T-20 problems (teach and coach me please)

[Rusty-Gunn]

Thanks Mike.

[dirtdobber]

the instructions are for the "floating" U-channel type. Mine have a pivot bolt ....... Will the fact that mine are pivoted make a difference with these instructions?

It might make a difference. It will depend on how your plungers attach and what they attach to. If you are still using the U-channel with that little channel shaped washer thing under the bolt head, then I believe the instructions will work fine. Those channel shaped washers keep you from over tightening the bands. If your plungers are directly bolted to a popsicle stick then it might make a difference. Let's understand what's going on with the plungers...

Of course, the plungers are connected to the brake bands in the transmission. When a plunger is pulled outward, it applies the brake and thus directs torque to the output shaft. In theory, if one were to tighten both plunger bolts too much, both bands would be engaged at the same time and your transmission wouldn't work. So, imagine as you drive your machine pushing and pulling on the laterals, as one plunger is pulled out to engage the brake band, the other plunger must be pushed in to disengage the opposite band. And, you want enough "slack" between engagement and disengagement so that both bands can be disengaged at the same time (thus the "neutral" position with the laterals). If you have too much "slack" in the plungers, I guess it's possible you could run out of travel with your laterals before a band becomes engaged.

Can you post a pic of your setup?

[Rusty-Gunn]

Dirtdobber... thank you.
My plungers are indeed U-channel, with the keeps installed. I followed Amphibious Drew's instructions on how to drill/tap a pivot bolt, which works fine. I never did ask if this pivot mod would require "special" adjustment instructions or not at the time.
What you wrote is making sense in my mind. I've seen Brandon's T20 video how-to regarding disassembly and reassembly, and its making more sense now.
I have searched more threads here, and youtube videos to learn more. Thank you. And thanks to everyone.

[msafi65]

Don The noise you are hearing when turning is probably band chatter. It happens when bands and drums get glazed and very slick. Testing for this I stop the vehicle on a fairly steep downhill with the sticks. Just letting enough pressure off sticks to allow movement then stoping again. If I hear any noise that sounds like screech or low groaning it's band noise. Not necessarily bad bands but noisy for some reason. Many times I pull apart and use a green scrub pad on bands to take the shine off the contact surface. Drums get put in lathe and get cleaned with sandpaper until surface is dull grey. Shiny enough to see yourself isn't good for bands to grip on. Another thing to remember is if a T20 will drive forward on both sides and stop both sides to steer , the bands are still working. I'm not saying there good just they aren't broken or out of place. Most reverse problems are from the shift collar not engaging the reverse teeth properly. This can be damaged teeth or collar and shift pin problems.

[Rusty-Gunn]

Thank you Mark. There wasn 't any unusual sound. I was asking if the bands did wear out to rub metal to metal what sort of sound might it make. More for education purposes here.
The pins are fine, I checked them both. Ionce I get a bit of free time I'll re-adjust the plunger bolts to tighten up the bands a bit and see if this helps.
The wife already insists I order new bands/gasket kit anyway. We'll go from here.

[Rusty-Gunn]

We got the bands adjusted by finger tightening all four bolts a few turns. These now feel like they can not tighten any more due to the U-channel bolt keepers.
Our initial testing by pushing the Max a few feet forward/backward shows the machine now has brake effect on both sides, forward and backwards. Neutral on both sides is fine, as well.
We expect to be done putting it all back together tomorrow and test drive it. I'll report our results here.

[Rusty-Gunn]

We got the M-IV done this evening. Initial test run indicates all is well. It turns with authority left/right forward and in reverse. We will give it a long test ride very soon. Thank you to everyone.

[Rusty-Gunn]

Our Max runs fine. We've taken it out of town about 15 miles or so. Just a bit of ocassional band chatter.

Today I ordered new bands, a complete gasket kit, and a few related items.
Once these parts arrive we're expecting to crack open the T20. I might wait a few more rides first, since the trans works good yet.
It will be my first time opening up a T20. I've seen Brandon's YouTube video on T20 band replacement a few times. It seems easy enough. I'll report back here at some point on our progress. Thanks to everyone for the assistance.

[LowCountry1720]

Hello, how did this work out for you? I just bought a Max II. I have only had a chance to run it (VERY SHORT DISTANCE) on pavement to make sure it ran. It seemed to have a tough time turning, almost like a lot of slack. Although I have never driven one before. I am going to jack it up and turn the wheels to see how it goes. IT does not roll forward in gear. I am excited to get it lifted up and check the bearings, seals, etc etc.

[Rusty-Gunn]

LowCountry1720... it ran fine.

Update... At 500 hours we changed out the brake bands, o-rings, needle bearings, shaft bearings, and gaskets. No problem. Rather easy.
Question... which plunger bolts are adjusted to fine-tune reverse?
I have no idea which bolts, top or bottom, works which drums. Perhaps a bit more explaining to me will help. Any takers?

[Toys4Me]

Correction Tops are reverse, bottoms are forward.

[Rusty-Gunn]

Thank you.
When we were setting up to adjust the plunger bolts I noticed one U-channel pivot bolt on the left side had rattled out, giving me poor left-hand turns, especially in reverse.
I screwed this bolt back on using blue locktite, and test drove it for a few hours. No problems. If it comes out again I'll replace it with one that has longer threads, and cut new threads deeper.
It it good to know which bolts are for forward/reverse. Thanks.

[dave phelps]

There's no locks behind the bolt heads?? or pins through the u channels??

[Rusty-Gunn]

Both pins and bolt locks are installed as required. I used the instructions to adjust the plungers out to 20 ounce-inches, "on the bench" but for got to recheck after the T20 was installed. It is very diffecult to do this for me with the engine already installed. I have a disability with my spine/neck to move around in the tub trying yo do this and not be able to see what I am doing. The engine frame is on the way.
BTW the instructions I used are for "floating" U-channels. Mine are modified with a pivot bolt like the older popdickle stick type. I don't think it makes much difference though.
She runs good with the pivot bolt screwed back in.

[dave phelps]

Both pins and bolt locks are installed as required. I used the instructions to adjust the plungers out to 20 ounce-inches, "on the bench" but for got to recheck after the T20 was installed. It is very diffecult to do this for me with the engine already installed. I have a disability with my spine/neck to move around in the tub trying yo do this and not be able to see what I am doing. The engine frame is on the way.
BTW the instructions I used are for "floating" U-channels. Mine are modified with a pivot bolt like the older popdickle stick type. I don't think it makes much difference though.
She runs good with the pivot bolt screwed back in.

Gotcha. Glad your up and goin again��������