I just pulled the rear end and noticed some interesting details. I have the following spares: a set of Unitrax (steel) half-shafts; a set of BTR (built by Central Florida Drive shaft) half-shafts; the oem half-shafts. I realize that comparing by weight alone is not totally accurate, however, the three different half-shafts are all pretty close in basic design. If anything, the Unitrax has larger (better) transition radii and larger fillets. Here are their weights:
1. OEM: 11.5 lbs
2. BTR (Florida Central): 13.5 lbs
3. Unitrax: 17.5 lbs
In general, the Unitrax shafts have much better workmanship and are 50% heavier than the oem shafts. I removed the oem shafts early on and have run the BTR shafts for several years. I am on my third set of the BTR half-shafts. To put this in the proper perspective, the car is close to 1000 ft lbs on the nitrous. I have not broke any half-shafts, however, I continually twist them in the splines. I always scribe a line on the two halves of the shaft, this allows you to see if they are twisted.
Twisting the shaft within the spline has several negative side affects:
A. It makes is hard or impossible to change the half-shaft or remove the rear-end.
B. The suspension will not work as expected, basically it changes the handling.
C. Keep in mind if you twist the half-shaft you probably have no way of knowing you have the problem. Depending on the shaft position when it twisted it can exert large forces against the knuckles/U-joints on the outsides of the rear-end. Those joints are meant to be strong and resist rotational forces, but, in this case you are applying either tensile or compressive forces in the direction of the rear end.
I just wonder if many of the posts regarding strange noises from the rear can be explained by a twisted half shaft. In this most recent case the drivers side was twisted, my scribe marks were no more then 1/16" apart and that shaft was locked. On the passenger side I was able to push it in, however, I have not had any luck pulling it back out - I will change them both.
I am removing 3.33's if anyone is interested. It is ring/pinion only. They have been drilled/threaded for the larger 7/16" bolts.
1. OEM: 11.5 lbs
2. BTR (Florida Central): 13.5 lbs
3. Unitrax: 17.5 lbs
In general, the Unitrax shafts have much better workmanship and are 50% heavier than the oem shafts. I removed the oem shafts early on and have run the BTR shafts for several years. I am on my third set of the BTR half-shafts. To put this in the proper perspective, the car is close to 1000 ft lbs on the nitrous. I have not broke any half-shafts, however, I continually twist them in the splines. I always scribe a line on the two halves of the shaft, this allows you to see if they are twisted.
Twisting the shaft within the spline has several negative side affects:
A. It makes is hard or impossible to change the half-shaft or remove the rear-end.
B. The suspension will not work as expected, basically it changes the handling.
C. Keep in mind if you twist the half-shaft you probably have no way of knowing you have the problem. Depending on the shaft position when it twisted it can exert large forces against the knuckles/U-joints on the outsides of the rear-end. Those joints are meant to be strong and resist rotational forces, but, in this case you are applying either tensile or compressive forces in the direction of the rear end.
I just wonder if many of the posts regarding strange noises from the rear can be explained by a twisted half shaft. In this most recent case the drivers side was twisted, my scribe marks were no more then 1/16" apart and that shaft was locked. On the passenger side I was able to push it in, however, I have not had any luck pulling it back out - I will change them both.
I am removing 3.33's if anyone is interested. It is ring/pinion only. They have been drilled/threaded for the larger 7/16" bolts.
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