Bandless automatic transmissions?

I thought the GM turbohydomatics, ie the TH350 and TH400 and variants were all bandless. One of the reasons they are so durable.

I'd always read that the 604 was the first. I think most of them are bandless now. Not that its a GOOD thing to be bandless... :-/

Ashton Crusher wrote in news: snipped-for-privacy@4ax.com:

One reply.

Either nobody really knows the answer to my question, or the question isn't a very interesting one.

I checked out the THM. It seems the thing has kickdown and reverse bands, so I guess it's not truly "bandless".

Oops, the 604 was the first to have neither bands NOR overrunning clutches. There were others without bands first, but they required OR clutches.

The first semi automatic transmissions (with bands) were the Model T Ford cars.I own a 1914 Model T Ford Runabout Roadster car.I bought the car for $1,800 from a guy (his wife took my money,of course.Just like that guy's wife took my $150.00 for my Blue Heeler Australian Cattle Dog

a few years ago.Doggy owns the couch here) in Sioux Falls,South Dakota in November 1971.Soon after I bought my car,I ordered a set of bands like the kind that are used in General Motors cars.The bands came almost ready for me to install in my car.The instructions said to use a hacksaw and cut an X in the middle of the bands. cuhulin

Steve wrote in news: snipped-for-privacy@texas.net:

Can you think of any other specific models that were bandless?

If you want to sit in front of the computer all day long to find out, try this site...

Happy hunting...

SteveL

snipped-for-privacy@not.a.real.address.com wrote in news: snipped-for-privacy@4ax.com:

Hey, thanks. Next time I want to find out if Fairthorpe or Laforza used a bandless auto tranny, I'll be sure to spend the rest of my life on Rock Auto.

I was hoping some of the gurus who hang out in this group might know a few models off the top of their heads. Some of them make a big deal about having extensive automatic transmission experience, which is why I asked here in the first place.

You know, there is only so much information I can keep in my head, and rockauto is where I keep the rest...

Steve(my brain is full)L

Sorry for the off topic, but what is a Bandless automatic transmissions, and how do they differ from the normal band type transmission?

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how do they differ

They don't have bands ;-)

OK, I assume you want a little more info than that. In an automatic transmission, gear ratios are changed by either holding or releasing different parts of a planetary gearset. You can hold the sun gear and drive the planet carrier and tap power off the ring gear (ratio step-up), hold the ring gear, drive the sun gear and tap power off the planet carrier (ratio step down), hold the planet carrier, drive the sun gear, and tap power off the ring gear (reverse), and many other combinations especially when two or more planetary sets are daisy-chained.

Bands are a convenient way to hold the ring gear locked, since the ring gear forms the outside of the planetary gear package and the band can just clamp down on it. The downside is that they're a little trickier to modulate smoothly than clutch packs, so clutch packs are easier to control via computer. Other than that, bands and clutch packs are pretty much interchangeable. The downside to clutch packs, by the way, is that they have more parasitic drag when released than bands usually do.

how do they differ

THANK YOU for the informative response. That was just what I was looking for, a quick knowledgeable summation.

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What's the name of that Swedish company that makes motorcycles and small engine tools,stuff like that? Huskvarner? (I could cheat and look it up) They used to build some motorcycles that had bandless automatic transmissions.DAF too.And there are Comet torque converters,automatic bandless transmissions.A bunch of others too,I think. cuhulin