8050 rear axle wedge hub removal

Been messing with this wedge system today ...



The 4 clamping bolts seemed to be 3/4 - 10, came out easy. Removing them revealed the fine threads for the pusher bolts. Looked like 7/8-14 and I didn't have a tap. Wire brushed them and rinsed with PB Blaster a lot, then anti-seize. The 7/8-14 pusher bolts I purchased seemed to turn really hard, so I kept cleaning the threads till it was somewhat better. They never would screw in without great difficulty so I wonder if those threads are metric or oddball tpi ? Anybody know ? I'd like to get the correct tap and pusher bolt.

My service manual doesn't address these wedge clamps. I read somewhere else to work on the wedge opposite the keyway first as this is the side that applies the clamping pressure to the joint. That side isn't flush so I guess I will work on it first.

I'm uncomfortable striking the end of the axle but is that what is required to break loose the wedges ?

Thanks.



Edited by smitty78 - 17 Sep 2016 at 8:51pm

7/8-12

I've had a few older mechanics tell me that these holes got damaged often.  When that happened they re-tapped them 1"-8 tpi.   I have run across 1 wedge that had been converted that way.  That would be a possible last ditch measure if your holes are cross threaded and then strip out.  I've never looked for 1 but maybe they make a 7/8-12 heli-coil insert to repair the damaged threads back to OEM. 

If you don't use the regular pusher bolts, you will destroy the threads in wheel center.   MACK

The holes in the wedges are threaded 7/8-12.  The bolts that normally hold the wedge in place are 3/4-10TPI and so they pass through the larger wedge holes without interference. By memory the pilot bolts about 6-8"" long.  One end is hex head.  The body is two different diameters.  The first couple of inches is about 1/2" to 5/8" in diameter and has no threads on it.  The balance is threaded 7/8-12.   As you screw the threaded section into the wedge, the smaller diameter section passes through the threaded part of the hub hole ( without touching those threads ) and bottoms out against the bottom of these blind holes.  As you continue to turn the pilot bolt, it puts outward pressure against the wedge and pushes it out of the tapered section of the wheel hub.  In my previous post I mentioned increasing the thread in the wedge to 1"-8 TPI.  In that case they just took a grade 8 bolt and reduced the diameter of the first few inches of the bolt in a lathe to match an Allis pilot bolt.   I'm not a fan of this last ditch effort but it does work if you have stripped the wedge holes.  If you need a picture of the Allis OEM pilot bolts, I'll see if I can figure out how to do that.