.0015" diameter reduction per inch of diameter just from the interference fit with the housing. ADD 2 to 3 times that for thermal expansion fluctuations and suddenly a comfortable 0.010" fit is 0.005" or less - dangerously tight depending upon lubrication and load. But I agree 0.050" is ridiculously sloppy for a new bushing in an application such as this.
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It was a while ago, I can't remember the interference number. I knowI got it close to the OD of the old bushing then knurled the outside of the bushing just for some extra interference. I know I went through a few iterations of pressing it in, measuring it, then making some minor adjustments on the lathe and putting it back in.

I know I made it fit tight, but from my grandfathers advice (a machinist) I left the clearance around .002 or so I believe. Then I did the forced lube mod to ensure lubrication of that tight fit. The car has been used in very cold winters and hot summers with no issues or loosening.

Also, I remember when measuring the yoke diameter it was something X.X98 which my grandfather also thought 0.002 of clearance would give you a nice round number for the bushing ID ;)
 
Joe, did you change the tail shaft bushing?

Anyone...how is it removed? does it just slide out or is there a special puller?
 
95blklsc said:
It was a while ago, I can't remember the interference number. I knowI got it close to the OD of the old bushing then knurled the outside of the bushing just for some extra interference. I know I went through a few iterations of pressing it in, measuring it, then making some minor adjustments on the lathe and putting it back in.
Click to expand...

You can bet that is where you have succeeded in making a customized fit for your application. I would say that manufacturing tolerances preclude the use of such a tight running fit. My guess is the overall tolerance is likely more than 0.002" by the time you add tolerances on the diameters for the bushing, tailshaft bore and yoke.

Without knowing load and rpms, I would say 0.002" would be the lower end of the scale for this particular running fit. The forced lube mod was definitely a good choice for your application.
 
Those are good numbers from my recollection of what the parts were originally machined to. The bushings themselves were outside vendor items that were pressed in only.
 
Roadboss said:
Those are good numbers from my recollection of what the parts were originally machined to. The bushings themselves were outside vendor items that were pressed in only.
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Good to hear! Like I said I'm not a machinist, just know the basics from my grandfather. He gave me a couple of pointers while I was making it, in the end it worked out good. Still going strong years later and about 70k miles.
 
izackary said:
Wrong immunity phrase. If you'd said "no homo" I'd grant you the benefit of the doubt. But you didn't, so you're totally a fan of the shaft. :D
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LOL Izack, I was gonna use "no homo" but I wasn't sure anybody would know what I was talking about.


Gravelguy, how much quicker is the acceleration with the 4.30 gears. I want to do those later on in the far future. Its gotta be .3 to .5 seconds quicker in the 1/4 mile.
 
Grandpas' Rule!!


95blklsc said:
Good to hear! Like I said I'm not a machinist, just know the basics from my grandfather. He gave me a couple of pointers while I was making it, in the end it worked out good. Still going strong years later and about 70k miles.
Click to expand...
 
beerdog said:
Joe, did you change the tail shaft bushing?

Anyone...how is it removed? does it just slide out or is there a special puller?
Click to expand...

No we didn't change the bushings, and the rear seal was replaced right after I got the car back to CC...

Here are some shots of the old shaft...
btw, the "I'm a professional drunk" sign, I scored off a homeless guy in Boston... :D
2500066850039881733S600x600Q85.jpg


This is the thing that was rubbing on the drive shaft...
2438303030039881733S600x600Q85.jpg


Here is how much metal had been rubber off...
2599096990039881733S600x600Q85.jpg
 
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