Best way to measure axle length needed
 

Hi

The Aussie dollars is up against the Greenback again so I'm going to order some axles for my car, 1303, G50 moved forward 100mm with alloy 944 arms.

What is the best way to dertrmine the correct axle length to get, do I measure from the centre of the plane where CV bolts on?

Steve

I've heard the off road guys cut a axle in half and slip a piece of tubing over it, and bolt it to car w/cv's mounted, set the car at ride height, tack weld the tubing to the axle, and go through full suspension travel to check for binding, if good... remove and measure axle.

awesome way to do it, provided you have axles that can be sacrificed in the first place...

steve, great timing as ill have to do this shortly also

There are a few methods mentioned on the off-road section of shoptalk... You can either measure flange to flange and deduct a small amount, or use a broomstick handle and cut that down until it is at a length that doesn't bind.

don't spend unneccesary cash: Just get a pair of T3 axles and be done with it!
Those are 53cm IIRC and are just long enough, even for more than perpendicular axles.

JFYI ;)

Hi Wally

Thanks, I didnt say in my original post that Im using 28 spline 930 CVs so Im going to need custom axles, CIP has soem at a good price.

Whats a IIRC?

Founmd these instructions the swayaway site,
Sway-A-Way, Inc
9555 Ownesmouth Ave, #9
Chatsworth, CA 91311
818.700.9712
Axle Length Measurement Instructions
Make a Set Up Axle:

The best way to measure your car for axle length is to use a set up axle. There are several ways to do this.

You can cut and sleeve a stock axle or any old axle that has the proper splines on it. A friction saw works

well to cut the axle in half. You can use a piece of angle iron to sleeve the axle. Cut it so that it is about 6”

shorter than the straight across flange-to-flange dimension. Use some hose clamps to hold the cut ends of

the axle in the angle iron. You can now adjust the length of the axle.

Measurement:

There are two positions that should be checked for proper axle length. One, the most important, is at full

droop. The other is at the straight across position.

Set Up:

Install the CV joints on the set up axle. It is easier if you leave the boots off. It is even better if the CV

joints do not have any grease in them. You need to be able to see where the CV center is in its lateral travel.

Full Droop Measurement:

With the CV center, centered in its lateral travel, adjust the length of the axle so that the CV joints will just

bolt up to the flanges. You do not want the CV joint to extend to the point where the CV joints run out of

their lateral travel. This will break the CV cages.

Straight Across Measurement:

Check to see that the axle is not so log that the ends of the axle contact the insides of the CV flanges when

the axle is pushed to the end of its lateral travel in both directions. If the axle length is set accurately during

the full droop measurement, the axle length will most likely OK here.

Check The Other Side:

It is important to check the axle length on the other side. Many times, the lengths are different from side to
side.

Ordering:
The most accurate way to call out the axle length is from clip to clip. Remove the axle from the car.
Measure from clip to clip or from outside of star to outside of star. Add ¼” to this measurement. This is
your clip-to-clip length on the new axles. Axle lengths in our catalog are over all lengths. Add the
following amounts to get over all lengths. Some out board hub assemblies require half dome or full dome
ends.
To get over all length for axles with flat ends:
Add 5/16” for VW 33 tooth axles.
Add 5/16” for Porsche 930 axles.
Add 5/16” for Porsche 934 axles.
Axles with ½ dome ends, add 5/16” for each dome end.
Axles with full dome ends, add ½” for each dome end.

Ah, yes, thats true: if your using two different splines (VW one side, porsche the other), then a custom axle shaft is neccesary.

IIRC: if I recall correctly ;)