six speed
Trans Name First Second Third Fourth Fifth Sixth

MR6 Opel F40 WR 83mm 3.917 2.040 1.321 0.755 0.623 0.623
MT2 Opel F40 83mm 3.77 2.04 1.37 1.05 0.85 0.62
MU9 Opel F40 83mm 3.77 2.04 1.37 1.05 0.85 0.62
five speed
MU3 Saab F25 3.48 1.76 1.18 0.89 0.70



FDF Germany F35 — 5-speed transverse manual made by FDF Germany

e F35 features a two-axis conventional transverse layout, with fully synchronized gears, and compact packaging. It features a higher torque carrying capacity than most manual transaxles currently in use by competing North American small cars.
Design features include triple-cone synchronizers on 1st and 2nd gears, and single-cone synchronizers for 3rd, 4th, 5th and reverse gears.
Specifications[edit]
It weighs approximately 99 lb/45 kg and uses 2 quarts/1,9 l of GM 88862472 gear oil. This gear oil is identified in GM documentation as a synthetic 75W-85 GL-4, Castrol Burmah (BOT 0063) manual transmission fluid, and is validated as "fill-for-life". No maintenance is required for normal operation. The gearbox is rated for 260 ft-lb (353 Nm) of engine torque.
The GM transmissions are usually numerically designated in newton metres that means F35 is rated at 350 Nm, the weaker rod shifted SAAB version of the F35, the F25, at 250 Nm, F40 at 400 Nm, M32 at 320 Nm, and so on.
Differential[edit]
A limited-slip differential is available for high-output applications. GM has sourced Quaife's automatic torque biasing (ATB) torque-sensing (Torsen-style) differential, which is an all-mechanical geared unit that uses no clutch packs or preloading to transfer torque from one axle to the other. The torque transfer occurs automatically and gradually when one wheel loses traction. This type of differential can severely reduce the effects of torque-steer.

FGP Germany F40 — 6-speed transverse manual made by FGP Germany


The GM F40 six-speed manual transaxle was first developed for Fiat, Opel, and Saab applications and is built in Russelsheim, Germany. The first North American application was the 2006 Pontiac G6 as well as certain Saab 9-3 and 9-5 models.
The F40 has 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.
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.
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.
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.
The F40 is cast in aluminum, and weighs 124 pounds (56.2 kg). It has been certified for up to 295 ft-lb ( 400 Nm) of engine torque.
The F40 MT2/MU9 uses a Castrol Burmah (BOT 0063) manual transmission fluid, or GM 88862472 gear oil. This gear oil is identified in GM documentation as a synthetic 75W-85 GL-4. No maintenance is required for normal operation.

 

Biggest thing I see? No lsd in an F40/ that ends it for me.

 

No LSD is a bummer, one of the draw backs. One can be installed, but you are looking at more $$$ on already ~4k swap.

 

If it were me.. i would go 4.45 F35 LSD. However 4.45 gears are becoming a rarity. F40 isnt bad though. Best of luck OP.

 

lol I did. 2004 we built a bunch. For years I had 4.45 's I ran one, and no one wanted them. Now, POOF almost all the gears are gone. funny world.

 

If I ever break mine thats the route Ill go. Fingers crossed though.

 

You would go three tenths or more qwiker ET in the 1320 i bet

 

FMSR offers the F40 with the LSD but it's expensive.
What worries me is that the F35 is rated for 350Nm which is only ~260 ftlbs.
Does the 4.45 conversion increase the torque rating or reduce the stress on the components?

 

Its been shown to handle way more than 260. It just doesnt like 400 at low RPMS in third

 

4.45 much reduces stress on tranny. Think of the pressure you put on your bicycles peddles in 1st gear vs 24th gear from a stop.

 

FMSR offers a f35 rated for all different power levels.

 

I am not sure what Rudy does for the 999 option to make it better but it comes out to over 3,588 shipped for a used rebuilt, and 1780.00 more for a new transmission ; both with 4.45 gears (590.00 ) and includes shipping. 5368 shipped for a new trans.

I am also not sure where the new gears come from, as the stock at GM is gone and done. An LSD new trans from GM runs 4000.00 3.82 or 4.05 the only ratios available, includes LSD. plus shipping

Maybe Rudy can chime in here and tell us what the $999 option does for the F35 to make it better...


Certainly the reviews on his web site are very favorable.

 

And boom goes the dynamite

 

John what's the cost of your trans with 4.45, really considering dropping a new one over winter, thanks!

 

cant say all our 4.45 gears are sold as of today. normally we do 1900 exchange rebuilt assuming your core trans is useable, for a 4.45 lsd trans.plus shipping.

I have a plan working on it to resolve the 4.45 crown wheel issue, but thats just going to put another 6 to 12 cwp in the system. Making a 4.45 pinion for the cwp would cost more than the trans.

Oh and a brand new trans is 4000 like I said, plus about a grand to 4.45 it; most of that is labor to strip and rebuild in order to change the cwp; plus shipping

 

Never realized how expensive transmissions are for this car, makes me never want a upgraded turbo.

 

What would you consider low rpms my turbo spools around 3k . Wouldn't be cruisin. In 3rd then just floor it I would downshift....I ask to get a lil more oversight on what causes them to.go, I'm turbo swapped already.
Man you said it but I'm already dedicated and addicted.to the power.

 

The F23 can hold more power than it should in most cases, the 230 rating doesn't mean much, I talked to someone with a turbo cavy and was about 380 wheel and he did go through one transmission and the second didn't give him any troubles. I should also mention that the transmission that went had about 240k miles on it.

 

And some f23s came factory with a 4.41 FD so its only a few hundred for a low geared tranny versus an f35

 

I plan to try out the f23 one day

 

I love my 4.45. It basically eliminated 3rd gear from the equation road racing. I stay in 4th and 5th all day . At 6600 rpm in 4th gear Im at 131 MPH and its hard to watch the speedo in fifth Ha Ha

I work with John finding parts for these trans and its not easy.

 

whenever your turbo spikes torque hardest. its just too much on third in those 3.82 F35s Downshifting saves transmissions!

 

My local track is relatively slow; I'm in 3rd gear for 80% of it. Only (2) 2nd gear turns and only get to 4th on the straight. Takes me about 2:10 for 2.2 miles so roughly 60mph average...

 

Why did GM choose to put the 3.82 FD in the Cobalt LNF, but put the 4.05 in the LSJ and HHR LNF?

 

More economical and a longer gear for cruising is probably why they did it. Also helps with the longer pull that a turbo has compared to the down low torque an sc has.

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