I've lost low speed in my 20 touring.
High, Brake, and Reverse all work as expected.
Was driving in Low Gear at a low-medium speed when the pedal suddenly lost resistance and went to the floor.
I was able to make it home in high gear. There were no weird, new, or unexpected noises from the transmission.
I did some searching on the forum and decided to open the transmission cover. Here is what I saw:
IMG_0922-111.jp2 (247.3 k)
Does the notch turn and compress the band when you press the pedal?
The thing that I see is the brake band spring has twisted its way into the brake band ears on both ends, likely binding things up and preventing the band from clamping onto the drum. Not sure how this would mess up the operation of the low band.
To fix the brake band issue, tie a long piece of string to the middle of the band spring to keep it from falling down into the transmission. Stuff rags all around the area to keep parts from falling into the transmission, then remove the adjusting nut and washer. Then pull the band ear back and get the spring out and unstuck from the band ears.
I recommend you get a new band spring, and perhaps consider installing washers on both ends of the spring to keep it from winding into the band ears like the old one did. Tie some dental floss to the washers prior to installation so that you can retrieve them if they try to fall down into the transmission.
(Message edited by cudaman on August 06, 2018)
Mark, that's the brake band that has the screwed up spring, that's not giving Michael the problem he's got.
Interesting .. I was thinking about the slight chatter in my brake today. The best suggestion I got from the forum was that a slightly worn drum might place the left band ear in the wrong place and that inserting a washer between the hogs head and the left ear might correct for this.
I saw that right after my initial post and edited it accordingly.
I also see that the low band ear is chewing away the end of the adjuster and had rounded it off, looks like you need to get a new adjuster with an undamaged surface for the band ear to fit against.
True Mark, that needs fixing too.
I'm thinking a pin is lost to have lost pedal all of a sudden, cam pin? or the peddle pin?
If it looks like the new adjuster doesn't have enough of a shoulder to prevent the band ear from chewing it up, you can install a hardened washer to provide more surface area for the band ear to bear against.
If the low speed notch pin is sheared it will be obvious, press the low pedal and watch for the notch to rotate and compress the band. If the notch doesn't rotate, then the pin is likely sheared.
I don't see that. It looks to me like the cockeyed spring is on the brake (left) shaft. The low (middle) spring looks normal, but the end of the adjuster looks worn/boogered up. See how it's extending into the band ear. If the answer to John's question is yes (notch working normally), I think you're due for a new adjuster that will seat properly against the band ear. A temporary fix would be a washer between the adjuster and the band ear. Before removing/installing small parts stuff rags in the open spaces to catch anything that you may drop. Count the rags going in and coming out.
Steve, see my edited post, thanks.
Everybody types faster than I do.
John, yes it does, it just does not compress nearly enough to cinch down on the drum and create any type of locomotion. But the notch/cam thing seems fully functional.
I had my better half turn the hand crank while I inspected the surface of the Low Speed Drum for any obvious signs of cracks. I found none.
Something that is not obvious from my picture:
The ear on the right side (bottom of picture) for the low speed band, does seem to sit a little lower on the bolt than the other ones do. I've added another picture to illustrate. Not sure if this is something I should be concerned about.
A few questions:
Is it possible for the band adjustment bolt/nut to have backed out or jumped threads on a hot day? (95*F)
Is the wear on the shoulder of the low speed adjustment bolt normal? (It looks like the ear may have worn a bit more than I remember it.)
Should I put a washer where the low meets the bolt?
Mark, as Frank also mentioned, I believe you may be referring to the Brake band. Thank you for the tip on that, I was wondering how I can prevent the spring from doing that. I think I will go the route of adding washers.
And I'm even on my tablet, where I have to type with one finger instead of touch typing!
Seems like most of my questions were answered before I could ask them.
Thank you all!
I think I will try Steve's suggestion of adding a washer between the adjuster and band ear to see if this fixes the problem.
Does anyone have suggested specs they can provide on the washer?
I can pick it up tomorrow before work.
I'm due for an overhaul of most of the gaskets/seals in the transmission and differential this winter, so I will add the new adjuster to that list.
I will report back with my results after I add the washer.
1 Did you find the adjuster lock nut loose? It would be if the adjuster had backed out. Jumped threads? Extremely unlikely. They would have to be mighty badly worn.
2 No, that wear is not normal. As I mentioned above, a washer should work until you get an un-chewed adjuster.
Now here's something else to check. That ear sitting lower than the other two made me think of it. Is all the lining still on the low band? Old cotton linings do deteriorate and come loose. If all or most of it has come off the band, that could be your problem.
Why not just take the adjuster with you when you go washer shopping? As Mark says, get a hard washer.
I suspect that the brake band itself has broken. It is a bit uncommon, but I have seen it happen a couple of times. Similar symptom: the pedal just goes right to the floor. Good luck with your project, Bill.
That is what I suspect too, or a portion of the low band lining is now gone. That would do it too.
On the passenger side of the low band, I can't really see in that photo of much lining under the leading edge of that low band. There should be some projecting under the lugs on that low band.
Would expect to see this, good band lining extending out from the band lug ears on each side, like this photo below:
It's not unusual to see a worn low speed adjuster, but that's not worn enough to cause the pedal to go to the floor. You need to remove the band and inspect the lining, it's probably gone.
A couple things to look at. Jack up a rear wheel and rotate the engine in high gear. look carefully at the low drum all the way around. You might find a crack in the drum. When this happens the lining will wear very rapidly. The worst that can happen is to have the drum collapse and the whole car stops and you can't even push it.
The other thing is the low speed notch. This will be at the left side of the ear of the band and it should move with the pedal shaft as you depress the pedal. There is a pin in it which you can see in the picture The pin is still there. It could be broken. The notch should rotate with the shaft as you push the pedal. You will push down a short distance to the neutral position and then when you push farther the pedal should move to the right and compress the band. Many times this notch and the cam which is attached to the hogs head become worn and as you push the pedal it will not compress enough to make the low gear engage.
So these two things I would check: cracks in the drum and movement of the notch to compress the band.
I had the same thing happen & it was a broken band.
It cracked right where it connected to the ear.
I had the same thing happen.
It turned out to be the band cracked & broke at the ear.
UPDATE! Read all about it! (Bill, Dan, and Mark, you will want to read until the end.)
So this morning, I head out to the car to pull the Low Speed Adjuster off so I can head up to the hardware store and obtain a washer... the removal process went without incident.
However, when I started up my Tahoe to head to the hardware store, I put my foot on the brake to shift into drive and the brake pedal went straight to the floor.
Brake fluid went all over the ground!
Needless to say, I didn't have time to go to the hardware store before work. No hardware store = no washer.
This turned out to be a blessing in disguise.
With my newfound extra time, I decided to investigate/remove the Low Speed Band, which required that I also remove the Brake Band.
In removing the Brake Band, I found out that it is indeed broken/cracked (underneath the ear). As was the Low Speed Band (cracked just where it meets the ear)!
Boy am I glad that my brakes went out on the Tahoe! Otherwise I might have "temporarily" solved the Low Speed Band issue, only to find myself without the transmission brake!
Thank you all for the suggestions and help!
Two more questions:
1) The Reverse Band is of a different design than the other two, and it says Raybestos on it. This band is much more rigid and obviously not broken and has lots of lining left on it. Is there any trick to getting the ear off of this style band? Is it even worth taking off if the lining seems good?
2) While I'm in there, what else should I be checking for? I assume check the drums for damage, anything else?
Rhetorical bonus question: What lining material should I go with? (Ducks and runs for cover.)
Rhetorical answer: It depends on how you drive.
If you have a light foot (let the drums slip a lot), wood or cotton.
If you're aggressive with the pedals (slip the drums only enough to get moving without stalling and hold the pedal down hard), Kevlar.
I always figured if you drive like Steve's second example, that any material will last a long time, so no high tech wear proof material is needed.
Sorry to hear of your run of bad luck. You seem to have several parts in your transmission that are at or beyond their service limit.
Because of this, if it were me, I would go ahead and remove the reverse band, then give all of the drums a careful inspection. I would also check the pedal cams and corresponding notches a carefully for excessive wear and replace them if necessary. Also check for excessive wear of the pedal shafts and their corresponding holes in the hogshead.
Check your band springs to make sure they stand up straight and haven't taken a set in a bent position. If they are bent, replace them.
Buy a new low speed adjuster to replace the chewed up one. If you decide to use washers to help give the springs and adjuster more area to sit against, you may have to grind a flat on one side of the washer to allow the pedal shaft to sit down fully into the notches in the band ears.
Keep us posted on your progress and good luck!
True, Hal, but cotton does deteriorate with age and eventually goes to pieces. I expect wood will last better.
Thank you all for the tips. I will likely replace most of the band related components (springs, notches, etc).
Is there a way to tell which band material I currently have?
Itís definitely not wood.
If I posted a picture would it be helpful?
Cotton linings are brown, as in the photo above.
Kevlar leans more toward yellow.
I think I have cotton
Regardless of the type of lining, do not let the band slip any more than necessary. The bands will wear a lot better and the drums will not heat up or crack. Of course, this does not apply to the brake band. I that case I would suggest after market brakes such as Rocky Mountain or disk.
I switched to Kevlar from cotton recently. I find that it takes much more peddle pressure to get a firm grip on things.