This morning our club was going to have a tour of El Cajon and Lakeside, Ca. I live in Alpine about 15 miles away, and so as usual drove the T from home. We got about 6 miles and it was running very well. We made a right turn and all of a sudden, there was a big Bang and it skidded to a stop. It won't go into neutral so we waited right where it stopped. We had about 20 cars stop to see if we needed help. Meanwhile, we had called our son to bring the truck, trailer, and floor jack. He arrived in about 1/2 hour and we had to jack up one rear wheel in order to get it to move. We winched it onto the trailer which took about 1/2 hour and took it home. Parked the truck and trailer, and took another of our T's and joined the tour. we had a good tour and visited a collection of about 10 1950's Chevrolets completely restored, and about 30 old gas pumps and signs from gas stations. Then went to lunch. After returning home, we unloaded the T from the trailer and got it into the garage.

Well, now I have something to do. I think something in the transmission is broken, because the pedals seem very tight and before they went almost to the floor. The engine won't turn even with the crank nor the neutral work. Anyway, I will take it apart some other day. I'm tired!

This is the good thing about having more than one Model T. A breakdown doesn't ruin the whole day.
Norm

Sorry for the misfortune, Which T? Looking forward (with some regret) to hearing more about it.
Dex

Sorry to hear about the problem. As I understand it, it's just a theory anyway. In any case, glad your whole day wasn't ruined.

The 22 Runabout. I had a premonition that something might not be just right. I thought the battery was low and it seemed to hand crank a bit hard. It also tended to creep forward when in neutral. It seemed to be running great up until that happened. I haven't looked into it, but am quite sure the problem is in the transmission, because the pedals seem to be different. That is It is hard to push in the low pedal or the brake. I think maybe one or more drums are broken, or possibly the triple gears? Will know more when I get into it. I'm tired.
Norm

Norm,
It was a hot day for a tour but fun. We sould have put some card board under the t's to catch the oil drops. I hope we get invited to see his collection again.
You may have joined the broken crank club.

Well, I started my investigation today as to what happened to the transmission. It might not be as bad as I thought it would be. Maybe no serious expensive damage. I will know more later. I think I will take off the hogs head for this one. If you will notice the detachable ears on the low band are missing from the picture, and something appears to be under the brake band, like maybe the end of the low band. This might have been coming on for a while, because the low band would slip from time to time, and I would tighten up but that didn't seem to help. I could tighten it up to where it would actually drag, and then back off until it didn't. Anyway, something caused the detachable ears to come off and that's what I will attempt to find and repair. Hopefully no major parts were damaged.
Norm

Sounds like you've got a Big Bang Theory!

Norm- I think you will find that there is Kevlar lint in every nook and cranny of your engine. Unless that mess all happened VERY quickly and the engine got shut off before the lint had a chance to spread, you will find the kevlar in the upper oil feed holes to the mains, in the rod bearings etc. I know that is not what you wanted to hear, but it is better than ruining an engine.
Dan

I plan to pull the hogs head and the inspection plate under the engine. I will also check the inside oiler when I pull the hogs head. It was running just fine. I went down a steep grade going about 40 MPH and then up another going about 25 and then down a gradual grade. I came to the corner and made a right turn. It happened so suddenly, I might have pushed the low pedal, but don't remember. It locked up and the wheels skidded to a stop. The engine wouldn't even turn over with the crank. Unless it was starting to go before that happened, I think it didn't have much time to spread, but I will certainly inspect everything very well before I run it again, because It could have cracked something? Anyway I left about 20 feet of skid marks.
Norm

Looks like the lining came off the band and spun around. I believe you an see a part of the ear sticking out of the lining. Hope the band hasn't cut the drum.

Here's my guess - Broken drum.

Looks like the low gear drum broke because there was slippage from being too loose or drag from being too tight. It broke while turning while driving. If you shifted into low pedal it was too loose and you were going too fast for low pedal. If you went around the corner in high it was too tight. Reverse and the brake appear to be O K.

Fella who owns this nice racer was on Ormond Beach FL sand during the 2002 run, and the low drum blew apart.

No other damage, but I remember him telling me the same thing.......those Kevlar particles were everywhere in that engine!!!! Took him a while to get it all out.

I repaired one a few years ago that had the reverse band totally unravel when the drum broke apart.

A more recent big bang with the same symptoms had the triple gear peg shear off after a loose screw got between the triple gear and drum gear.

Tim was right!
Norm

If you want to dance with the devil you have to pay the price. On the other hand God invented trees and cotton and they are not from the "dark side".

Seriously, Kevlar is a very strong substance and will outlast several sets of drums, while cotton and wood wear out and are inexpensively replaced. Kevlar works very well and lasts a long time but is difficult to adjust unless you know exactly how to do it. You can easily break your drums with improperly adjusted Kevlar. It has been proven yet some folks love it. Mostly flat landers who are not stressing their transmissions. I have a library full of lint stories and use wood in all of my transmission and have never broken one.

Breaking a trans. drum is not something new. It has also happened using cotton linings long before Kelvar was invented. I agree that using Kelvar you run a greater risk than cotton or wood. I have been using Kelvar for approx. 10 yrs. without any problems. I adjust the bands on the loose side compaired with cotton. Being careful not to allow much slippage when using the peddels reduces the chances of breaking a drum. Running a screen oil filter under the trans. cover makes a big difference on keeping the fuzz out of oil passages. Also, making sure your drums are polished makes a big difference in the life of drums and reducing fuzz when using Kelvar.
Happy the problem is only a drum......much less expensive than a crankshaft.

The bands should fit precisely to the drums no matter what type of lining is used. This can only be accomplished by fitting the bands to a drum outside the engine. Then the bands must be carefully installed on the drums with the hogs head removed. The bands cannot be installed with the hogs head in place and remain aligned. They will be bent out of shape.

With Kevlar, when the bands are shaped properly to fit the drums, they rarely need re-adjustment once they are initially set.

Art Wilson

Hi, Art.

Wood band liners are kinda' stiff, and conform the band to their correct shape. I've slipped them through the inspection door more than once. I've never been able to extract a well worn one without breaking it, however.

rdr

I have wood bands on the 26 roadster I used in Kanab. Those bands have been on that car for 15 years and no problems with it. I rarely have to adjust them. That is the car I usually take on the long tours.

I have Kevlar bands on the 26 touring and have been using them for 10 years without a problem. they are smooth to use and no problems so far.

I put Kevlar on the 22 Roadster and ever since I installed them about 18 months ago the low has felt like it was slipping. As you can see by looking at the pictures, the low is adjusted much tighter than the brake or reverse. I didn't separate the drums when I installed the bands, but I did notice that the low drum had some low spots that looked as though the previous band had not been in contact all the way across the drum. That drum might have been cracked before I put the Kevlar bands in. It seemed to need adjustment almost every time I drove it and the pedal would go to the floorboard, so I would adjust it to get about 1 1/2 inches above the floor. Anyway, I don't think it was the kevlar that caused it. I think there was already a problem before I installed the bands.
Norm

"I think there was already a problem before I installed the bands."

Agreed!

Since there are now two threads on this topic I will repeat my response to the other one here as well;

Norman,

In your top photo, it looks like the low adjuster is screwed waaaay far in. Could the band have been running a little too tight?

Also, if your pedal cam is worn, you will get very little lateral movement of the pedal shaft and therefore will have to adjust your band very close to the drum so that you can get it to grab at all when the pedal is pushed. This will also give that mushy feeling you're refering to.

I think you have nailed it Jerry. The cam does move a lot with the hogs head off, but when it was installed it didn't seem to move very much at all. it moved about 1/8 inch I'm talking about side movement of 1/8 inch and bottomed out but it felt like it was slipping. I think it was slipping and that is why I kept adjusting it as the pedal would hit the floor. It was almost to the floor when it began to compress the band. Possibly the pedal or shaft could be bent.
Norm

I pulled the engine & transmission today and I found that the low drum is in 3 large pieces and several small pieces. Most of the kevlar is in the area of the transmission, but some threads in the crankcase under the engine. I intend to clean everything well including the oil lines before I put it back together. I have a couple of other transmissions and will go through everything and if necessary rebush the gears.

I think I found out what was causing the trouble. It is most likely what I saw when I relined the bands before. The low drum looked like the band had only been touching in places. I think what I saw was black from the drum having previously been overheated.

The cams on the low pedal and the shaft are quite worn and I am going to order a new shaft and cams. I conclude that when I got the pedal to bottom out it was really too tight, and I pushed very hard thinking the spring was too strong, but really what was happening was that it just began to move when the pedal was almost to the floor thereby slipping. It would just not get tight. But the adjustment was already too tight and so it was both slipping when I applied the pedal, and also dragging when it was in neutral, high or reverse.

I don't think the kevlar was the cause of the problem but it agrivated it.
Norm

Kevlar is fine to use as a band lining, however it is not very forgiving. If you are using cotton bands, go ahead and just stuff them in through the inspection cover. But, if you are using Kevlar I don't recommend you do this. There are a few other things that I always recommend be done when installing Kevlar bands to minimize any problems.

1. Remove the hogs head. Don't try to stuff them in through the inspection cover. You will need the cover off for several other steps anyway.

2. Make sure the bands are round. Place them around an old drum or some other round object and make sure there are no kinks in the metal bands.

3. Don't make too big an overlap of the kevlar at the ends. You want to have a fairly good size loop in the middle when you start riveting it on.

4. When the ends are riveted, work out the excess loop in the middle. What you are doing here is compressing the band material and forcing it out against the metal band. This makes it conform to curvature of the band instead of making little straight sections between the rivets.

5. Repeat step 2 with the band lining on - make sure they are round. The reason is that when the band is loose you don't want any of it touching the drum, and when you tighten it you want the entire band to grab the drum.

6. Inspect the cams on the side of the hogs head, and on the pedals to make sure they are not worn. Repair by welding and grinding, or replace them if they are worn. Any wear here means you are pushing the pedal down and it is not moving sideways to tighten the band. This lost sideways motion means you have to run the bands tighter to compensate - not a good idea.

7. Install the bands with the hogs head off. Try not to stretch them out any more than is absolutely necessary. The goal is to keep them round.

8. Install the hogs head and finish assembling everything. Adjust the bands so that when you push down hard with your foot the pedals stop about 1 - 1 1/2" from the floor boards. Also make sure that you are not close to having the cams go over the end of the cam onto the flat spot. If this happens, the pedal will not return when you remove your foot (not a good thing if you want to stop).

9. Repeat the following 3 times - "Low pedal good - high pedal bad".

10. Go for a short test drive - about a mile or so. Readjust the bands as in steps 8 and 9. Only take up as much as possible to return the pedal to the 1 - 1 1/2" height. Resist the temptation to go more.

11. Go for a little longer drive - 2 miles. Readjust the bands again.

12. Keep driving and adjusting. You will find you will be able to go farther and farther between adjustments each time. Within a few adjustments things will seat in and you won't have to do more than an occasional adjustment.

Kevlar will last a while, so it is worth it to take the extra time to do all of this. Once you get the job done, you won't have to be bothered with it for a long time.

I'm sure there are 100 different ways to do this, but this is the way I do it and recommend it be done.

Dave S.

Both kevlar and cotton bands when damaged can clog oil lines and spin fibers into all parts of the engine. To my knowledge wood does not.

I am not sure why the aggravation and potential engine damage is worth it. Are there any wood band horror stories out there that contradict this?

Vince M

You can burn up a wood band if used as your only brake, so I've heard. I believe the brake drum is heftier than the others, so more able to generate and dissipate excessive heat. And it's always slipping - never locked like the others.

Wood low and reverse, combined with kevlar brake might be a good compromise.

With four wheel brakes, there's never a worry with wood on all three drums.

rdr

I found in my pile of parts a very good low drum and brake drum. The reverse drum in the existing transmission is good and the brake drum would be useable,but shows some scoring. I found one that is smooth. Anyway I found 3 good drums. I am going to use kevlar, because, I have had good experience in the past with it if it is adjusted correctly. My mistake with this transmission is that the low shaft and cams are very worn. In order to get 1" from the floor, I had to tighten the band too tight. You can see that by looking at the first picture. The adjustment was very far in. The pedal would bottom out so I tightened it some more and finally it was dragging all the time and overheated. I am going to replace the shaft and cams and that, hopefully will cure the problem.
Norm

Snake that oil line before you put it back in the car.

Might also have your replacement drums magnufluxed for good measure !

Norm-
Make sure you get replacement transmission springs that are the right length.

Would someone please remind me who makes 'em?
-Keith

Here's the latest on my transmission. I found a very good low drum and a better brake drum than was in the transmission in my spare parts. I took them to my machinist to get a new drive plate bushing installed. He checked all the others and the straightness of the main shaft and all is good. I will be receiving my re-bushed parts Wednesday. This morning I sent for the gaskets, and bands. I also noticed that the magneto has been lightly scraping on the very edge of a couple of the magnet keepers. I had shimmed it and it was just a little less than 25 thousandth at the closest place. I ordered a laminated shim so I can get a better clearance. My existing shim is 30 thousandth thick and with the laminated I can take it down to about 25 thousandth. That will give me about 30 thousandths clearance from the ring and it should not scrape any more. I'm glad I caught that before it did any damage to the magneto. I also ordered a new low speed shaft, low speed cam and low speed notch.

I think when I get it all together I will have a smoother running car, and hopefully no more bangs. When all the parts are in good condition, a Model T will run a long time with very few problems. Sometimes, though for us amatuer mechanics, it takes a "big bang" to learn the importance of getting things right the first time.
Norm

In a weeks time seems like you just about got it
sorted out. Alright!!

Norm-
I'm glad to hear that things are coming together. While you have everything apart, check your pan to make sure it is straight. If it's not, send it to someone who can straighten it!
-Keith

It seams to me the guy who made and sold the transmission springs got too busy and only sells to parts suppliers now.
They are a must anytime you have the bands out.

I wouldnt put anything in my car by choice if it may cause major engine and/or tramsmission damage. Not if there are other options that work as well or better. just doesnt make practical sense.

Vince M

I make the band springs being that are being discussed. It is true that Lang's is now the distributor for these springs and has been for the past few years. It got to be to much work for me to run to the post office every day to see if any orders came in, run home, do the paperwork, pack up the springs, run to the bank, then back to the post office to mail them, all for an $8.00 sale (that's net sale - not profit). Lang's specializes in selling Model T parts - that is what they do. They are set up for handling web orders, phone orders, fax orders or mail orders. They can handle credit cards, and can ship any way you want. Doing it this way makes things much easier for everyone. Plus, if you call you may get to talk to Trish!

Lang's part number is 3425BQ.

http://www.t-parts.com/BandSprings.html
http://www.modeltford.com/item/3425BQ.aspx

Dave S.

I believe I found the true cause of the "Big Bang" and would like to pass on some pictures so that others in the future might avoid this expensive and time consuming problem. Today I have been cleaning up the engine and transmission preparing to reassemble everything. I am still waiting for some parts, but I thought I would clean things up while waiting.

As I was cleaning the hogs head, I have been very carefully inspecting the operation of the pedals and the pictures show what I found.

This car has Rocky Mountain Brakes and I noticed that the link between the low pedal and the clutch has interference with the welded arm on the brake pedal. The link was installed backwards, probably installed after the starter bendix cover had been installed. This improper installation caused the clutch pedal to bottom out before applying the band and therefore caused the low band to slip.

The first picture shows the link with both the brake and low pedal fully back and inoperative.

The second picture shows the interference. In this picture the brake is off but the low pedal is depressed. No wonder I thought the spring was too tight. I was actually bending the pedal trying to push it harder. Every time I tightened up the adjustment, I would get a little compression of the band but then it would slip so I tightened it more etc. The pedal was never able to compress the band enough.

The third picture shows the link installed correctly. I will check everything when I get it back together and if necessary will grind a little off the brake lever, because the clevis touches the brake lever now. I don't know how it will be with the floorboards in place.

Anyway everyone who has Rocky Mountain brakes, check the link to be sure it is correctly installed.
Norm

Norman

Nice sleuthing on the cause. Good to know, and I remember when installing Rocky's, using the Rocky cast pedal w/integral bracket, checked to be sure of action. Even did some grinding on that lower pedal fitting to give it more streamlined shape.

Good point to remember.

Thank you for posting that and clearing up the mystery.

Norman,

Great to know. Those little things can drive you crazy. I had a somewhat similiar problem with getting the clutch band adjusted properly. I had to tighten the band about every 30 miles and just could not figure out why it was taking so many adjustments to keep the band tight enough to hold the drum for low. I finally found the problem after about 6 adjustments. The pin (actually a bolt on my car) that holds the pedal to the shaft had broke but stay in the shaft. The broken bolt let the pedal spin on the shaft just enough to prevent a solid grab by the band on the drum. New hardened bolt in the shaft and it now works great. A 10 minute fix. Luckily I didn't brake the drum.

Very good info thanks guys.

Latest on "bang"
I have been working on it since Saturday. Today I got the radiator on and started it up. I had the rear wheels jacked up and it runs. when I put on the brake or push the reverse, it kills the engine. I started it about 4:00 PM. I think I still need to do some adjusting. I also need longer springs. When the ears are apart the springs don't even touch. I ordered the longer springs today and am going to take tomorrow off. If I adjust the low loose enough not to drag, the pedal sticks down. If I tighten it up it drags as above. I have not even tried to drive on the road yet. Just with the rear wheels jacked up. I am pretty sure it needs longer springs. I will let you know later how things work out.
Norm

Gotta wonder if your bands are still round. Do you think you might have kinked them when installing them? Sounds like a high spot somewhere, but I'm certainly no expert.

No, they are round. I used a different band for the low because the old one got kinked in the big bang. The low drum is also a different drum. I put the bands on before the hogs head and soaked them overnight. If you see the posts above, you will note that the link between the low and the brake prevented the low from going all the way down befoe the bang. I turned that link around and now the pedal goes down below the floorboard. It sticks when it is down. It did not stick before because it couldn't go all the way down. Today I loosened the low 2 full turns and I can now turn the crank without pulling the car forward, so I know it is now loose enough, but it sticks down. I have ordered the longer springs and will wait until I get them before doing more work. I think I have found all the problems. This was caused by a combination of things which all compounded on one another. I have also ordered a new set of springs for the 26 touring, because the pedals tend to stick on that one too, but not completely like this one. When the ears are apart, they don't even touch the ends of the existing springs.
Norm

Norman,

Have you figured out why it stalls the engine when you press down on the reverse or brake pedals? My concern is that you did not get the triple gears timed correctly. If not timed correctly the drums will bind up and not turn in relation to each other. With the rear wheels jacked up, the entire drum assembly will spin with the flywheel and will spin the rear wheels. However when you step on the pedals to stop the drum you are actually going to stop all of the drums and stall the engine. Kind of like mashing all three pedals down at once. Were the three drums able to turn freely in relation to each other before you finished putting it all together?

Dave S.

It was very interesting to me as I have just installed old mountain brakes in my 21 with an aux jumbo trans. I had to install extra emer. brake shaft to install equalizer this moved it back about a foot so that rod of brake ped. flexed and wouldn't work after much trial and error bigger rods etc. I used 1/4 -1 1/2 on both sides of welded pedal and ground out slot to go over casting to clear this allowed me to drill hole farther down on brake shaft making a longer throw on aux brakes ken

I took yesterday off. Tuesday I just started it up and it was too tight. It would run with the rear wheels jacked up. Yesterday, I did one thing. I loosened up the low and it will crank in neutral without moving the car forward. So I know that I had the low band too tight. But the low pedal sticks down. I changed the position of the low high link as you can see in pictures above. I think today I will check the length of that link. Maybe that will fix the problem. If not, I will have to wait for the new springs I ordered.
Norm

Well,
Today I am in the process of removing the hogs head again. Something is wrong with the new pedal shaft or the new cams I placed. The pedal all the way back is about half way down and when I loosen the band enough to allow the low drum to turn the pedal is below the floor board. When the pedal is all the way back it is not as far as the brake pedal, but about 1/2 way between the brake and the floorboard. It is not the high speed clutch, because I am making this determination with the pin out of the clevis. The holes on the shaft are either drilled in the wrong place or the cams are ground wrong.
Norm

Hooray! Hooray! I got it back together again today and it works! I had to bend the pedal back.

This is what I think caused the whole problem and what it took to fix it. It was NOT the Kevelar bands. The cause was the interference between the low high link and the brake extension as pointed out in the 3 pictures above. This caused the pedal to bottom out about 1 inch above the floorboard. The cam would not compress the band because of the interference with the pedal. I thought "the spring is too strong" and so I pressed down hard. It still slipped. Then I tightened up the band. It worked for a while, but still seemed to slip and I pushed down hard. I tightened down more and it was too tight when driving but still slipped when I applied the low band. This continued until the drum overheated and collapsed.

The transmission rebuild replaced all the bad parts and one bushing. After I put it all together, I found that the low applied below the floorboard, but when I tightened it so it would apply above the floorboard it was too tight.

Second time I removed the hogs head, I bent the pedal back about 3 inches and then put everything back together. Success! Apparently my pushing down hard had bent the pedal down and so it was not the cam worn, but the pedal was bent out of alignment.

So I think the cause of all the problems was the link being placed backward causing the pedal to stop above the floorboard, and my pushing hard bent the pedal which compounded the problem.
Norm

Wood wood've worn out before the drum.

Success.
Today I made the 50 mile round trip with hills and at least 50 traffic signals and stop signs. The bands work. I drove one way and there was a little slippage. When I got there I adjusted the low and it went all the way home without a problem. It even works going uphill. This is the best this T has done since I got it.
Norm

Norm,

Been following the story of the Big Bang and glad to hear the happy ending.

It's a great feeling when you get it right and it shows.

Now if I can just get the '27 out of storage and back on the road myself....

Larry Bohlen, Severn MD