6 speed gearset for ST165/185/205

[wagonist]

Final drive, on our boxes, is the CENTER diff ratio..
so changing it you don't need to change anything else...

Ah thanks. Make sense now.

Toyota EPC of gearset layout for ST215 Caldina
Toyota EPC of gearset layout for ST205 Celica
I was having a look at this while trying to understand the Final gear thing.

From the looks of the gear layout, it goes:
1st ... reverse ... 2nd ... 3rd ... 4th ... 5th

I can't quite understand the synchro layout, but it looks like 5th has its own syncho on the end of the shaft.
This could possibly be utilitied by putting a 6th on the other side of this synchro & using a double sided one, like those used for 3rd/4th.

CLG, how are the linkages laid out for the ZE 6 speed? Normally there are only 3 planes (1st/2nd, 3rd/4th, 5th/rev) with 3 shafts, but with an extra gear .

[Bill Strong]

Why don't you just adapt up the Saab F40 6-speed? It comes in two flavours, FWD and AWD.
It is good for over 400nm of torque. It also weighs less than the MR2/GT4 transaxle.
This is the transaxle that Cbulen and I are using on our V8 MR2s.

Just a thought.

[Bill Strong]

2008 F40 (MU9)
General Motors Powertrain-Europe F40 six-speed manual car transaxle
2008 Model Year Summary

Carryover Features and Benefits from 2007 model year

DETENT SYSTEM FOR QUICKER AND EASIER SHIFTING
The addition of a ball-and-spring-type detent on the shift sleeve and detents on the shift rail assists the driver in shifting quicker. The detent raises the force required to move the shift lever which prevents excess movement of the shifter by the driver, and reduces the chance of double bump. Tension between the shift sleeve and the shift rail also prevents the sleeve from vibrating while in gear.

GEAR RATIO CHANGES FOR QUICKER ACCELERATION
To adapt the F40 to North American applications and maximize performance, 3rd through 6th gears have been changed to higher-ratio gears starting in 2007 model year. The ratio for 3rd gear is now 1.37:1, and the ratio for 4th gear is no longer an overdrive, with a new ratio of 1.05:1. The 5th gear ratio is 0.85:1 and the 6th gear ratio is 0.71:1.

LOW MAINTENANCE

The MT2/MU9 uses a Castrol Burmah (BOT 0063) manual transmission fluid, and is validated as "fill-for-life". No maintenance is required for normal operation.

OVERVIEW

Originally a design developed for Fiat, Opel and Saab applications, the F40 (MT2) is a GM Powertrain - Europe six-speed manual transaxle built in Russelsheim, Germany. Its first use in a North American application was the Pontiac G6 for the 2006 model year. It is also used in some Saab 9-3 and 9-5 models.

It is a three-axis design, with first, second, fifth, and sixth gears on an output shaft behind and below the input shaft, and third and fourth gears are on an output shaft in front of and above the input shaft. Both output shaft pinions drive a helical gear with a conventional differential. The clutch is mounted on a dual-mass flywheel to dampen vibrations on whichever output shaft is idle depending upon which gear is selected.

The F40 is cast in aluminum, and weighs 124 pounds (see specs). It has been certified for up to 400 Nm of engine torque.

Triple-cone synchronizers are used on 1st and 2nd gears. These synchronizers have three friction surfaces, which increase their ability to transfer the flow of torque more smoothly from one gear to another. Synchronizers act as clutches to speed up or slow down the gearsets that are being shifted to, and greater friction area results in easier shifting for the driver. The 3rd, 4th, and reverse synchronizers are double-cone, while the 5th and 6th gear synchronizers are single-cone. All of the friction surfaces on the synchronizer rings are sintered bronze. The ratios in the 6-speed are widely spaced for versatile performance and efficiency.

transmission information:
F40 transmission (MT2 or MU9) only difference is gear ratios:

2006 F40 (MT2)
Type: transverse front wheel drive, six
speed manual transaxle
Engine range: 3.9L
Maximum engine torque: 245 lb-ft ( 333 Nm )
Maximum gearbox torque: 295 lb-ft ( 400 Nm )
Gear ratios: MT2
First: 3.77
Second: 2.04
Third: 1.32
Fourth: 0.95
Fifth: 0.76
Sixth: 0.62
Reverse: 3.54
Final Drive 3.55
Maximum validated gross vehicle weight: 3527 lb ( 1600 kg )
Case material: aluminum
Center distance: 197 mm
Fluid type: Castrol BOT 0063
Transmission weight: 56 kg ( 123.5 lb )
Fluid capacity (approximate): 3.1L / 3.27 qt ( dry )
Power take off: no
Applications: Pontiac G6

2007 GME Germany F40 ( MU9 ) 04/04/06
Type: transverse front wheel drive, six-speed manual transaxle
Engine range: GM 3.9L V6 ( LZ9 )
Maximum engine torque: 245 lb-ft ( 333 Nm)
Maximum gearbox torque: 295 lb-ft ( 400 Nm )
Gear ratios: MU9
First: 3.769
Second: 2.040
Third: 1.365
Fourth: 1.048
Fifth: 0.846
Sixth: 0.707
Reverse: 3.538
Final Drive Ratio: 3.55
Maximum validated gross vehicle weight: 3527 lb ( 1600 kg )
Case material: aluminum
Center distance: 197 mm
Fluid type: Castrol BOT 0063
Transmission weight: wet: 56 kg ( 123.5 lb )
Fluid capacity (approximate): 3.1L / 3.27 qt. ( dry )
Power take off: no
Applications: Pontiac G6

2009 GME F40-6 ( MK6 ) AWD 06/09/08
Type: transverse all wheel drive, six-speed manual transaxle
Engine range: GM 2.8L V-6 Turbo ( LP9 )
Maximum engine torque: 295 lb-ft ( 400 Nm)
Maximum gearbox torque: 295 lb-ft ( 400 Nm )
Gear ratios: MK6
First: 3.917
Second: 2.040
Third: 1.365
Fourth: 1.048
Fifth: 0.846
Sixth: 0.740
Reverse: 3.750
Final Drive Ratio: 3.762
Maximum validated gross vehicle weight: 5423 lb ( 2460 kg )
Case material: aluminum
Center distance: 197 mm
Fluid type: Castrol BOT 402
Transmission weight: wet: 56.5 kg ( 125 lb )
Fluid capacity (approximate): 1.8L / 1.9 qt. ( dry )
Power take off: no
Applications: Saab 9-3

[Bill Strong]

Here is an awd version on the USA EBay

http://cgi.ebay.com/ebaymotors/09-Sa...#ht_500wt_1448

[oldcorollas]

56kg? damn!

[wagonist]

2009 GME F40-6 ( MK6 ) AWD 06/09/08
Type: transverse all wheel drive, six-speed manual transaxle
Engine range: GM 2.8L V-6 Turbo ( LP9 )
Maximum engine torque: 295 lb-ft ( 400 Nm)
Maximum gearbox torque: 295 lb-ft ( 400 Nm )
Gear ratios: MK6
First: 3.917
Second: 2.040
Third: 1.365
Fourth: 1.048
Fifth: 0.846
Sixth: 0.740
Reverse: 3.750
Final Drive Ratio: 3.762
Maximum validated gross vehicle weight: 5423 lb ( 2460 kg )
Case material: aluminum
Center distance: 197 mm
Fluid type: Castrol BOT 402
Transmission weight: wet: 56.5 kg ( 125 lb )
Fluid capacity (approximate): 1.8L / 1.9 qt. ( dry )
Power take off: no
Applications: Saab 9-3

Kudos for thinking outside the square, but this poses quite a few extra problems.
1. what is the front/rear split of the centre diff? Not all are 50:50
2. what is the front diff ratio? If it doesn't match our rear diffs, then that will require changing.
3. at what angle does the rear housing face, and at what height? There isn't much room for at the front of the transmission tunnel.
4. If this is the same box that GM used in the 90s, then it will be absolutely bulletproof when used in a 2wd application like your MR2, but they were absolutely hopeless in 4wd form as used in the Holden/Opel/Vauxhall Calibra turbo 4x4. They used to blow apart the centre diff even with stock power.

[Bill Strong]

ya, I have one sitting in my dinning room. It is not as light as a C-series, but hugely less than the GT4 transaxle I have connected to my 3SGTE.

and remember that these transaxles are rated at a weight of 1600kg. since the GT4 weighs much less than that, you are looking at the transaxle handling much more torque.

[wagonist]

56kg? damn!

Sheesh, I missed that one.
I know the Toyota box is heavy, but it is liftable.

And I forgot about now having to modify 3 engine mounts, plus front driveshafts, plus a tailshaft, plus shifting linkages/cables, plus gearbox/engine interface.

Changing a gearset starts to look a lot more attractive.

Out of curiousity, how difficult would it be to just get certain gears made up? ie if I just wanted the 5th changed so it was taller. And both halves of this are splined onto the shaft.

[Bill Strong]

Iquaife does a lsd as well.
http://www.quaife.co.uk/Saab-GM-F40-...B-differential

I doubt this is the same gearset, but you never know. 800+hp awd Saab.
http://www.youtube.com/watch?v=abTnQ-N4WNk

This is the new GM box. Not even close to the old box like used in the Calibra (still one of my favorite cars I had while living in England).

[wagonist]

ya, I have one sitting in my dinning room. It is not as light as a C-series, but hugely less than the GT4 transaxle I have connected to my 3SGTE.

and remember that these transaxles are rated at a weight of 1600kg. since the GT4 weighs much less than that, you are looking at the transaxle handling much more torque.

ST205 maybe, but the ST185 comes in at close to 1400kg, and my Caldina weighs 1470kg empty. So add 5 people (at a squeeze), their luggage, plus anything extra on the factory roofracks, and you can safely say that the 1600kg is blown out of the water.
And then there's the towbar I want to fit so I can tow my race car around (add another 1200kg)

[Bill Strong]

TRD and Quaife have done gearsets for the cars over the years. The main issue is cost. We looked at having a new 5.0:1 final drive made up for our C-series AW11 box and the cost was a bit over us$5000 (machined in Canada). If you had a few thousand made that would have seriously reduced the cost.

Cost for the C-Series close ratio gear sets are around us$3000. since they don't make them for the GT4 / SW20, you could probably look at twice that cost, maybe 3 times depending on the cost of the material and machine costs.

[Bill Strong]

would not having a quaife 5 / 6 / 7 speed box made be a better solution?
There would be no compromises as what you would have to do with converting a production box. The last time I checked the Quaife box started at us$35,000 (std close ration 5-speed), of course once you started adding all the cool stuff you were closer to us$150,000.

I really think the F40 would be a good solution for those that want a lighter AWD 6-speed transaxle, but yes, it will take a fair bit of modification to work.
On the issue of the rear diff, maybe even convert to the Saab rear differential. You are looking at cars that are about equal in weight and stock power, though I think the Saab has a wider torque range.

Just my 2 cents.

I am using the F40 with a GM Northstar V8 that is running at close to 375hp with about the same torque at the flywheel in a AW11. Guys also been using this transaxle in V8 Pontiac Fieros for the past few years with very good success. The weak link has been axles, but I have found that modified Honda Integra axles should work quite well, some racing axles are rated at over 1000hp, so they should hold up well in my application.

[Bill Strong]

Can't tell if it is offset in the chassis. It sorta looks like it. But nothing you can't engineer to fix.

[Bill Strong]

looks like the diffs are electronically controlled. may be a bit more than most people can do as DIY'ers. But, you could use an aftermarket electronic tranny controller linked into the ABS circuits to control lockup.

Restyled to show off the bold look of the Aero X concept, the new 9-3 is actually more new than you might think. Saab told us that many of the components are all-new or upgraded—bodywork forward of the A-pillar is fresh, plus updates on all lights and both bumpers. It’s available as a sedan, convertible or Combi (station wagon for us ‘Murricans), but the biggest news is that Saab’s finally getting with all-wheel drive.

Later this year, we’ll get what Saab is calling XWD (cross-wheel drive), which is actually the latest generation all-wheel-drive system from European AWD specialty firm Haldex—the same company that produces the system for Saab’s Swedish rival, Volvo. Many cars have traction control and some sort of active AWD system, but XWD uses computer-controlled center and rear differentials to apply power to the opposite corner of the car from the wheel that loses traction. The genius is that the system does all this in 80 milliseconds, long before the rear wheel on the low-grip side even hits the icy patch. It sounds impressive on paper, but even the brief demo we experienced on a grassy field in suburban D.C. was compelling. Grip was immediate and highly controllable, as well as completely transparent and absent of any buzzing, abrupt changes in attitude or intrusive braking from the stability control system. Nice.

The other news is under the hood: Saab’s 2.8-liter turbo V6 engine has been uprated by 15 percent to deliver 280 hp and 295 lb.-ft. of torque on XWD models, achieved largely by increasing the turbo boost from a maximum of 7.5 to 9 psi. All of this is delivered to the wheels through a six-speed manual or six-speed auto transmission with Sport mode manual gear selection. There’s also a more fuel thrifty 2.0-liter four cylinder that makes 210 hp and 221 lb.-ft. And that combo is actually fairly zippy as well.

There’s plenty of other cool stuff on the ‘08 Saab 9-3, such as headlights that swivel to follow the front wheels in turns, a killer Bose stereo and rain-sensing wipers. We’ll take a turbo Combi... for impressing all those soccer moms at the local Safeway supermarket. —Mike Allen

[wagonist]

Iquaife does a lsd as well.
http://www.quaife.co.uk/Saab-GM-F40-...B-differential

I doubt this is the same gearset, but you never know. 800+hp awd Saab.
http://www.youtube.com/watch?v=abTnQ-N4WNk

This is the new GM box. Not even close to the old box like used in the Calibra (still one of my favorite cars I had while living in England).

I just remembered that box was the F20.