Rear Differential Pt. 3

Nov 30, 2020

Well, some new parts were ordered (to replace the ones I bungled / mangled in the vise) through Bearmach in the UK. Quick turnaround, they have a lot of stuff, but the shipping will of course be the killer, here. They air freight small stuff via DHL which is as expensive as you might imagine it is. 

I bought a pinion flange to replace the one I mangled, and it is a part that's made in India. The holes for the propshaft bolts are not neatly in the middle of the flange surface, as I would have expected. Looking at my old parts though, they don't seem to be really lined up, either. I guess 'farming equipment' like an old Land Rover is sort of expected to shudder and vibrate. :/

I picked up some other parts, too. The lock tabs for the oil seal retaining piece, some copper washers for the drain and fill plugs, and while I was at it I picked up a new driving flange as well, on the assumption that mine are worn. I'll post more about these in the future. 

Anyway, on to the photos. 

As you can see, the whole thing sort-of-halfway bolts together as it should, though nothing is tightened down. This is good news. 

Despite that, I'm not 100% confident in the job I did, to be quite honest. I am aware that the Haynes manual says, 'You can't expect to really do much as a home mechanic in here' when it references the differentials. So, I essentially decided just to clean up and repaint the unit, replacing any consumables that had deteriorated. 

Contributing to my lack of confidence is the fact that one of the shims for the bearing preload had worn extremely thin -- to the point where it was fragmenting -- and I have not replaced it, not knowing what thickness the original shim was. Also, the crownwheel / pinion backlash is, I think, too great. 

I'm not sure I have the 'cage' locknuts on the differential carrier in the right place. I think you need marking compound to check the alignment of the crownwheel and pinion. 

There are other elements I'm not thrilled about: 

Pro tip, when you paint new parts you shouldn't use cheap auto body primer (like I did) and should instead pay extra for the good etch primer. I think I used a Duplicolor primer here. Admittedly, I'd only ever intended to get something on there because I had to clean the shipping grease off and didn't want to leave it bare. I figured I would just topcoat with chassis black later. 

It doesn't help, I think, that I've been painting in cold weather and using a space heater + cardboard 'hut' arrangement to keep the parts warm enough to cure. Obviously, not an ideal environment. 

But, I *did* manage to drift the mud shield on to the brand new input pinion without marring it this time: 

So, you know, victory!

But either I think I've ordered the wrong 'gasket' (it seems to be brass?) for the oil seal retainer as you can see:

Again, not giving me tons of confidence that I'm doing this rebuild thing correctly. I've consoled myself with the thought that this is part of the process (right?) and one just has to accept that there are going to be f*ckups and misses along the way. 

Maybe I should reread Zen and the Art of Motorcycle Maintenance. 

I did accomplish something else this past week though, managing to "make" some aluminum jaws for my vise. 

Tool of the Week!

A vise is a shop essential. I probably overbought mine -- it's a 5.5" unit -- but I figured buy once, cry once. I suppose if I were to to it again, I'd get a smaller unit, maybe 4" is all you really need, and I'd mount it to the mobile Uline shop cart I also bought so that when you're grinding or sanding or wire wheeling something you're not throwing crap all over your work area. You can see the cart just in the background of the photo above. 

Still, I do other things besides Land Rover stuff so having the vise mounted to the workbench seems like it'll do.

When you get a vise, you will need to do something about the tool steel jaws they give you. Pretty much anything you put in there will be marred. I bought an expensive set of rubber vise jaws, but those move around too much when you need to hammer on something (like an input flange.) So I went to Metal Mart in Langley. They aren't kidding when they say, "no job too small." A couple of pieces of 1/2" x 3/4" and now I have some vise jaws. Good service at Metal Mart. 

Anyway, I went into this job thinking, "How hard can it be?" Just drill some holes. Easy. 

Having now completed it, I learnt that apparently I can't drill straight . Or measure well. This should, I think, put me in the same shoes as many Leyland employees from the 1970s...

Also, I had to buy a bigger drill bit because the screw heads were larger than the largest size bit I have. I am beginning to wonder if I am just buying extra stuff I don't need. Aren't you supposed to be able to fix old Land Rovers in the jungle with a rock and a crescent wrench?