4AudiQ

<img src="http://pictureposter.audiworld.com/81050/img_1038.jpg">
10-6-06 Here is where it started: a used 4000KQ Drive Shaft with center support bearing.


<img src="http://pictureposter.audiworld.com/81050/img_1051.jpg">
10-9-06 I had both the spline ends cut off. These were sent off to Mance along with the measurements he enumerated.


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1-10-07 - The measuring process began with removing the exhaust, heat shields and we get down to the drive shaft itself, seen from the transmission back and then from the final drive forward.


<img src="http://pictureposter.audiworld.com/81050/img_1127.jpg">
1-11-07 - Tip #1: when loosening the bolts that hold the CV Joint onto both the transmission and final drive, heat the bolts up with a propane torch to soften the red Loctite which the factory puts on the end of each one. They are in there very tight, but the softening of the Loctite makes it much easier to break loose.


<img src="http://pictureposter.audiworld.com/81050/img_1130.jpg">
Tip #2: There are 6 bolts holding the CV Joint to each end. Loosen the ones (usually
3 - 4) that can be easily accessed. When those are loose, jack up 1 rear wheel and turn the drive shaft to give easy access to the other 2 - 3 bolts. Don't struggle like I did in trying to reach those on top of the CV.

At this point in the disassembly, I had removed all 6 self-locking bolts in the transmission end and the final drive end, removed the center support bearing Hex bolts, but the whole assembly did not drop. I was not sure why, so I called Tim at Beach House Imports and he sent over Ty, one of his great employees, and he brought a hammer and a steel rod and banged real hard maybe 20-30 times on each end until it finally dropped. It must have been rusted into position.


<img src="http://pictureposter.audiworld.com/81050/img_1129.1.jpg">
Here is my make-shift drive shaft support mechanism. The factory suggests you lower the drive shaft as 1 piece with some kind of support underneath it. Of course, they were not expecting us to replace their design with a better design, so they expected us DIY'ers to put the 2 piece drive shaft back in place.


<img src="http://pictureposter.audiworld.com/81050/img_1185.jpg">
2-6-07 Install Day. The CV Boot goes on first, then the CV Joint (notice the groove goes toward the transmission or final drive, not toward the inside of the drive shaft). I used Nickle Anti-Seize on the splines because I have future plans to put in light weight CV's, thus I will have to take off these old CV Joints again. The CV Joint must be driven onto the spline ends(I used a 6" piece of 2 x 4) and then driven just a little bit beyond the end of the spline to accept the retaining ring. I used a 1" socket to drive the CV Joint past the retaining ring slot. You can see that clearly in this next picture.

<img src="http://pictureposter.audiworld.com/81050/img_1188.jpg">


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This is the transmission end.


<img src="http://pictureposter.audiworld.com/81050/img_1190.jpg">
This is the final drive end.


<img src="http://pictureposter.audiworld.com/81050/img_1195.jpg">
I used the center support bearing bolt area to hold the 1 piece drive shaft somewhat in place as I began to attach both the transmission end and the final drive end.


<img src="http://pictureposter.audiworld.com/81050/img_1192.jpg">
I am just beginning to attach both ends. I got each end started and tightened one end a small amount, then went to the other end and tightened that end a small amount. I kept working both ends alternately until I was ready to torque them at 41 pounds. A glitch came when I tried to use the new backing plates(they connect two bolts together - you can see one clearly in this next picture).
<img src="http://pictureposter.audiworld.com/81050/img_1198.jpg">

The new backing plates were about 2mm smaller than what was on the car, so I had to use the old backing plates.
When I returned them to the dealer, the parts man found the original number was superseded,
so we could not tell if the backing plates were correct or not. The parts man said someone may have emptied these into the wrong bin at the warehouse. Tip: do not throw anything away as you disassemble because you may have to re-use an old part. My Bentley says specifically to use new self-locking bolts, so those must not be re-used. I had a mechanic tell me if the gaskets were is good shape, do not replace them, just re-use them.


<img src="http://pictureposter.audiworld.com/81050/img_1197.jpg">
<img src="http://pictureposter.audiworld.com/81050/img_1198.jpg">
Here is the final pic of the CV Joint's at both end installed and torqued down to 41 pounds. I did manage to round-out one of the bolts on the final drive end, so when I install the new light weight CV Joints that I will purchase from Mance, I will have to use my new Craftsman locking pliers to take that self-locking bolt out(I will use the propane heating method to ensure it comes out).
Next, I reinstalled the 2 heat shields, cross member that will act as a safety catch in case the drive shaft comes loose. Put the exhaust system back in and backed in down the ramps.

My initial impression: it seems to rev quicker, it seems to get going quicker, which it should if it is rotating less weight. The V6 12v has always been a dog off the line &amp; this one mod has not changed that fact significantly. I am pleased with the mod and would recommend it.

AudiSport4000

My center bearing is toast on my 4kq. I have a replacement BMW bearing, but if I could go to a one piece driveshaft that would neat and more effective in a few ways.

Would it be worth it in my situation?

teach

It would seem to me, though, that the original flexible shaft saves torque on the two ends: tranny and rear diff. In an ideal world the whole thing (both ends) would be perfectly aligned and the mounts would absorb any movement....but were the two ends even perfectly aligned when leaving the factory?

I am sure this has all been discussed...but it's the first I've seen of this. You did a super nice job, and I understand the desire (less rotating weight).

What is the difference in weight between the two shafts?

4AudiQ

Drive Shaft Costs::

Add 3 exhaust flanges $70.00
Stainless Steel Bolts for flanges $6.25
CV Washers, plates &amp; bolts 103.57
SS Strap Bands for exhaust 26.95

Plates &amp; CV Grease $17.10
OEM Exhaust Clamps $66.73
Light Weight Drive Shaft $425.00

Credit for plates &lt;18.62&gt;

$696.98

You have to determine if it is worth it. In my case, YES!

4AudiQ

The 2 piece = 14 lbs.
The 1 piece = 10 lbs. (at the factory).

Cq20V

the only degree of freedom that is removed is the universal joint at the middle, which a lot of people claim is mostly there for crashworthiness, so the DS folds up in a crash or if a CV joint falls apart, rather than pole-vaulting the car.

Merkin

nah, it's for saving money during assembly

Cq20V

How.

Merkin

with center bearing they could just slip everything in and impact the bolts within seconds.

straight shaft would require manuvering.

Cq20V

Define "manuvering". What maneuvers did 4AudiQ have to do?