The thicker retention plates meant that our old bolts were too short. Besides, we were using general, grade-5 bolts from our local hardware store—not the right stuff. Currie suggested the grade-8 T-bolts (on the right, PN CE-2012, $1.50 each including the nut). They were long enough to accommodate the thicker plates, stronger, and we wouldn’t have to grind one side down to clear the axle tube.
Another probable culprit in regards to our leaks was our venting system. The housing was fitted with a 6-AN fitting and we had drilled and tapped a cap to accept an 1/8-pipe pop-valve. Currie felt this wasn’t allowing air to enter and escape the rear at a quick enough rate, this caused an increase in pressure within the housing under aggressive driving, which only made the leaks even worse. Their suggestion was the cap-style breather vent (PN CE-9028, $4.95) on the right. It will flow plenty of air, even under hard, heat generating, driving.
With the axle seal leaks addressed it was time to figure out why our center section always leaked. We found out our housing was warped and not close to flat. We’re sure it came to us in the right shape, but it must have warped a bit when we welded on the brackets for the three link system. This in turn kept the housing from sitting flush with the old center section. With our new aluminum case the problem would have been even worse. To fix this Currie removed the studs and used a large hammer to persuade the case back into shape. After working over the flange with a flat file we were back in business. The moral of this story is to check your housing and make sure it’s square before installing a center section, especially if you’ve welded on it.
Another spot for potential leaks is around the bolts holding the center section in place. On the old unit we had just used nuts and lock washers, but Currie feels this isn’t the best way to secure the third member. They recommend Nylock nuts, which will never loosen up, with aluminum crush washers to further guard against leaks. Currie sells the nuts, washers, and gasket in one convenient kit (PN CE-9007 $6.95).
Running the right fluid is also critical for keeping your rearend assembly working trouble free. Currie suggest a non-synthetic heavyweight 85/140 gear oil and they also advise that the gear be broken in by raising the rear on jackstands, running the car for 10 minutes, letting it cool for an hour, then take the car for a 10 minute cruise and let it cool again. After that you should be good to go.
The new aluminum centersection looks great, but more importantly it’s been installed the right way. The changes made to the axle seal parts and fixing other problems should pay large dividends down the road with better performance and leak-free operation.