LaHo

I have a 1991 Dodge W350 with a Dana 70 rear differential, the spring pads and the spacer blocks next to them are worn to the point where the differential will not maintain driveline alignment. My 1st question is, are the pads and blocks made of cast steel or cast iron? If this question is not answerable it leads to the 2nd question, how to differentiate between cast steel and cast iron. I have done several searches on this website but was unable to find an answer. The truck is my primary driver, and I need to find a solution quickly, any and all help will be greatly appreciated.

Hillbilly66

IIRC the blocks are cast iron, but the pads are steel, you should be able to cut the pads off with a torch or grinder and weld new pads on. I've done that many times on other axles. But where you would find the correct replacement pads I'm not sure. But you should be able to order blocks from just about any parts store or a shop that does lift kits.

thrashingcows

There should be a locating pin on the bottom of the lift block. And a hole in the spring perch on the axle. Then there should be a hole in the top of the lift block, and then the center pin/bolt on the spring pack. Once all these are aligned, and the U-bolts are torqued down properly, there should be no movement.

I'm not sure how your drive line angle is changing? These are flat surfaces and there should be no way that the diff is rotating up or down.

LaHo

Thanks Hillbilly66. As the pads are cast steel I will rebuild them as there is just enough flat surface remaining to help me maintain the correct driveline alignment and just enough of the center pin hole that is undamaged that I will be able to repair them and maintain the axle tracking.
As far as the blocks go I will still try to get some replacement ones before attempting to rebuild them or make new ones.

LaHo

Thanks Thrashingcows. Unfortunately the u-bolts were not torqued down properly and the pad and block surfaces are gouged, fortunately there is a small amount of original surface remaining at the center pin area and on the pads to be able to repair and maintain alignment. I know it's going to be a tedious job, but I have more time than money.