MTFCA Forum

I've never heard of, nor seen a failure like this one !

Junior and his twin brother Junior were riding in the back seat. Juniors were big'ns.

I guess its a "quality escape"...

OUCH!! That was my concern when I saw That area on my axle oozing oil.

That can’t be a common issue in the T era! The break looks like the axle gear either came off the axle or it broke at that point inside the housing. Not sure.

It's an example of Canadian quality.

Wife & I hosted a tour a few years ago with a number of Canadian friends and at our airplane museum stop, one of the Canadian fellas noticed a puddle of lube under the rear axle - yep - broken just not quite complete through as the photo above - got him on the vulture wagon !

Used the axle to strap down on a trailer

One of our chapter members had that happen some years ago. It was caught before the axle shaft broke however. He welded it back together in place and has toured with it some 20 years since.

Man, That was one Heck of a pothole ! I'm going to sue the City !

Is this something the Canadian built Ts are notorious for?
It is of course a Canadian T, somewhere between late 1917 and 1920. "Late" 1917 because it has the three-light rear curtain (early 1917s still had the "tombstone" rear curtain?) and the offset windshield hinges changed to in mid 1917 (if Canadian Ts made that change about the same time USA cars did?).
The car can be no later than 1920 due to the 1920 Ontario license plate, and the Canadian car with still a two-man top and common straight windshield. Canadian built touring cars went to a slanted windshield and one-man top in 1920. The touring also has the earlier five panel rear tub making it 1920 or earlier.
Another Canadian detail is the fancy top cradle at the back of the body.
Some interesting details can be seen in this photo that I had not noticed elsewhere. The "two-man" top sockets clearly appear to be oval, however, zoomed in close there clearly are no "nesting" pins or sockets as the USA cars have. It does make sense however, with the clamping cradles to hold the sockets when the top is folded down, the "nesting cradles" used on USA cars are not needed. The oval sockets look rather bare without them.

About the broken axle. Clearly an interesting break. Both the axle itself and the housing appear to have broken in about the same place. There are a few scenarios that could cause that. Either the axle or the housing could possibly broken first, leading to the other's breaking. Most likely, the housing tube began to break first. Very likely a flaw in cutting or trimming the housing tube prior to being riveted into the housing "pumpkin", but could have been done as part of the cleanup after the riveting, left a small cut in a critical location near the end of where the tube is supported by the pumpkin casting. A combination of heavy use, vibration, or abuse, caused the small defect to become a major crack, which in turn would allow the housing to sag slightly. It would only need to sag slightly before the axle would be forced to flex with each and every revolution of the axle. Once that process began, the axle would break in a relatively short time. As the axle weakened, the weight on the housing would pressure the housing's crack to widen and weaken quickly. Probably, the axle broke apart first, with a sudden shift in forces on the housing to cause it to break merely moments after the axle let loose.
Other scenarios are possible. However, in some the scenarios, the axle itself would not actually break, the inner gear would need to come loose and be left inside the carrier. The wheel and axle are pulled out far enough that the end of an unbroken axle might not be visible. But if that were the case? What would cause what to break when? What would cause the housing tube to break when it did? In past discussions, it had been suggested the tube did not break, but the rivets let go and the tube might have slid out. Again, it would have had to leave the gear inside.

Again, I will ask out of curiosity. Is this a common failure among Canadian Ts?

Rivet failure. Where is the right axle shaft? Looks like it may have been pulled into the hollow tube when the right wheel and brake drum pulled loose from the differential housing. Looks like a fairly easy repair.

I live in Canada and have been in the Model T hobby for 50 years. I have Never seen this or any vintage scrap that resembled this.

Wayne, you missed an obvious Canadian detail. Ford in Canada produced cars for the RHD market in the British Empire. Hence there is a left hand side front door for cars used in RHD countries and a Canadian province or two. Canadian tourers had four doors.
Like a previous poster, I have never seen fossil evidence of such a failure in Australia in 60+ years of T motoring and restoration.

Allan from down under.

Nothing a little JB Weld can't fix !

Allan wrote: ↑

Sun Feb 11, 2024 12:29 am

Wayne, you missed an obvious Canadian detail. Ford in Canada produced cars for the RHD market in the British Empire. Hence there is a left hand side front door for cars used in RHD countries and a Canadian province or two. Canadian tourers had four doors.
Like a previous poster, I have never seen fossil evidence of such a failure in Australia in 60+ years of T motoring and restoration.

Allan from down under.

(Me laughing!) Thank you Allan B! I had intended to mention that door, the hinges clearly visible in the photo, but was rudely interrupted several times while typing, and eventually forgot to include it!

Allan B and Les S,
The reason of course I asked the question was that a couple earlier posts mentioned similar breaks in recent years. I had never heard of any similar breaks being commonplace on model Ts of any sort. Of course, there are always unusual exceptions to any general rule due to circumstances after manufacture was completed. Anything from collision damage to nasty repair work can cause future failures in many interesting ways.
I did once see a model T where the fellow restoring it thought the rivet heads looked bad where they were. So he ground them flat! Painted up really pretty and looked nice for a few years until vibration and stresses wallowed the rivets and holes slightly (they were already loose because the heads were gone!) and the remains of the headless rivets fell inside and the housing tube began to slide out as far as the axle and hub would allow it. Looked funny with the tube slid out about an 1/8 inch! Naturally, the entire rear end had to be rebuilt and about half replaced from the damage done.
Some people just do not understand how things work or how they are held together.

Shouldn't there be evidence of 600W oil?

Done by repeatedly bottoming out the rear spring, allowing the rear cross member to hammer the diff housing.

I think Wayne Sheldon's theory is the most valid. Only his explanation fits the fact that both the axle housing AND the Axle shaft failed at the same spot.
The axle would not have suddenly failed, without being constantly flexed at that point. Therefore, there must have been flexure at that point, to fatigue the axle into breaking, and the only logical explanation for that is that the housing cracked and was flexing the axle. The failure is matched to both the axle shaft and the housing, at the very same point, which supports that theory as being the most logical explanation.

A bearing sleeve installed without the dimple correctly in its hole can allow the axle to turn but will generate a great amount of heat. I had an axle break on the outer end due to that but not the housing. It could contribute to the problem.
Rich

Looks like sabotage to me.

Used too much when it was new.

No oil or grease on the ground or around the break seems to indicate it was run dry?

mbowen wrote: ↑

Mon Feb 12, 2024 1:46 pm

No oil or grease on the ground or around the break seems to indicate it was run dry?

Miles,

Think about how low the filler plug is on later T's. Given the amount of oil in the diff housing, I don't think the angle it's sitting at would dump out very much, if any. Plus, it probably didn't break right where it sits. There may be a gob of lube somewhere out of view.

IF (the big IF?) the housing tube cracked first? The rear end would have had to sag somewhat to stress the axle enough to cause a break. Doing so would have opened the crack slightly, certainly enough that the majority of the oil inside would have leaked out before the ultimate failure.

I am not absolutely convince the tube broke. Although I think that is the more likely scenario, I have a few times in recent past years zoomed in as close as the photo's definition would allow. I haven't been able to convince myself either way, whether the tube broke or the rivets failed and the tube pulled out. The problem for me is that it appears the tube may be long enough to have just pulled out (rivets failed?). However, from a structural engineering standpoint, I don't see a likely sequence of events to cause this result. Possible? Yes. Likely? Not so much. A couple years ago, I did attempt to triangulate the amount of tube showing, but the result was inconclusive. I may have to try that again?

Wayne Sheldon wrote: ↑

Mon Feb 12, 2024 8:44 pm

IF (the big IF?) the housing tube cracked first? The rear end would have had to sag somewhat to stress the axle enough to cause a break. Doing so would have opened the crack slightly, certainly enough that the majority of the oil inside would have leaked out before the ultimate failure.

I am not absolutely convince the tube broke. Although I think that is the more likely scenario, I have a few times in recent past years zoomed in as close as the photo's definition would allow. I haven't been able to convince myself either way, whether the tube broke or the rivets failed and the tube pulled out. The problem for me is that it appears the tube may be long enough to have just pulled out (rivets failed?). However, from a structural engineering standpoint, I don't see a likely sequence of events to cause this result. Possible? Yes. Likely? Not so much. A couple years ago, I did attempt to triangulate the amount of tube showing, but the result was inconclusive. I may have to try that again?

What on earth would cause the rivets to fail?

I found this photo in the Toronto Guardian Archives. Interesting, isn't it? Lots of further comments and speculation here: https://www.facebook.com/groups/Fordmod ... up_comment

Someone mechanic put new tires on all around and filled with plenty of air but they jacked it up by the rear differential and half sheared the rivets.

Jerry, That is part of the problem. In a past discussion it was argued that the tube had pulled out of the casting, But I can't reconcile that in what I can see. I did (a few years ago) try to triangulate the axle tubes from side to side to determine the length of tube remaining with the backing plate, and it did appear to be a bit too long to have broken outside the center casting. But the angles to work with had made it difficult, and I couldn't convince myself of a sufficient degree of accuracy. (I feel like I need to try again?)
For the rivets to fail that way, something would most likely have to have been done very badly. Rivets too small? (Unlikely.) Tube to casting fit too loose or too tight? (Possible?) If the tube was too tight? It could have only been pressed in halfway resulting in insufficient support and too much dependence upon only the rivets? But I think that is also unlikely. Is it possible that somehow nobody drilled the housings and installed the rivets? Could quality control have missed such an error? Unlikely, and even if they did, the way the entire rear end fits together, it would take some abusively heavy loads, or high speeds on very rough roads to overwork all the parts for the axle itself to give up and let the tube go.

I cannot dismiss entirely the possibility that the tube pulled out of the housing. However, I have yet to think through or read of a likely way that would happen. It would be nice to be able to examine the parts up close, determine exactly what did happen and how.
Part of the problem for me is that many years ago, I had a model T rear end that had been used under a trailer that had obviously been very heavily overloaded and abused a lot! Wooden blocks had been wired in between the spring and rear end housings to keep the it from being compressed too low. The thing had been overloaded so much that both housing tubes had been forced and beaten to bend more than one would expect to ever see short of collision damage. The abuse was severe, the damage was extreme, but nothing broke or came apart. The housing was bent badly enough, the thrust washers chewed to pieces, that the ring gear inside the sagging housing hit the outer side of the housing and ground itself through the casting nearly half way around the housing! (I still have that center and tube, I welded a shelf and cradle onto the outer end to hold welding torch and tools when I am using the torch, it is my "welder's butler".)
All that abuse, and all that damage, yet nothing actually broke or fell apart tells me that the model T rear end design and construction is pretty tough!

I am not sure why mechanical failures and bad engineering fascinate me so much. Part of it I know was that much of my work involved my safety being at the mercy of bad engineering and my life often depended upon things not breaking. We often had to deal with the aftermath of equipment failures, and in turn tried to prevent them from happening to us.