MTFCA Forum

Describe "band chatter" please.

It's what happens when the conductor isn't zipped up.

The following is my experience with band chatter. When coming to a complete stop after applying the brake I experienced chattering just before the car stopped. It seemed to intensify when coming to a stop on a downhill grade. It was noticeable when I drove into the garage and came to a stop as my garage is downhill from the street. At the time I was using Kevlar linings. When I switched to Scandanavia linings it was reduced a lot. Automatic transmission fluid but it did nothing for the chatterlng.

Hard to describe the sound. It was a vibration of sorts, a very fast on and off grabbing of the lining.

I found that the occurance is worse with certain oil but was not related to the viscosity. Adding a little synthetic oil reduced chatter.
Art Mirtes

What I have is a harsh, annoying noise during engagement rather than bucking or grabbing. Low actually engages fairly smoothly. Reverse engages quietly and smoothly. The trans brake is smooth and quiet and high engages smoothly. The car rolls easily in "neutral" and shows no tendency to creep. The objectionable noise begins as soon as the low band begins to engage the drum, before the car moves even an inch, so I don't think it is gear noise. Once rolling in low there is some gear noise, but I think it is well within normal range. The car runs very well, with very little vibration. The noise does not sound like metal-to- metal to me. It sounds more like a squawky brake noise from a drum brake that has had a little fluid or grease leaked on it. I suspect that the low band is grabbing/releasing at a high frequency as it engages. Bands are Kevlar and the oil is a light bodied synthetic. Operating temperature has no effect. The low pedal stops about 2" above the floor. The hand lever stops about 2-3" ahead of the seat, and has a clear neutral when straight up, and engages high when well forward. I can detect no slippage in any gear at any speed and I can't hear any noises from the transmission area when idling the engine with the hand lever in neutral. To sum up, would it be considered normal for the low band to be much noisier than the reverse band, the brake band, or the clutch?

I don't know what is causing this problem. For an easy try, use a different brand of oil, maybe a nonsynthetic 10--30 at the next oil change. It would be easy and inexpensive.

Could the transmission band be out of round? It’s possible to install a band so it will pull around the drum when installing them. But if it’s got a slight hump or curve in it it still will be out of round just slightly when you begin to tighten with the pedal when driving.

Couple things come to mind
Worn cam and/or notch on the low speed pedal
Worn low band lining. Look for thin or nonexistant lining at the top ends of the band where they compress.
What you are experiencing does not sound like band chatter.
I would remove the trans inspection cover with the car not running and depress the low speed pedal by hand and see how the notch and pedal cam engage. If worn out you will get little band compression. Not uncommon.
Then look at the ends of the low speed band and see if there is missing band lining or very thin lining at the ends.
That's all that comes to mind.

I'll take a look at the band lining thickness and the cam. FWIW, the band seems to hold just fine. It just makes more noise when engaging than the reverse or the brake.

It sounds to me like what you are hearing is the planetary gears if it is only a noise and only in low, not unusual for low to make more noise.

I lifted out the floorboards and looked at the transmission. No leaks are evident at the pedal shafts, and they appear to be new, or near-new and fit in the cover snugly. The low band pedal shaft moves toward the middle of the car when the pedal is pressed down, and it feels like it is clamping down on band material. The ramps on the brake pedal shaft appear new. All three pedal shafts appear to be free of wear and have a very positive feel to them when moved by hand. The reverse pedal does need adjustment, but it moves inward when pressed as if the cam/ramp is in very good shape, and the adjustment screw.... *** EDIT: *** I see that the large adjustment screw on passenger side of case is for low band, NOT reverse **** ...has an inch or more of thread exposed. The reverse seems to hold well, but the pedal is at or very near the floor when pressed hard.

Pat- your forum profile states "Model Ts owned: None (yet)"
Here's my question: (not trying to DIG, just trying to solve your problem)- If the T in question is not yours, have you been told that kevlar bands are present, or have you actually seen the bands?
The reason I'm asking is because over the years I've owned 7 Model T's. All had kevlar bands and none chattered. I currently have a '21 Depot hack that has WOOD bands that do chatter. The instructions that came with them 9 or 10 years ago there was a warning that they may chatter if the clutch is feathered. I quickly learned to let the clutch grab-n-go. Clutch adjustments are very rare. About the only time the chattering is a pain is loading on a trailer.

Profile is out of date. The car does have Kevlar bands and is in excellent condition overall. I will practice "grab & go".

"Grab and go" is the rule for first and reverse gear. The sooner the band stills the drum and drive is transmitted, the better. Slipping the band is not the way to go. It is unavoidable on the brake drum, as the band slips until the car is stopped. The brake is the only band with which I have ever experienced chatter, to varying degrees. Usually it is worse the closer you get to stopping, and given a technique of letting up on the brake close to stopping, I can usually drive around the chatter.

Allan from down under.

I have 7 T's and only one of them chatters when applying the brake. They were all rebuilt the same way with the same Kevlar bands and all transmission components were within spec. I could never figure out why. Consistent with the "grab and go" theory, I added AC brakes on that car and set them up so they do the primary stopping but with greater application of the brake pedal the brake band kicks in and that is usually right before coming to a full stop. No more chatter!

"Grab & go" is pretty much the go-to rule for any friction coupling.

This oil will solve the problem. I believe it's made from snakes.