MTFCA Forum

I went to start reassembling my axle for a test fit and realize I failed to measure one thing: the outer collar on the left half differential shell, which keeps the steel washer and thrust washer centered, is badly worn. It's cone shaped where the old babbitt washer was, at least 1/16 if not 1/8 under. It's fine where the steel washer is. I imagine it's not OK to have my nice new bronze washer slipping around without a good center, so my question: I have a good local machine shop. Does it seem reasonable to have them machine away part of the collar and slip an nice steel collar over it? I haven't seen a lot of nice differential cases offered for sale so I'm tempted to try to salvage this one, unless there's a good reason not to. I do have a "spare" differential case but it has several serious flaws that caused me to put it aside when I started this project. My replacement was OK in all the places the old one wasn't, but I failed to check this collar.

I had a similar issue and I bought a repaired/rebuilt differential case half from Bob Bergstadt, all repaired and ready to go. Everything fit right back to factory specs. He lists them here on the forum from time to time and on Ebay or you can call him at Bob's Antique Auto Parts bobsantiqueautoparts.com

I have them in stock --815-633-7244
Bob

Quick follow up to finish this story, in case it is useful to others:

I found that McMaster Carr will make a custom bushing from Rockwell C61 steel for $43. You give them ID and OD, as well as height, and they make to the nearest 0.001". The only catch is you have to wait 3 weeks. While Bob had a nice differential case in stock there was the challenge of repairing instead of replacing.

I turned the old differential on a lathe to make a uniform collar, measured it with dial calipers and used that for ID, with the Ford spec OD and height. As you see the old collar is a little short too, but that leaves me some room for a couple of welds to tack it in place. It pressed on pretty tight, but I'm not sure what sort of forces and vibrations are present at the differential so I will tack it in place. Can't wait to finish this assembly. It's been spread all over my garage for a month.

The differential part is cast. Not sure if its gray iron or ductile iron. You might make a mess if you try welding on it. If its gray iron it will be like welding on a rock. If its ductile, results may be slightly better.

Adam, there are (or at least were ten years ago) several arc welding rod suppliers that make several rod types for welding on various cast irons and welding cast iron to steel. They can be a bit spendy, but work great using the proper techniques. Some leave a machinable deposit, some don't. I have repaired many castings by welding to a piece of steel. Most all suppliers have handbooks with all of the recommendations and procedures. Dave

D Stroud, You are correct. HOWEVER, the vast majority of hobbyists as well as some professionals are unlikely to have the right equipment, supplies, or skills. A well equipped, experienced welder can weld just about anything given the right circumstances. Some people can make a mould and cast and machine these parts themselves too...

Thanks for the warning, Adam. I have access to a skilled welder-- I'll pass along your warning. I have a spare wrecked casting to practice on if he has the right equipment.

I probably should trust the press fit anyway, but this is a learning process so I'll see what I can learn about welding to castings.

Arthur B, You have it perfectly figured out. Having your welder practice on a junk casting is an excellent way to proceed.

Why not use Loctite sleeve retainer?

Richard

I was wondering the same thing, but too late now.