I've been on the hunt for an F40 trans that has the 2007 gearset. I found one on ebay that they listed as "2006-2007". I contact the seller and asked them if they knew which gearset it was, they said they didn't - they had gotten a bunch of them from a GM Auction, but would be happy to check if I could tell them what numbers/stamp would indicate it.

On the flipside, found another place that had 9 F40s that they had marked clearly as 2007, I contacted them and they said "They are new, manufactured in 2007, but still have the 2006 gearset."

I emailed them back and asked them what to check to identify the gearset, but I haven't heard back yet.

Any thoughts would be greatly appreciated. Thank you!

Oh! And that second place were selling those F40s very inexpensively. I think if I bought them all I could probably get them to cut me a deal... but do you guys think they'd be worth trying to "flip", or do you think anyone who needs one of these (Fiero guys, G6 guys, Saab, whatever) is going to be hunting for the better gearset as well?

Thanks!

there was another thread about this as well I think that they are all the same gear set. the only one that was differant was the F40 for the Sabb that wil not work for our cars.
but just to make sure do a search for F40
D.

Heya Whodeanie,

I've done plenty of reading up on it here, trust me. Enough to make my head spin (and trying to spin the heads of others... just ask Will). They did a gear change in 2007.. here's the summary on it:

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.

So now it's just a matter of making sure I get the right one!

Maybe this will help....

https://www.fiero.nl/forum/Forum4/HTML/046878.html

Sorry if you have already looked here....

------------------
Paul

My IMSA Build: http://www.cardomain.com/ride/789315
HHP Adjustable Sway Bars: https://www.fiero.nl/forum/Forum4/HTML/036556.html

Hey Runner!

Thanks for the link, yes I had seen it, but I didn't catch if there was a way to tell outside of the physical differences. I suppose I can take the pictures and send them off to sellers who aren't sure. -- I'll re-read that thread though, just in case someone did put down a model or ID number and I missed it!

Thanks again for the replies!

I got ya, I have an 06 for mine but with a LS3 I dont think a little gear change will make that much differance to me.
looking over the pic's the only thing I can see that stands out to me. it looks like they did away with the counter balance arm on the shift liknage.
and I can say that one of the stickers on mine has MT2 on it so maybe they did the same for the MU9
D.

http://i544.photobucket.com...onto/0607compare.jpg

'05 is the only year for the gearing you want with a healthy V8.

Hey Isolde,
**Edited info here** I tried doing a search for the 05 G6 F40s... it seems that they only at automatics for that year? At least that's what car-part.com is telling me when I want to do a search. Are you sure you meant 05? **Edit*

Do you by chance know what the gears were for that year? I'm talking with Houseman in Canada about reworking some of the gears, but obviously the less they have to change, the less expensive it is.

Will had suggested first gear at 2.5 and 2 at 1.85, keep the 3-5 gears from the 2007 model, and then put in the final drive gear from an 06. (unsurprisingly, the final drive gear change by itself is actually fairly inexpensive. The rest of it gets pricey because they need to basically remanufacture things.)

Also, there seems to be alot of conflicting info on if the 07 and the 06 have the same bolt pattern. I guess I can stop in a stealership and ask them if that's the case, but I doubt alot of them will have both of those transmissions just sitting around on hand.

But if the 05 is more ideal... and has the right bolt pattern, then there's no worries! lol

Looking forward to hearing more from you, Isolde!

[This message has been edited by Trinten (edited 07-23-2009).]

None of the F40s have a good first gear, and you're right, a decent first then needs a better second, but a 2.5:1 first, with a 3.54545:1 final is a bit tall for most F40-equipped fieros, since most of them are 3.8s or 4.9s, we need gears that'll be okay for everyone. I've been working with a local business to build me a 2.98:1 first, to go with my 2.0400:1 second, 1.3208:1 third, 0.9538:1 fourth, 0.7547:1 fifth and 0.6230:1 sixth. But on paper, that's still not great. Will's proposal isn't bad, but won't give as tall a sixth as my efforts, and I'd like my sixth to be even taller. I could drop another 300 rpm at 65 mph, and even the 3.8s could do with 200 less, even assuming a 26.7" tire such as a 245/45R18. But the cost of a new second gear is too much to justify the slight benefit of such a small change in ratio, to something around 1.9:1. Besides, keeping second at 2.0400:1 makes it more useful when taking a tight right that you don't have to completely stop for. I like the third gear in the later F40s, but I doubt I can cherry-pick like that. taking third and fourth would be great for my twin turbo LS6 combo at the dragstrip, but on the street, that won't truly matter. Still, going with will's proposal will cost you clutch life in stop and go traffic, and 2 mpg highway driving with an engine as large as mine (5.7L)

Hey Isolde,

Thanks for the info again. I've got a 350 myself, so we're about in the same boat. Since I drive the car so infrequently I'm not *too* worried about clutch wear (please note I didn't say I'm not worried at all, but since I put on less than 3k miles in a year...)

Now you mentioned "2 mpg highway".... are you saying that'd happen with the 3.55 final drive? I've got the stock 15 inch GT wheels, doing 70mph right now I'm turning about 2800 RPM (4 speed muncie), so anything lower than that would be an improvement.

Essentially 5th and 6th will be there for highway driving... they said changing out the final gear is pretty easy (they were able to quote me immediately for that), so what would you recommend for a 6th gear for good mileage?

From what Will had told me, there are obviously limitations on gear sizes just because of the physical dimensions of the transmissions, but I can run all the ideas past Houseman and see what they come up with.

Thanks again!

I've owned/modified/driven dozens of camaros with 5.7L V8s, of all diferent years, and in every case I've experimented with the gearing. It's something I can't lose interest in. And from that, my own conclusion is that it does little good to gear a carbureted 350 to run at less than about 1750 rpm at 65 mph, unless it's a computer-controlled Q-Jet that's freshly rebuilt, and you're running a stock "929" cam. But the LS1 is perfectly happy cruising along at 1450 rpm at 65 mph, where it will return 31 mpg. But that's with the T56 and stock 3.42:1 gears. If you replace those with 4.10:1 gears, you lose 2 mpg, minimum. So, if I did change my F40's sixth to something closer to 0.50:1, I could expect another 1.5-2 mpg. I suppose the TPI 350 in stock late-'80s cOrvette form was also capable of 1450, but I never drove that setup. The LT1 in my '95 Z28 was okay at 1600, but 1800 was better. I could give more examples, but it gets redundant. In case you don't have it handy, the formula for finding rpm, using the tire diameters listed on tirerack.com, is gear ratio in the trans, times gear ratio of the differential, times the constant 336 times mph, divided by tire diameter. If your 350 has a more serious cam, something like a COMP XE268, then it'll feel better running over 2000 at 65. More cam, more rpm holds true for any engine.

Thanks again! That's more info I wasn't aware of. I'd take 1400s over nearly 3000 on the highway any day of the week!

Eventually the car will be running a fuel injected setup (right now hoping to have that done within the next 6 months. Want to get the engine done first, followed by transmission, exhaust, then EFI conversion). Still working out the details (waiting to hear back from two different businesses to make a final decision on the specifics). It will be running a wilder cam... if I remember right (doing a quick glance at comp cams) it'd be either a 268 XFI HR13 or the 280 XFI HR13.


I don't think I'd ever want something as "tall" as a 4.10. My room mate has 3.73s in his 94 TBird (which is a reasonably big car) and it has some serious grunt to it, so I'd be pretty happy with the 3.55 -- besides, I think if I change that 3.55 around, then the Quaife LSD I want won't work... assuming I correctly understand anything about how a transaxle is put together, which I admit I might not.

quote Originally posted by Isolde: None of the F40s have a good first gear, and you're right, a decent first then needs a better second, but a 2.5:1 first, with a 3.54545:1 final is a bit tall for most F40-equipped fieros, since most of them are 3.8s or 4.9s, we need gears that'll be okay for everyone. I've been working with a local business to build me a 2.98:1 first, to go with my 2.0400:1 second, 1.3208:1 third, 0.9538:1 fourth, 0.7547:1 fifth and 0.6230:1 sixth. But on paper, that's still not great. Will's proposal isn't bad, but won't give as tall a sixth as my efforts, and I'd like my sixth to be even taller. I could drop another 300 rpm at 65 mph, and even the 3.8s could do with 200 less, even assuming a 26.7" tire such as a 245/45R18. But the cost of a new second gear is too much to justify the slight benefit of such a small change in ratio, to something around 1.9:1. Besides, keeping second at 2.0400:1 makes it more useful when taking a tight right that you don't have to completely stop for. I like the third gear in the later F40s, but I doubt I can cherry-pick like that. taking third and fourth would be great for my twin turbo LS6 combo at the dragstrip, but on the street, that won't truly matter. Still, going with will's proposal will cost you clutch life in stop and go traffic, and 2 mpg highway driving with an engine as large as mine (5.7L)

considering that the stock automatic gears are generally TALLER on 4.9 AND 3800SC, typically 2.97, 2.83, or 2.73 final and and 2.92 1st gear, i dont think 3.55 and 2.5 would be too bad with a 4.9L or a 3800SC...if anyone gets those gears produced, i want in...

stickpony, keep in mind that because of the torque converter, less gear is needed. The converter multiplies engine torque by 1.6:1-3:1 at stall rpm with the car not moving, and except when locked while cruising down the interstate, is always slipping at least 200 rp, and usually closer to 400.

quote Originally posted by stickpony: considering that the stock automatic gears are generally TALLER on 4.9 AND 3800SC, typically 2.97, 2.83, or 2.73 final and and 2.92 1st gear, i dont think 3.55 and 2.5 would be too bad with a 4.9L or a 3800SC...if anyone gets those gears produced, i want in...

My C4 4+3 vette had a 2.88 1st gear and a 3.08:1 final drive and with a TPI 350 seemed just about right and wheel spin was just a throttle input away.

He quoted me 1875 USD (their in Canada) for the final drive set, with optional REM polishing and local cryotreating (additional cost, of course). When I spoke to him on the phone about any other strength boosting services, he said they also offer shot-peening, again, additional charge.

quote Originally posted by Isolde: stickpony, keep in mind that because of the torque converter, less gear is needed. The converter multiplies engine torque by 1.6:1-3:1 at stall rpm with the car not moving, and except when locked while cruising down the interstate, is always slipping at least 200 rp, and usually closer to 400.

true, but there isnt that much of a disparity. the 4.9L and the 3800SC both are low end rpm TQ monsters in stock form. tall gears dont bother them in the slightest. i have an econo 4 speed hooked up to mine, with is 3.53x3.32=11.71 when you are in 1st gear, and 1st gear is over before i can blink(almost useless). a stock deville tranny is 2.92x2.73=7.97 in 1st gear, and even though the TQ converter assists, it is still a very tall 1st gear, and the 4.9L handles it like it is a knife cutting a stick of butter. 3.55x2.5=8.87 would be a favorable 1st gear on a manual tranny mated to a V8 or 3800SC, IMO, ESPECIALLY if any mods were made to the engine(s) in question....

just my 2.5 cents

8.867:1 with a manual does not compare to 8.87:1 with a stick. Yes, all 94-02 Z28s with the T56 came with a 9.08:1, but noone argues that the popular 4.10:1 gear swap helps driveability and isn't too much, with their 25.7" tires. The T56 in question uses a 2.66:1 first. As for just changing first, read Trinten's other thread.

quote Originally posted by stickpony: so basically 1900 to change out the final drive ehh? did he give you gearing options or was it entirely up to you? what if we just want 1st gear changed? how much for just 1st gear?

We didn't get into gear options for the final drive as it wasn't what I was looking to do. That's just the first thing he told me when I asked him "Can you change the gears on a F40?"

My other thread on the progress (or lack there-of) of getting the first and second gear work done can be found here - https://www.fiero.nl/forum/Forum2/HTML/102226.html

Essentially it all depends on how the gears are designed and how much "Re-manufacturing" (as he put it) needs to be done. He didn't even want to give me a ballpark since he has not seen these gears in person yet, which is why he requested some technical drawings so he could quote me properly.

Isolde has very generously offered to help track down the documentation I need.