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

[Lynn Eades]

Darryl, Drop the pinion and bearing carrier from the housing. Borrow a bearing separator to better support the flange and go to a bigger press.

[Big D]

Hi Lynn

Thanks for the reply. If you mean pulling the whole pinion assembly from the housing, yoke and all, then I have tried that as well. I would have thought that I could 'tap' it out from inside the axle housing but I got no movement on the pinion assembly that way either. I guess I am dealing with two bearing assemblies that are themselves very tight in the housing.

Any bright ideas for doing this?

[T Creighton]

Hi Darryl,
Impressive project you have there.
Are those diffs the same or similar to the truck ones?
If they are I have a spare flange you can have if you have to cut yours although they shouldn't be that hard to get off.
My book says just tap the flange off with a soft hammer and then use a puller to extract the pinion oil seal retainer housing complete with pinion shaft and bearings.
Regards, Terry

[Big D]

Hi Terry

Thanks for the reply and the offer. Yes, more than enough work in this project to keep me busy!

The axles should be the same as Ford truck diffs. I've attached a few pictures from the manual.

I'm thinking that a new approach as per Lynn's suggestion might be in order, but I'm not sure how to best tackle it. Considering I can't take the yoke off first, what is the best way of trying to get access to the sleeve and the bearing cups? With the yoke still attached, there is only about 5mm clearance between the oil seal retainer and the pinion gear sleeve.

Could I somehow ease that pinion sleeve out of the housing?

[T Creighton]

Hi Darryl,
It is different to the truck ones in that the yoke and shaft are tapered and keyed, not splined. My flange would not definitely not suit.
The taper should be easier to move than rusted-in splines although the key and keyway are probably the problem.
Can you get a drift along the key way to give the key a whack.
Do you have a Picavant hydraulic puller? That and more heat than a propane torch.
Cheers, Terry

[Lynn Eades]

Darryl the pinion sleeve is a snug fit in the housing and they usually require the housing to be heated to put the sleeve in. It may take a bit to get it out, but if you take the sleeve out of the housing, it will be easier to deal with. You diff is a Timken (or Ford) style, so there may be a bit of useful info in Ford manuals of the era.
Do you have all the service info for the M8 axles, preload etc?

[Big D]

Hi Terry and Lynn,

Thanks for the replies.

Terry - there is not a lot of room to get to the key, so that may not be an option. I have various pullers here but not the model you mentioned. As you say, there is no comparison between oxy and propane.

Lynn - yes, I have all the manuals and information to set it all up again. The heating required may be a problem with what I have here.

I spoke to my local mechanic this morning and he will take a look at the problem. I figure he will have the tools to both heat things up and remove them, much better than I can within a reasonable time frame. It may be a few dollars well spent I feel.

Will keep you posted.

[John Mackie]

Darryl over the years i have had to remove many pinion yokes. as yet i have not had to go past the tool attatched to the yoke with 2 bolts.
if you have to resort to heat you have to use a lot of heat and get the yoke hot quickly before the heat conducts to the pinion. a hit with a heavy hammer on the puller bolt IF IT IS YOURS may help.
best of luck with the great project.
I WOULD REMOVE THE BALL BEARING AS IT MAY SHATTER AND FLY.
John.