How To: Restoration of Ford M8 armoured car US Ordnance number 7373

[Big D]

Hi Lynn,

Thanks for the reply. Not sure which backing plates you are referring to though?

Yes, the existing joints are scrap. I have NOS ones to replace them, so basically just need to get them off. I was just looking for a subtle way to do it!

I've been lubricating the tapered pins they are mounted on for the last couple of weeks. I've given the joints a wee bit of a 'tap' with a hammer but I guess a cold chisel and a bloody big hammer on the torque rod ends would be worth a go.

[Big D]

Hi all,

I’ve gradually been working away on this first axle. I think I probably picked the worst one to work on first so that is not a bad thing as this one has been a challenge from time to time. Hopefully the other two aren't as bad!

I got the other hub locking nut off. I had to use a grinder to cut a notch into the top of the nut and then I was able to use a cold chisel and a big hammer on the nut.

I eventually got the torque rod ends off. A 5 ton puller didn’t do the job and I’m not sure that a 10 ton would have done it either. All the puller does is pull the torque rod end outer sleeve over the top of the rubber surrounding the inner bush but it won’t actually pull the bush off the pin.

Cutting the outer part of the torque rod end seemed to be the best way to go. This leaves the inner bush stuck to the pin but I couldn’t see another option. I was able to remove some of these inner bushes by cutting a notch in the bush and then striking them with a cold chisel. Others were completely frozen onto the pin and had to be cut off with a cut off disc.

I was unable to remove the pinion yoke in situ so I went ahead and split the diff in the meantime. As you can see, there was a fair bit of junk in there. I figure the fact that one axle had been removed from the axle housing and the axle housing being left in the elements has allowed the dirt and moisture to get into the diff housing. Thus, the dirty mess inside when I opened it up.

I’ve done a strip down of the parts and given them an initial clean-up and I don’t think this diff shows signs of much use at all. There is a slight amount of pitting here and there from the moisture in the axle but overall a lot better than I expected when I first saw inside the diff housing.

I will replace the bearings and the axle housing inner oil seals and I’ll also take the diff parts to the blasters and explore the option of glass blasting to clean them up. I gather this is the preferred way to clean up these parts.

Once I have the pinion assembly out I’ll put it in the press and remove the yoke that way (hopefully). I’ll then replace the bearings on that assembly.

I’ve already dropped off the brake drums and backplates to the blasters and once I have the bearing cones out of the diff housings, I’ll get them off to the blasters as well for a clean up.

[Big D]

More pictures.

[Tim Bell]

Have you tried molasses bath to clean some of these parts rather than blasting them?

Tim

[Big D]

Hi Tim

No, I haven't tried anything as yet. I did read on another thread somewhere (can't recall where) where molasses was a good option for gears like these. I have been using molasses up until a few months ago on other things with pretty good results, I must say.

What do you think? Is that a better (it is certainly gentler) way to go?

[lynx42]

Originally Posted by Big D

Hi Tim

No, I haven't tried anything as yet. I did read on another thread somewhere (can't recall where) where molasses was a good option for gears like these. I have been using molasses up until a few months ago on other things with pretty good results, I must say.

What do you think? Is that a better (it is certainly gentler) way to go?

Darryl, when you are using molasses you have probably found that it won't work on anything that has had oil or grease on it. Even using degreaser before hand does not work. The enzymes in the mix won't touch anything slightly oily. Media blasting is the way to go with the housings as you can get the blast up inside the tube as well as that is probably pretty gunked up too.

Regards Rick.

[Big D]

Hi Lynn and Rick,

Thanks for the replies.

Lynn - yes, that is a good idea on the cones. I made an attempt to get one out by welding a bead around it but it proved stubborn anyway, so will wait until after the blasting before I have another go. I have kept what was left of the gaskets and will make sure I use the same thickness.

Rick - yes, I found exactly the same thing with molasses. As you say, despite a bit of cleaning, there is certainly some junk left in the housings, so I think the media blasting will be the way to go.


There are a couple of broken brake line cover bolts in the top of the axle housing which I’ll remove and then tidy up the holes. I’ll also need to free up the drain/filler plugs, as these are all frozen in place. Once I have them sorted, I’ll drop the axle housings and diff assembly off to the blasters.

[Lynn Eades]

Darryl, if you are going to blast them, leave the cups in, until you have them back.
Measure the old gasket thickness. It is likely the correct thickness to go back.