Land Rover front axle housing work

When I did the rebuild of my 109 I took one of my front axle housings and had it galvanized along with the frame, intending on putting it in my build.

I never got around to it, until now, though it is not in yet it is ready, finally.

Setting about to clean off the excess zinc using a propane torch I started on the flanges, heating and melting and wiping with a wet rag or blowing with my compressor. Finally drilling the holes to clean them and using a fine flat file on the mating surfaces.

Next came the special bolts which hold in the diff. These were heated until the zinc melted and then blown off which removed a fair amount of the zinc. Then trying heat and a wire wheel on a cordless drill. Neither method would get the last 3/8" of threads next to the housing clean.

What to do?

Oh heat up the zinc and unscrew the bolt.........................So I cut the safety wire on one bolt heated it up and began to work it out. Then the head broke off, leaving the threaded portion still in the hole. No problem, vise grips got it out now to find a replacement. What size are they?

The parts catalogue just says "special bolt".  My thread gauge showed 20tpi. About a week online and I got the size from the Series 2 club forum members, 3/8" x 20, However no one had a spare bolt. I did put out a call for taps and dies in this size as they are not common in the US. I also asked for the size and a tap for the axle housing drain plug. Again the S2 forum came through.

The drain plug;

The drain plug is 1-1/8" x 16tpi. Something was wrong with mine none of my plugs would screw in more than 1/8th of a turn. I needed a tap........they are not cheap or available in the US, but I found a Chinese supplier for $30 shipped online and I bought 1. https://www.ebay.com/itm/233330955793

Two S2 forum members, Winchman and Glenanderson sent me 3/8 x 20 taps and die and with then I was able to chase the special bolts and the 1 bolt hole. I found the special bolt I needed at PABlanchards (long one #1564)where I also bought a dozen nuts(#2513220) for them.

The replaced special bolt;

Running the die over the in situ bolts was a pain in the ass. because the die was round and not hex I had to use my die holder, but with it's 2 long arms I had to reset the die about 6 times each revolution. It took about an hour to do the first 4 bolts..............I needed something faster.
     What I came up with was that since I wasn't cutting new threads I could drive the die with some stiff rid in the clearing holes. So I found some rod and bent it in a U and used a cresent wrench to drive the die and chase the zinc out.

I did the next 5 bolts in 15 min.

Once that was done, I put in the new special bolt (long one-#1564) and safety wired the head to the rest of the bolts.

The new nuts were placed to protect the threads and for safekeeping.

Now I waited for the tap to come from China. When it finally arrived I went out between the rainstorms and ran the tap thru the hole.

It went in easy enough meaning I had the size and thread count right, then it hung up meaning I found the pinch point.

So using a cresent (adjustable) wrench I worked the tap around and thru the bad part and chasing out the excess zinc.

The plug threaded in easily by hand and pulled up tight with a wrench!  WOOT! WOOT!

I already had a 1/8 BSP tap for the axle breather and a 1/2 BSP for the fill plug. With these done and the  axle end seals(#244150) in place it is now ready for me to build up and install in the 109. That will be a day or 2 job next year after the Wet ends.