I was under my car last night preparing to change out the old style adjustable rear radius rods for the new 1926 flanged style and noticed on the rear wheel of the driver's side about 1/4" of the webbed brake lining was showing between the brake drum and the backing plate. There is nothing showing on the passenger side as the brake drum is tight against the backing plate as it should be, totally covering the brake lining. I haven't had a chance to investigate it yet, but what would cause the brake drum to be 1/4" away from the backing plate causing the webbed brake lining to show? I suppose the first thing I should do is to jack up the wheel, remove the hubcap and see if I can tighten the wheel nut in order to push the brake drum tight against the backing plate. If that is not it, what else could it be? Jim Patrick
PS. Upper picture shows the driver's side brake drum with exposed lining and the lower picture shows the right 1926 flanged rear radius rod and the left pre-1926 adjustable rear radius rod.
Hey Jim, has the car driven any differently? Usually when brake drum isn't looking right it's a clue that the axle has some play . . . which is a clue that it needs new thrust washers in the rear end. But from what I recall I'm pretty sure you've already done that?
I'd jack up that wheel and see if you can move the wheel in and out at all. After that, check and make sure you have a cotter pin in the axle nut. I've done that before, installed hub cap without cotter pin, scared me to death when I took it off and found it. Assuming you have no axle end play, before tightening anything up I'd take the wheel off and inspect the axle and key and the wheel hub, then check the hub nuts and make sure they haven't moved, lastly if all of that is ok I'd see where it goes when you put everything back together and tighten it up.
Seth. No it drives and handles as fine as it always has. To be honest, I'm not sure if I installed new thrust washers in 1971, which was the last time I worked inside the rear end. I do recall installing new leather seals, and new roller bearings and bearing liners (which I removed using a special tubular tube type puller with a spring loaded button, for the purpose). At 16 years of age and having only the Ford Bulletins Essentials and the Model T Service Manual as a guide, I don't remember being aware that the old thrust washers posed a hazard and if they looked good I doubt if I replaced them, since money (or the lack thereof) was always a problem during the restoration. Were the new thrust washers even available back then? Jim Patrick
That looks like a lot for a thrust washer failure. Probably more like an axle backing out of a spider driven gear on the inboard end of the axle...
Ooooohhhhh. Sounds serious. I would have never discovered this had I not needed to go under there to replace the rear radius rods. Everyone should do an overall (and underall) inspection of their Model T's whether they need to or not, so as to discover unexpected things like this.
Is that spider gear pressed onto the axle end? What would cause it to back out? What is the best way to repair that if it is backing out? Guess I won't be driving Miss Daisy until this is resolved and repaired. I'll keep you posted. Jim Patrick
Hey Jim, yeah, you need to get the rear end out from under the car and do a full inspection and potentially a rebuild.
I don't usually buy anything from Mac's, but their website has some great exploded diagrams. Here's the differential:
If it's really the thrust washers, the whole differential assembly will move inside the rear end housings. If it's just the axle on the spider gear (T2520B) then that's pretty easy to rebuild. Just FYI, Snyder's has brand new axles and they are GREAT. Mine were both worn so badly that I just had to get new ones. Also, highly recommend the new roller bearing units, they are very easy, really seal the rear end up really well, and are very smooth. Also, just know that if you're in there and re-building the rear end, you basically have to rebuild the drive shaft at the same time. HIGHLY recommend the Chaffin book and the Fun Projects Pinion bearing kit. Made it easy-peasy for me.
Check the end play in the axle, you could have a failed babbitt thrust plate. Its not likely the axle gear fitup is causing the situation. Are you sure this is something new and not something that's been there all along? Is the axle nut tight and hub fit correct?
May be Ted, but if he hasn't rebuilt the rear since the 70's, and wasn't sure then that he got the babbitt out, I'd say it's time for a tear down anyway. May end up being able to put the whole thing back together without messing with anything, but it's at least worth doing.
Ted, I'll check the nut tonight. Hopefully it is just a loose nut and tightening it will push the brake drum against the backing plate. If it is not the nut, I will need to do a complete dismantlement of the rear end. Jim Patrick
That axle gear may have been replaced in the 70s, and is much like the triple gear pins. In and out causes wear, and if the axle or the gears were changed for what ever reason and not sized perfectly, it could have slid off 1/4" Im not sure but the press on fit is probably -.002-.003". They are supposed to be pretty dang tight.
If yer really lucky the nut came loose, but that loose means losing a wheel in short order...
Good, but scary news. When I jacked the rear end and let off the emergency brake, the rear passenger side wheel wobbled like a drunk sailor. When I say wobble, I mean deflection of at least an inch to each side. When I looked at the brake drum there was about 1/2" of webbing showing instead of the 1/4" showing when the brake was engaged. I unscrewed the hub cap and the castle nut was backed off at least a 1/2" so that the threads could not even be seen through the castle nut gaps. The nut may have been hanging on by 4 to 6 threads, maybe less and the counter-clockwise turn of the left rear wheel could have easily spun the nut off completely in the next few turns if the wheel backed off enough for the axle key to fall out allowing the wheel to turn free of the tapered shaft. I pushed the wheel back onto the tapered axle against the backing plate and with a crescent wrench, screwed the nut tight and installed a cotter key, bent the tangs open and screwed on the hubcap. I then jacked up the other side and checked the nut. It was tight, but there was no cotter key in that side either so I installed one. Just to be on the safe side, everyone should check this on your car.
Luckily, it rained this last weekend, so I didn't go on my weekly drive like I normally do. A few more minutes of driving and this could have been a catastrophe. Somebody upstairs is looking out for me. The last time something like this happened, I ran out of gas and while waiting for my friend to bring me a gallon of gas discovered a layer of fine brown dust on the rim of the passenger side front wheel, which cause me to take a closer look and discover that the spokes were very lose and dry rotted. I subsequently re-spoked the wheel. Like I said. I think Miss Daisy has a Guardian Angel looking out for us. Jim Patrick
Thank you everyone who responded. Jim Patrick
Good one! Thank you Jim P for sharing all this. Yes, check such things! Even if you think you are sure it is as it should be. I bought a car one time that turned out to have no cotter pins in the front wheel bearing nuts. One of the nuts wasn't even a castle type. The seller had a good reputation and had driven the car a fair amount including a national club tour.
We all need reminders occasionally.
Drive carefully, and enjoy, W2
It's unlikely you got it tight enough with a crescent wrench. You need at least a socket and long 1/2 inch drive breaker bar. It really needs to be extreme tight , at least a 100 ft lbs.
To add to what Ted has just said, you do need 100 ft lbs, and after you drive it a few miles check it again to be sure it is still 100 ft lbs.
The bad news is that depending on how long it has been loose, the taper on the end of the axle and or inside the hub might be worn out. In which case, it will continue to wobble and perhaps get loose again.
Anyway, you found the problem and at least temporarily fixed it. Just keep a look at that wheel before every time you drive the car to see that it remains tight.
I did not use a torque wrench but I did get the nuts really tight with the crescent wrench until I was able to line up the cotter pin holes at one of the castle nut gaps. The drivers side cotter key hole is to the outside the castle nut gap so that the cotter key looped head barely catches between the two castle nut sides. The passenger side lines up between the castle nut sides as it is supposed to. What does this mean? I was afraid if I tightened the nut to line up the holes at the next gap, I might strip or split the nut. As a weightlifter who benches 275 lbs, when I tighten a nut to the point that I'm afraid I could do some damage, the fear is justified, but I will use my torque wrench tomorrow to see how tight I got it. If I reach 100 ft/lbs., but the cotter key hole has a ways to go before lining up with the next gap, should I continue on and force it to the next gap, or back it off to the prior gap where I had it? What is the absolute maximum torque these nuts can take? Do the tapered shaft shims work? Jim Patrick
100lbs will seat the taper. 1/2 of a pin notch wont break it, and if it does it was doomed for failure anyway. Like a wheel bearing nut, if you feel really insecure, seat the taper, then back the nut off a full turn and resume tightening it until you feel its at the threshold.
The other side that's on too deep has a worn taper. My drivers side has two .010" shims in it. Ive got about 500 miles on the hub install and I suppose its time to pull the wheels for a look see...
Back the nut off and install a thin washer under it.
That's exactly why I use a torque wrench. I don't know how large your crescent wrench is, but they usually have about a 10 to 12 " handle, and the jaw is so weak that 100 ft lbs would distort it and the wrench would slip on the nut. The torque wrench has about a 18 " handle and it feels like it would be about to twist something off when it is tightened to 100 ft lbs. So it is important to set the torque wrench to 100 and stop at that point. If it won't line up, either use a washer and try again if the nut is on beyond the slots, or file a little off the nut so that it lines up at 100 ft lbs. Too much is bad, but to little leads to it loosening over time because it rocks back and forth as you drive and causes wear which loosens it. It's also good to use a torque wrench when tightening the head, so it is a good investment.
Just installed RM brakes on my 16 touring. According to the instructions that came with the brakes the rear wheel castle nut should be "tightened to 'torque specs' 70 to 75 lbs".
I don't think torque wrenches were around at the time these were built though.
Jim..275 lbs on the bench!!! Is that with or without a chain-fall??
I normally drive 30 mph because any faster and the vibration and noise is so bad that it is almost unbearable. While I have driven my T since discovering the loose wheel and correcting it, I have not tried to go above 30. Do you suppose the loose wheel was the cause of such bad vibration and noise at 35? I'm anxious to see if I can now go faster than 35 without such bad vibration and noise, when I get home from work today. Jim Patrick
Before you drive very far on that hub that was loose,take it off and check the axle for a crack.I lost a wheel like that on a wire wheel hub. Not to much fun...
Is it possible there are 1/16" too long axles in this rear end?