What is a Transaxle Automatic Transmission

[z-partsman]

Question..... what is a Transaxle Automatic Transmission? Yet alone where can I find one or can I make one? I found and old artical that had one in a 6x6. Here is their discription.....

"Two sticks start, shift and reverse the six wheels. To go, you push both levers forward. Pull back on them and you reverse. Push one and pull the other to change direction in the length of the machine as one set of wheels goes forward and the opposite set go backwards. Let go of both handles and you come to a stop automatically.

Transaxle Automatic Transmission or TAT as it's called, works this magic with an infinite number of gear ratios from High to Low. The TATs coneshaped drive discs hold the secret that makes it a clutch, variable speed transmission, and differential all in one. You don't have to build or assemble the TAT, you buy it and install it as a unit.

Throttle control is only used when starting up the 8-hp, 4-stroke engine. The TAT takes care of all speed and direction change requirements."
Now.... anybody have any ideas?? I tried to copy a picture but my pc is throwing a fit.

[Mike]

Before I read the part about the drive discs I would have sworn it was hydraulic. I have no clue but it sure sounds awesome. Do you know which 6x6 had that trans?

[z-partsman]

the MI Marauder. it's a home built 6x6 out of ply.

[GREASEMONKEY]

The easy way to explain a transaxle is the comparison to an average pickup truck transmission.
In an average pickup, or rear wheel drive car, the engine spins the transmission-the transmission spins the drive shaft(propeller shaft for you Aussi gents!)-the drive shaft spins the differential-the differential spins the axles-axles spin the wheel's.
In a front wheel drive, or rear wheel drive rear engine car, the engine spins the transmission, the transmission houses the differential, and some portion of the axles. There is no need for a drive shaft, because the differential is internal. This is great for saving space.
The best example of the most basic trans-axle car is an old 70's VW Beetle! It is also great for the fact of having fewer moving parts, less movment, less mantainance! There is no difference in a trans-axle being an automatic, or manual. It's still called a trans-axle due to it's basic design!
The type of trans-axle you are refering to is more than likely mechanical over hydraulic. Meaning that the mechanical part of the drive line controls/powers the hydraulic final drive. Judging by the type of controls you describe, the drive line will be somthing like this.
Engine spins trans-axle, outter axles spin twin hydraulic pumps, pumps push hydraulic fluid through a valving system(the valving system determines the flow direction & volume) the fluid pushes 2 or more hydraulic motors, the motors spin a set of gear drives or axles attached to the wheels!

I hope that this shed a little light, and wasn't too confusing.

[z-partsman]

well.... it's not a hydraulic system, and I do know how a basic drive line works in my truck and fWD car. this thing has NO gears. just an input shaft and output shaft. on the input there is your drive chain sprocket, on both sides of the output there are your secondary drive sprockets.

there is a better way to explain this system to all.... go over to http://www.route6x6.com/memorylane/b...mi6wheeler.pdf

its'on page 6 (or the originals page 81).it has 3 pictures of this trans assembly there. It looks more like it takes place of the belt drive system and trans. It is neat how it instantly reverses the direction of one or both sides with out having to shift a gear selector, and with out it being Hydraulic. I hope that explains better what I am talking about.

Whipper have you seen these?

[Mike]

In that article, it states that you don't have to build that "TAT" but then there is no more information about it. I wonder if anybody has the full plans from Mechanics Illustrated online somewhere? It would be interesting to at least see what brand that transmission was.

[liflod]

I think you're talking about a Dixon ZTR lawn mower Z-drive transaxle. 2 cone cltuches, the more you press on the sitcks, the farther down on the cone the disc rides + higher ratio. Instant reverse. That style trans does not have enough umphh to move a 6x6. My mower does good, but its only drving 2 wheels.

[Mike]

Have those been around for a long time?

[GREASEMONKEY]

By the looks of it, that's a dual directional gear differential. Twin cone gears, what a different way of thinking!

[z-partsman]

I think you're talking about a Dixon ZTR lawn mower Z-drive transaxle. 2 cone cltuches, the more you press on the sitcks, the farther down on the cone the disc rides + higher ratio. Instant reverse. That style trans does not have enough umphh to move a 6x6. My mower does good, but its only drving 2 wheels.

I wouldn't mind giving it a try once though. I did find another link for the plans, but I forget where it was. Said the plans where only $5. not sure if that from way back then price or not.

[GREASEMONKEY]

The ability to transfer torque is the only hold back. Not saying it will not, because I have no experience with this style tranny. I'm just curious as to the amount of torque loss through the tranny. The ability to take a beating, and ability to deliver torque to some degree - is hinged on the type & quality of materials used to make it!
I would love to get my hands on one to disect it. That's the only way to really understand something like that!

[smyser]

The TAT (transaxle automatic transmission) you are talking about is in fact the same transmission used in early Dixon zero turn mowers. Dixon bought the patent to this transmission in the mid-70's, and the zero turn lawnmower was born. It then became known as the 'Z' drive, or Dixon's 'cone drive' transmission. They used this transmission until the last 10 years or so when hydraulic drives became the thing to have. These cone drives are easy to find and have plenty of torque and power for a 6x6 project. By the way the Marauder plans mentioned here was just an article printed in Mechanics Illustrated. The article didn't have enough detail to build a working 6x6, and the complete plans haven't been available since the early eighties.

[Theman10k]

Did you make the Marauder in the end or not as I'm about to make one and wondered if you had a parts list or anything to help me make it at all

[Tomo]

Hi
A variation on the cone system
One vertical 4inch diameter cone spun by engine .It shunts either left or right . The taper contacts a horizontal shaft with 1xdisc with taper on RH and the same again on the LH side . The lh and rh spin opposite directions giving f or rev [cox mowers]

There is a system that is laid out the same with cork faced clutches [greenfield mowers ]
Either of the above system I would dought transmit a heavy unit such as a 6x6
tomo

[SHOTGUN]

This transmission is very basic in operation, older snow blowers use a similar design for speed( only need one side). The cone is small on one end and big on the other, where the cone is contacted by the drum gives the reduction. Friction is used for torque transfer and is adsutable with spring pressure, contact surface area and I believe shift angle(similar to cvt tranny). Torque output would be no different that a cvt when spec'ed correctly(works in 8hp golf cart or 300hp snowmoblie).