MTFCA Forum

Tried to video the chattering that often happens at the last few feet of a complete stop. This didn’t happen when I was seating the new kevlar bands two years ago. It was gradual over a thousand miles. Also get chattering when starting on a hill. By the time it happens in braking the car is no longer in gear and the rpms are low.

https://m.youtube.com/watch?v=WTB5_dtb1 ... e=youtu.be

I'm thinking the two things aren't related as in it's not the brakes or the low band. U-joint or differential ?

I rebuilt the rear end when I went through the mechanicals but used the original u-joint and drive shaft. I didn’t replace the drive shaft bushing if that’s a possibility. But why would it start now and not be a problem right away?

Depends on what kind of bands you have. One of my cars has wood bands, and although they wear almost forever, the brake does chatter a little just before it comes to a stop. Also another possible problem if you are still in low gear at the time, is if your engine idles a bit rough at low speeds, it could cause a chatter. Also could be U joint of U joint bushing or 4th main as posted above.
Norm

My car idles beautifully at such a slow RPM you can count the individual cylinders. In the video I’m driving very slow in high gear and throttled down as far as I can.

The band linings are Kevlar. Never heard of them glazing but it feels like that. Most of my driving is sudden stops and going at 30 mph in city situations.

I have planned to pull one or two of the “quick change” bands to inspect this summer. Am putting together a couple of cork insert style bands to try as well.

I never even looked at the driveshaft bushing when I rebuilt the rear assembly. So, that has me thinking. At the least I should shoot some more lube in the bushing to see if there is a difference. Did use a fun projects rear drive shaft bearing assembly.

Mark, my 1912 chocolate van sees much city driving, and heavy stops too. It has chattered on its keval bands as it is almost stopped for as long as I can remember. I just drive around it. Ease up on the brake when almost stopped., engage first gear if needed, re-apply brake right at the end. Not a hard routine with time to execute. All the way sudden stops which are unavoidable means I have to bear the chatter at the end. Again, I can do that much easier than chase a possible 'cure'.

Allan from down under.

Allan, thanks so much for confirming that it could possibly be a band issue and a Kevlar band issue at that. Chattering in the old days was almost always considered a band problem.

Yes, I drive my T to the museum where I work every day so I’ve also learned how to subdue the effect somewhat. A hundred feet from the stop I half pedal the clutch to neutral, throttle down and retard the spark ....then I press the brake down all the way a few times and let up just before the car comes to a complete stop and coast to a stop. But I would sure like not to have to do all that. When I install the cork embedded band linings I’ll post the results. Fingers crossed.

I had a 27 roadster that did exactly that. Joe Bell suggested it was possibly loose rivets in the tailshaft. Sure enough, that took care of it. About a 4 hour job for him to fix ,but he’s superhuman !

Tell me more ... but first let me know what you mean by “tailshaft” and where is it riveted?

Mark, my symptoms were exactly what you describe. If you take off your inspection cover, you can see the end of the tailshaft . You have to put some pressure on it from different angles and look VERY closely at the rivets. If you can see a little squish of oil, your rvits are lose. The only way to fix it is take it out and replace or remove and re-rivet them.

I have AC brakes and have been trying to dial in the balance between the ACs and the trans brake. My latest adjustment to the trans brake has resulted in the same chattering that Mark is experiencing. Prior to the latest adjustment it was braking primarily with the AC and taking a while to stop. I wonder if in my case that perhaps a tightening further of the trans brake would address the chatter...thoughts?

I have the same issue with my '14. Kevlar lining, non-demountable bands. No chatter until the last few feet, just before coming to a complete stop. I tightened up the brake band and it definitely helped, although it's still there. The issue started last year, after 10 years of chatter-free driving. I will check the plate rivets next. If necessary, I have a NOS drive plate assembly to replace it with.

I’ll check the plate for loose rivets ... but fingers crossed it’s not that. Removing the engine for that would be such a pain given my limited work space.

I agree , a real pain. If that is the problem, it’ll only get worse and wear everything else out, too. Joe made it look easy but would have taken me a month of Sunday’s !

I add a 1/2 quart of automatic trans fluid to my oil. No chatter.

My coupelet's brake chatters also, was a little concerned but I've gotten over it. I'm running kevlar linings.

I’d have no problem with using a little ATF in a Model T transmission, but I’d NEVER suggest using it in the engine...

How can you use ATF in the transmission without also in the engine? Only possible if you have an auxiliary transmission!
Norm

Thas' a joke, I say thas' a joke son. (I hope).

I opened the transmission cover to tighten the brake band one turn. While I was there I tried to apply pressure on the shaft to see if any of the rivets on the shaft plate moved. For the life of me though I couldn’t find anywhere that one could apply pressure to test that. But I did knock around in there and it is tight as a tic.

The one thing I did notice is that the brake drum is shinier than the other two. Not blue or discolored .. just smoother and shinier.

Mark Osterman wrote: ↑

Sat Jun 29, 2019 12:16 pm

. . . brake drum is shinier than the other two. Not blue or discolored .. just smoother and shinier.

The accepted wisdom in driving technique is to avoid "feathering" the low and reverse bands; get right on 'em and lock them up quickly as is practical. I'd reckon no one advises doing that while braking; ergo, slippage will occur with each use of the brake, resulting in a high polish on the brake drum.

The only way I can think of to see if the rivets are loose without removing the transmission would be to have someone put on the foot brake hard with the clutch in neutral and someone else rock the car back and forth while you look in with a good flashlight. This would take at least 2 people and better 3. Problem with trying to pry up and down is the 4th main will keep the shaft from moving up and down.
Norm

Try pumping the brakes to get more oil between the lining and the drum and also consider tightening up on the adjustment a bit

Rich,

The theory is to push firmly and then let up completely and push firmly again with Kevlar to get more oil in between. I always brake on compression until the last hundred feet ... then do the technique above with the throttle completely retarded and the car free wheeling.

My sense is that the Kevlar is glazed, but am told this can’t happen given the material. Glazed linings are the number one cause of chattering based on all the period trouble shooting guides. Another cause is the angle of the cast band end, fixed by inserting a washer.

Today I tightened the brake band by one turn which made no difference. As I mentioned before I had no problem while I was seating the band linings. I think it’s lining related and am anxious to pull the band and inspect it. Also to try another material or cork inserts.

Mark, in your initial post you said that you get chattering in low going up a hill also. Is it the same violent shaking you get while braking? You also said you replaced the rear bearing assembly with one from F/P, did you pin the driveshaft/U-joint along with the locking ring supplied by F/P?

Yes, on occasion I do get some chatter when I transition from low into high gear. Not all the time. Also, in my video that I first posted I made sure the chattering would happen. There are procedures I use that reduces it, but I wanted others to hear it. Makes the whole car vibrate.

Yes, I installed the Fun Projects driveshaft bearing assembly as described in their instructions. This is my second T with that kit and I really like them. Yes, I did install the typical U-joint pin. Like I said I did not even check the upper drive shaft to U-joint bushing. But I still have a sense it’s band related.

Just for the record and my curiosity Mark.
And NOT to poke the hornets nest...

What type of oil are you running ?

WHAT ... I’m supposed to have oil in there?!

LOL ... well this month I have Pennzoil 5w 20 in there. Other times I use 10w 30. Generally what’s on sale and I change it about every six weeks. I drive the car nearly every day ... about 100 miles a week or more.

Mark

you should really rethink the present choice of oil in your car

When oil ceases to be a hydrodynamic film, it's simply boundary lubricant. Nearly all tailshafts have more runout than they should have and if the lubricant cannot sufficiently maintain it's wedge, you're going to beat out the 4th main and this can cause trouble like you're experiencing.

Ok .... no problem, easy to do. I have used 10w30 for years in my other T and in this one. I tried the current oil weight based on what people posted on the forum. What weight or type oil would you suggest?

With all due respect, the amount of car rattling vibrations in your vid will never be solved by changing the viscosity of your oil, there is definitely a mechanical problem, especially since you said you get it at other times other than just braking. just my 2 cents of course.

Well, chattering has been around since the first model T and now that I’ve posted the video it seems that others have had the same effect on their cars. I can’t imagine it’s the oil viscosity either but have heard about adding ATF. Like I said, nearly all of the period literature suggests something about the bands as the problem not drivetrain, clutch or transmission. But I’d really like to hear something definitive from someone who has discovered the mechanical cause and figured out a solution.

John

I agree with you. That is because I did not suggest that changing viscosity will fix the problem. I stated that when oil loses it's ability to maintain a hydrodynamic film, wear will occur rapidly.

Mark

Kevlar is not indestructible, and like any woven material can trap contaminants which will burn/carburize. Your thoughts that the band may be glazed may not be entirely off the mark, particularly given your description of the brake drum. This is one of several possible contributors to your malady and you will unfortunately have to work through it. I have read accounts of Kevlar being removed and literally scraped to remove the crud and then successfully reinstalled. I have neither seen nor experienced this and only contribute it as hear-say.

My father's depot hack had "bonded" linings from the '70's. Truly an abomination. They acted and sounded exactly like yours until the day they were mercifully removed and replaced with Kevlar.

I too doubt the oil is the cause of the chatter.
I agree that 5W-20 is not recommended, especially in the summer. I recall Steve J attributed his rod bearing failure on 5W-20.
When hot, that stuff has the viscosity of kerosene !

Take pictures when you decide what to do.

Listening to the video seems to me driveline looseness, unlike typical band chatter. That is normally associated with low pedal engagement with worn lining on the low band. But can happen with loose adj. or poor worn lining on the brake band.

Assuming your linings are in good shape:
You posted it happens 'starting on a hill', I assume with low gear, that puts the planetary gears in play, without the clutch engaged. As long as the low pedal in fully engaged and good lining.

Your video showed you moving out of low pedal, ( no real chatter then), and coasting to a stop with pedal halfway, no clutch engaged.

Then a lot of rattling when brake applied, noise to me would be trans. Worn bushings in triple gears, or as mentioned tailshaft that takes all the go and stop to the driveline has loose rivets, or maybe other pieces of the trans. Or, loose ball joint, and loose U-joint can contribute to the drive line separation gaps, that is happening when you stop, making that clucking, clunking sounds.

Hmm ... well, the transmission was all rebuilt, all new bushings etc. and everything that rotates balanced. The U-joint was good and tight, the forth bearing new and reamed for the shaft. The only thing overlooked was the upper drive shaft bushing. What is the sequence of trouble shooting I should do short of removing my engine, which would be a very difficult thing for me to fo at this point given where I live and the limited space I have.

My Kevlar bands were great until my cracked block let some coolant in the oil. I think it was the antifreeze that caused my bands to chatter. It’s been several oil changes now and they are better.