Willwood Rear Disc Brake Installation Question

[Needa68]

We're installing a Willwood Rear Disc Brake system on an 8 3/4 inch rear end. This kit replaces the old axel bearings with green bearings and does away with the old axel adjustment mechanism. The installation went perfectly on the driver side. The passenger side not so well. With both axels in place we are unable to get the caliber to mount. It lacks about 1/8 of an inch. The passenger side axel will not go in far enough to allow the caliber to mount. There is still plenty of room between the hub at the end of the axel and the Willwood mounting hardware for the shaft to move in the required distance. The bearing doesn't appear to be the problem because without it we have the same issue. It appears the axel is bottoming out or up against the other axel in the differential.

Before tearing the differential apart to determine if in fact what we believe is happening actually is we decided to ask for help here. Is it possible for the axel shafts to butt up in the differential? If so, would it hurt to remove some length from both shafts?

[John_Kunkel]

I've always advocated removing the thrust block from the center of the differential when using the Greens.

Are you using the snap-ring type Greens? I've heard some disagreement on the position of the snap ring, some say that if the snap ring bears against the axle housing, the same problem you're having occurs but if the snap ring bears against the outside of the backing plate the distance is correct.

Might be worth a call to Wilwood for clarification.

[Needa68]

Removing the thrust block sounds like a probable solution. I don't remember any snap rings with the "greens" but I didn't install them either. Will check into that tomorrow. Will also contact Willwood as you suggest! Thanks for the feedback!

[John_Kunkel]

The thrust block shouldn't cause the amount of over length you're experiencing unless they're aftermarket axles which are often a little long.

Green makes two style bearings, one has a snap ring and the other has a captive flange on the bearing, Wilwood specifies only one for each kit.

[Needa68]

The issue was the length of the axel. It could have been an after market axel because lots of parts on this car have been replaced. I don't know if it was or not because we didn't try to determine its origin. We took very little off the end of the shaft but after we did the Willwood brake assembly fit as it should.

Thanks for your assistance!