Which gears for an auto? - 2003-04 Mach 1 Registry Owners Club

Skymack · 11-24-2013, 09:10 PM

I have an '04 automatic Mach 1 and the previous owner told me that he put 3.27 gears in it. Do you guys think I should change the gears? I'm thinking about either 3.73 or 4.10's. I mainly drive open roads with little city driving. I don't plan on adding any FI. Also, what else do I need to buy besides the gears themselves for the install? I would have a shop install them for me.

I know there's a ton of threads on gears, but most are regarding manual trans. and hardly any compare 3.27's.
Thanks!

SuperMach1 · 11-24-2013, 09:22 PM

What are your plans with the car? Is it a daily driver? I have an auto with 4:10's but thinking if putting some 4:30's in. If your car is a dd I would go with 4:10.

FOURCAMS · 11-24-2013, 10:05 PM

I'm in the same boat with my auto, was looking at 3.90's now almost set on 4.10s

Skymack · 11-24-2013, 10:07 PM

It's my daily driver. Sorry, I forgot to mention it. I plan on getting gears then probably getting a dyno tune. I really doubt I'll ever take it to the track.

stellasmechanic · 11-25-2013, 12:06 AM

If you don't care about gas mileage, 4.10 or 4.30 would be my choice. Have had three auto cars (guess four with my latest).

I started out at 4.30 and was okay except for the highway at 80 mph was a little high on RPM for me. 4.10 would have been perfect.

I'm at 4.56 now but only see about 2k street miles a year. Screams on the highway but sure is fun to drive. Requires good tires though.

If you care about gas mileage, 3.73's or 3.90 would be my thought. Gears kill gas mileage pretty quick going from 3.27 to 4.10 especially on the highway.

My .02 for what it's worth.

Mustang9668 · 11-25-2013, 12:07 AM

I've been daily driving my mach with 4.10s for a year now with no regrets. I still can get 20+ mpg highway with no problems.

Sent from my SCH-I535 using Tapatalk

Skymack · 11-25-2013, 12:23 AM

I'm not going to go above 4.10's. I'm torn between 3.73 and 4.10's. I'm leaning more towards 3.73 because of the gas mileage.
My car pulls pretty hard with the 3.27's (chirps tires going into 2nd). Will going to 3.73 make a big difference in acceleration?

stellasmechanic · 11-25-2013, 01:28 AM

Quote:

Originally Posted by Skymack

I'm not going to go above 4.10's. I'm torn between 3.73 and 4.10's. I'm leaning more towards 3.73 because of the gas mileage.
My car pulls pretty hard with the 3.27's (chirps tires going into 2nd). Will going to 3.73 make a big difference in acceleration?

It will be noticable enough to enjoy. 3.73 is a good compromise since you do mostly highway driving.

We always want more gear, no one wants to get 13 MPG though (me).

Skymack · 11-25-2013, 09:14 PM

Thanks guys!

I'm thinking about ordering this:
http://www.latemodelrestoration.com/...r-End-Gear-Kit

Is that everything I would need if I had a shop install them?

I know my speedo will be off and you can use a tuner to recalibrate it, but is there any way to recalibrate it without using a tuner? I have an SCT handheld tuner, but it makes my exhaust quieter and after hearing the horror stories from them screwing up A/F ratios I got nervous about it and took it off.

Mach828 · 11-25-2013, 09:59 PM

Go with the 4.10s!

That kit has everything you'd need.

Use the SCT. Get a good dyno tune!

Sent with a shot of DROID go fast

Skymack · 11-25-2013, 11:19 PM

Quote:

Originally Posted by Mach828

Go with the 4.10s!

That kit has everything you'd need.

Use the SCT. Get a good dyno tune!

Sent with a shot of DROID go fast

Why 4.10s over 3.73s? I think 3.73 will be a better choice since it's my daily driver and it won't impact my gas mileage as much as 4.10s will.

Mach828 · 11-25-2013, 11:41 PM

Im not the one to be asking on going conservative with gears. I've got a supercharged mach with 4.56 gears and a lower overdrive transmission than stock.

I just think 3.73s will barely be a difference. You won't see the drop in the city but you will in the freeway.

Sent with a shot of DROID go fast

Mach828 · 11-25-2013, 11:48 PM

Here are the rpms for each at 75. 26" stock tire. Auto overdrive is .698

3.27 - 2,200
3.73 - 2,500
4.10 - 2,700

Sent with a shot of DROID go fast

Fosters · 12-04-2013, 12:58 PM

I have 4.56s in my marauder, though that's on a 29" tire, so it's about as 4.10s would feel in a mach. They are much more fun than the 3.55s it came with stock, but not quite as fun as the 4.56s I had in the mach with the t56. There's very little difference between 4.10 and 4.30; if you don't care about getting the most out of it at the track, and care about gas mileage, go with 4.10s for one more reason: When you put your gears in your differential cross pin, especially on a 31 spline diff (which I'd suggest) will have to be milled down on one side to be able to slide in past the much thicker ring gear - this happens with 4.30s and up.

96gt02 · 12-04-2013, 05:51 PM

Do yourself a favor and get the 4.10s, you will love them especially in an automatic. My reasoning (from someone who has had both 3.73s and 4.10s in the same car) Going from the 3.27s to 3.73s will def give you a noticeable improvement in acceleration however going from 3.73s to 4.10s will also give you about the same improvement since its about the same decrease in gear ratio, so by going with the 4.10s from the start you are basically doubling your improvement over the 3.73s and either way your spending the money on the install. Your car will only rev like 200 rpm higher on the highway with 4.10s over 3.73s which will barely affect MPG, and your city mileage will actually generally increase to offset the highway lose. As far as install, your best bet is to get the master rebuild kit with all the seals and bearing since it getting torn apart anyway. The kit from latemodel you posted has this kit in it. That kit comes with everything you would need but if you wanted it wouldnt be a bad idea to also have your tlok rebuilt while its all apart anyway especially if the car has a lot of miles and the kits are only like $80 for stock or $110 for the carbon discs. Hope this helps!

11-24-2013, 09:10 PM	#1
Skymack Registered User Join Date: Apr 2013 Location: Charlotte, NC Posts: 25	Which gears for an auto? I have an '04 automatic Mach 1 and the previous owner told me that he put 3.27 gears in it. Do you guys think I should change the gears? I'm thinking about either 3.73 or 4.10's. I mainly drive open roads with little city driving. I don't plan on adding any FI. Also, what else do I need to buy besides the gears themselves for the install? I would have a shop install them for me. I know there's a ton of threads on gears, but most are regarding manual trans. and hardly any compare 3.27's. Thanks!

11-24-2013, 09:22 PM	#2
SuperMach1 Never Satisfied Join Date: Sep 2007 Location: San Antonio, TX Posts: 1,134	Re: Which gears for an auto? What are your plans with the car? Is it a daily driver? I have an auto with 4:10's but thinking if putting some 4:30's in. If your car is a dd I would go with 4:10. __________________ P1 8psi @ 6k PA Transmission DD 3,600 Stall BBK LT's w/ 3in Collector Custom 3in X-Pipe Custom 3in CB w/ Pypes 3in M-80's Built Rear w/ 4:10 415/383 PB 11.80, @ 119 with a 1.71 60ft Tuned by http://www.southtexasperformance.com/ Built WAP Block, 10.5:1 compression, 14psi, E-85 Coming soon.

11-24-2013, 10:05 PM	#3
FOURCAMS Registered User Join Date: Sep 2013 Location: Beaufort NC Posts: 54	Re: Which gears for an auto? I'm in the same boat with my auto, was looking at 3.90's now almost set on 4.10s

11-24-2013, 10:07 PM	#4
Skymack Registered User Join Date: Apr 2013 Location: Charlotte, NC Posts: 25	Re: Which gears for an auto? It's my daily driver. Sorry, I forgot to mention it. I plan on getting gears then probably getting a dyno tune. I really doubt I'll ever take it to the track.

11-25-2013, 12:06 AM	#5
stellasmechanic Registered User Join Date: May 2008 Location: Cocoa FL Posts: 1,207	Re: Which gears for an auto? If you don't care about gas mileage, 4.10 or 4.30 would be my choice. Have had three auto cars (guess four with my latest). I started out at 4.30 and was okay except for the highway at 80 mph was a little high on RPM for me. 4.10 would have been perfect. I'm at 4.56 now but only see about 2k street miles a year. Screams on the highway but sure is fun to drive. Requires good tires though. If you care about gas mileage, 3.73's or 3.90 would be my thought. Gears kill gas mileage pretty quick going from 3.27 to 4.10 especially on the highway. My .02 for what it's worth. __________________ Wife's car: "Stella" 2003 DSG. Auto, 4:30's, 4800 Stall, aluminum DS, 26 inch slicks on 15 inch rims, skinnys, psr / aje hybrid k member and VMP tuned, GT front brakes, 1 3/4 headers and dumps, UWP pulley, Team z control arms. 7.90 - 1.75 60 foot. 12.37 1/4 mile 110.29 MPH (800 DA or so) With Roy PSR 1.71 12.25 at 1600 DA (no tune) 4.56 gears 1.68 12.09 My Car: "Nadia" 2003 TR Auto, Parted out Project beat Stella, engineless 03 DSG. Only goal is to beat my wife.

11-25-2013, 12:07 AM	#6
Mustang9668 saving pennies Join Date: Apr 2008 Location: Griffin, Ga Posts: 1,487	I've been daily driving my mach with 4.10s for a year now with no regrets. I still can get 20+ mpg highway with no problems. Sent from my SCH-I535 using Tapatalk __________________ 03 Mach 1--Auto, 4000 stall, 96 cobra intake cams, 4.10s, ARH L/T's, off road X, Moser 31 spline axles, Eaton Posi diff., MM FLSFC, Tokico D-Specs, k&n filter, 17x9/10.5s AFS Mac wheels 03 Cobra--18x9/10.5 TSW Nurburgring Wheels, Nitto NT05's 275/295, Stiegemeier ported, 2.87” pulley, Canton 9-qt oil pan, Spec Stage II clutch, MM coilovers, Bilstein Shocks/Struts, LFP heat exchanger, LFP radiator, Evans cooling system, 14" Brembo 4 Piston calipers, 470whp, 460ft-lbs

11-25-2013, 12:23 AM	#7
Skymack Registered User Join Date: Apr 2013 Location: Charlotte, NC Posts: 25	I'm not going to go above 4.10's. I'm torn between 3.73 and 4.10's. I'm leaning more towards 3.73 because of the gas mileage. My car pulls pretty hard with the 3.27's (chirps tires going into 2nd). Will going to 3.73 make a big difference in acceleration?

11-25-2013, 09:14 PM	#9
Skymack Registered User Join Date: Apr 2013 Location: Charlotte, NC Posts: 25	Re: Which gears for an auto? Thanks guys! I'm thinking about ordering this: http://www.latemodelrestoration.com/...r-End-Gear-Kit Is that everything I would need if I had a shop install them? I know my speedo will be off and you can use a tuner to recalibrate it, but is there any way to recalibrate it without using a tuner? I have an SCT handheld tuner, but it makes my exhaust quieter and after hearing the horror stories from them screwing up A/F ratios I got nervous about it and took it off.

11-25-2013, 09:59 PM	#10
Mach828 Dark Knight Join Date: Nov 2009 Location: Albuquerque, NM Posts: 5,759	Go with the 4.10s! That kit has everything you'd need. Use the SCT. Get a good dyno tune! Sent with a shot of DROID go fast __________________ Vortech V2 S-trim, E85, A2A Treadstone, Comp cams, built engine, full exhaust, built rear, built 4r70, more mods. Tuned by me with SCT Advantage

11-25-2013, 11:41 PM	#12
Mach828 Dark Knight Join Date: Nov 2009 Location: Albuquerque, NM Posts: 5,759	Im not the one to be asking on going conservative with gears. I've got a supercharged mach with 4.56 gears and a lower overdrive transmission than stock. I just think 3.73s will barely be a difference. You won't see the drop in the city but you will in the freeway. Sent with a shot of DROID go fast __________________ Vortech V2 S-trim, E85, A2A Treadstone, Comp cams, built engine, full exhaust, built rear, built 4r70, more mods. Tuned by me with SCT Advantage

11-25-2013, 11:48 PM	#13
Mach828 Dark Knight Join Date: Nov 2009 Location: Albuquerque, NM Posts: 5,759	Here are the rpms for each at 75. 26" stock tire. Auto overdrive is .698 3.27 - 2,200 3.73 - 2,500 4.10 - 2,700 Sent with a shot of DROID go fast __________________ Vortech V2 S-trim, E85, A2A Treadstone, Comp cams, built engine, full exhaust, built rear, built 4r70, more mods. Tuned by me with SCT Advantage

12-04-2013, 12:58 PM	#14
Fosters LS1-stock Join Date: Dec 2003 Location: Chandler, AZ Posts: 1,550	Re: Which gears for an auto? I have 4.56s in my marauder, though that's on a 29" tire, so it's about as 4.10s would feel in a mach. They are much more fun than the 3.55s it came with stock, but not quite as fun as the 4.56s I had in the mach with the t56. There's very little difference between 4.10 and 4.30; if you don't care about getting the most out of it at the track, and care about gas mileage, go with 4.10s for one more reason: When you put your gears in your differential cross pin, especially on a 31 spline diff (which I'd suggest) will have to be milled down on one side to be able to slide in past the much thicker ring gear - this happens with 4.30s and up. __________________ 2013 gt - TBD 2004 mach1 - 12.31@110.17, 1.645 60' - SOLD

12-04-2013, 05:51 PM	#15
96gt02 Registered User Join Date: Nov 2011 Location: Jersey Posts: 442	Re: Which gears for an auto? Do yourself a favor and get the 4.10s, you will love them especially in an automatic. My reasoning (from someone who has had both 3.73s and 4.10s in the same car) Going from the 3.27s to 3.73s will def give you a noticeable improvement in acceleration however going from 3.73s to 4.10s will also give you about the same improvement since its about the same decrease in gear ratio, so by going with the 4.10s from the start you are basically doubling your improvement over the 3.73s and either way your spending the money on the install. Your car will only rev like 200 rpm higher on the highway with 4.10s over 3.73s which will barely affect MPG, and your city mileage will actually generally increase to offset the highway lose. As far as install, your best bet is to get the master rebuild kit with all the seals and bearing since it getting torn apart anyway. The kit from latemodel you posted has this kit in it. That kit comes with everything you would need but if you wanted it wouldnt be a bad idea to also have your tlok rebuilt while its all apart anyway especially if the car has a lot of miles and the kits are only like $80 for stock or $110 for the carbon discs. Hope this helps!

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