Transaxle w/T56 internals?

I understand transaxles have a lot of custom parts, but couldn't one drastically reduce the cost of a transaxle by utilizing premade gears (say from a T56?).

Yes you still need

1. Custom Case
2. Custom Shaft/Spline
3. Custom End Plates

But the rest could be mass produced items

1. Gears
2. Ring Gear
3. Bearings
4. Syncros
5. Bellhousing


Am I over simplifying it, or is there something I'm missing (there has to be,, otherwise I can't imagine this not being done year ago)?
 
This is essentially the approach that DeLynn at Griffin has been trying to do for several years. Check his webpage for more details.
 
The T56 suggestion you make was done here in NZ by an Auckland company several years ago, It spent a lot of time in a ute/pickup with V8 power hidden under the pickup cover doing lots of miles as a test bed, yet I dont believe it has sold in any numbers, I might ring them tonite just for interest sake.
Yes it can /could be done, De Lynn as I understand it ran into a problem when the Richmond Gear company was subject to a major business re-shuffle which meant he had to rethink a lot of the stuff he was intending to use.
Using of the shelf items is great, BUT, who is going to carry any guarantees or warranty claims, you cant expect the donor company to as your using it in an environment untested by them. Given that you might find a large % of potential customers turn to vapor.
I started a thread under -All American Transaxle- or similar, other than De Lynn who was already on track nobody else seems to have jumped in!
 
Z06 Corvette is that -- pretty much a T56 trans axle

accept the diff and axles are on the wrong end. I'm sure somebody else will chime in, but I think RCR is using this tranny combo in at least one of their platforms, but without the driveshaft extension tube thing.

Isn't there somebody else working on a custom transaxle using Toploader internals?

I would love to see a T56 based product with an 8.8 differential. I wonder if the T56 housing could be maintained with a bolt on diff/axle housing on the front? ...Since dreaming is cheap
 
When you get to the details, it is more difficult that you would think. If you put the gearset behind the R&P, that means you:

- need a custom input shaft (expensive), or an 'extension'
- end up with a mile long transaxle (roughly 3')

I *think* the 8.8 is a hypoid gearset so likely would need a different oil than the gearset. I believe the appropriate oil for those will cause shifting issues for most transmissions. If you need two different oils, you will have a much more complicated case and likely will have an even longer unit.

I am working on a one-off using a TKO-600 gear set and 10" R&P. The 10" is probably over kill, but it makes some things easier for me (we race sprint cars...) and there is a good selection of off the shelf bits (like couplers). There are LOTS of compromises to packaging. I expect the T56 would be a bit worse. A typical 4-speed gearset would be easier to package than the TKO.

So currently I have a TKO and a Sprint Center section in pieces spread across my bench, and have drawn out my different options...

I have a Graz in my SLC - and I see no use for 6 speeds with such a light car and a big V8. That is why I chose the TKO - it has a reasonable spread between the gears, and a choice of 5th appropriate for street or track. I will have a QC gearset at the back so I can change gears for street and open road racing.
 
Not only that,, but since I am seeing that the Transaxle is sequential, are they straight or helical cut gears. I'm not sure if I have seen a helical cut sequential gearbox for cars.

No reason you can't have helical gears with a sequential, but no one really expects a sequential to be a daily driver. So not much call for helical.

Can you imagine the valet trying to park your sequential dogbox?
 
A valet trying to park your SLC is bad enough...lol

It would be weird to push in the clutch and just bump the shifter up or down. Guess if you were creative,, and have an "automatic" clutch system put in. I think the problem would be the shifts could be done so fast,, the engine/transmission would not have time to "sync up"
 
I've been in a couple spots where I had to let the valet park my Freightliner.

About half jumped in the cab and immediately jumped out and asked me to park it. The other half I just reiterated numerous times YOU HAVE TO PULL THE BIG YELLOW BUTTON TO PARK. And then I walked inside so I did not have to watch. ;)
 
Holinger is straight cut only, which would work for racing, but not ideal for street use,, as I know of know way to stop the whine on a dog-box.
 
Have a talk to Leon , the trans axle he's doing has top loader internals, so can be either a dog, IE Jerico, or syncro helical.

cheers Kaspa
 
I looked very hard at the T56 and the T6060 for my gearbox guts.

It is all about packaging. In a GT40 the rear of the car would not contain the 850QC gearbox, (27.5" plus bell housing 5.375) so it has to be smaller than that.

The T56 Gear stack is to long. 17.5 inches. Add a 10 inch Diff housing and a 4.5" bellhousing. The T56 gear stack dose not have the ratios that will allow the power to be brought in on the cluster shaft. so that will require a set of drop gears or quick change gears or BOTH. This will require 4 inches or more of space that we do not have. :thumbsdown:

TOTAL Stack (inline) will not be shorter than 36". 4" longer than a Recardo

I almost forgot, you will still need to support the pinion. :thumbsdown:

More than anyone here I wish it would work, but the space in the car will not allow for it.
 
Some modern transaxles put the R&P along side the gear stack. The TKO gear stack is roughly 14". With QC gears, drop gears and a 10" R&P [and pinion support ;)] and oil pump, my transaxle is about 24" from bell housing to tail.

So a T56 may be doable in 27".

As you say, it's all about packaging. This is trading width for length. There is no free ride...
 
Mine, the patterns of which have now progressed a long way from this old pic is 29" WITH the bell housing, or 24.5" from the bell housing. It can be 5 speed within those measurements as well if I wish, but I am aiming to make it as much like a T44 as possible. It has pinion support.

Ryan if you look at pics of MKII cars you will notice that the pump on T44 sticks out just past rear panel, so assuming half shafts are close to rear axle centerline its the distance from half shafts to rear of TA case that is critical. This transaxle is going to have an FE up front which is a bit longer than Windsor.
Tape measure in pic if you can enlarge for reading shows a distance of 19.25 from rear axle to rear of trans, though you could fudge that a bit within CV/U-Joint limits.
 

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I also suspect that most any GT40 does not need a 6 speed. With light weight and high HP, it is a PITA if the gears are close together. Or course, most street cars need a good overdrive for highway usage. Jac Mac's trans will obviously fit a GT40, so with a 5th suitable for a person's planned use (street or track), it could be ideal.
 
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