Traction Lock & Gears

[BlackenedSVT]

So I have my 02 GT and I drive it 75% of the time on the highway, I WAS planning on getting 3.73 Gears, but lately I've been thinking about the 4.10s again. I guess i'll have to look at one of those RPM calculators later to check the rpms at cruising speeds.

What gear would you recommend and why?

I have another question however, What exacly is a traction lock and where can I get one? How do they work, is it like a posi-rear differential?

If I could get a posi-rear and 3.73s, I might take that over the 4.10s.

I kind of want to take my car to the track 3 times at least this summer, however, my car *IS* my daily driver...

 

[trinity_gt]

So I have my 02 GT and I drive it 75% of the time on the highway, I WAS planning on getting 3.73 Gears, but lately I've been thinking about the 4.10s again. I guess i'll have to look at one of those RPM calculators later to check the rpms at cruising speeds.

What gear would you recommend and why?

Go to an on-line gear/RPM calculator. Punch in the numbers and find out what RPM you'll be turning at the speeds you drive at. Go out in your car, select 4th instead of 5th and drive a flat piece of road at that RPM. Judge for yourself whether you're comfortable with your engine at that speed, the exhaust note, noise in the cabin and so on and then make the decision yourself.

One thing with 4.10s is that you may need an aluminum driveshaft depending on what vehicle speeds you plan to cruise at. A shorter rear gear results in higher driveshaft RPM and the factory steel piece may hit a critical speed at which it may start whipping and vibrating...

I have another question however, What exacly is a traction lock and where can I get one? How do they work, is it like a posi-rear differential?

"Posi" derives from the name of the GM limited slip system they called "positraction". It's just the name of a product, much like "NOS" is used often to represent nitrous even though it's a business name..same idea with "Kleenex"...

The Traction Lok is Ford's "posi". It's a clutch-pak based LSD system for the differential. Your 02 GT already has one from the factory. Depending on the miles on the car and how well its performing, you might consider upgrading the thing with a rebuild kit and even an F150 spring to stiffen the bias up some when you have the gears done...

If I could get a posi-rear and 3.73s, I might take that over the 4.10s.

It's all subjective. I personally have 3.73s on order and that'll be fine for me. An increase of 14% in rear wheel torque sounds good and I'm happy where my engine ends up on the tach at the speeds I typically travel. I don't race much at all but that could be another factor you might think of...if you drive to the track and bolt on DRs you might find the 4.10s better to dig out of the hole.

There is no perfect gear because everyone has different needs & wants. I personally find the factory 3.27s a bit tall. 5th is barely usable with the 4.6 below 2000RPM and I want a bit more punch around town without a high RPM highway penalty. Personal preference. Do some research and find out what you like best

 

[02BlkStang]

Well said.

 

[Nick02GT]

Starting to get the ''1 wheel peel'' when i give her around the corners. Probably time to rebuild the clutch pak from the rear diff right?

 

[trinity_gt]

Starting to get the ''1 wheel peel'' when i give her around the corners. Probably time to rebuild the clutch pak from the rear diff right?

The factory bias is comparatively pretty low I think to ensure the diff slips in the wet, a nod to safety and such. If the diff is already slipping as it is in a corner, I don't know if there's enough factory bias in the TLok to get equalized torque back to both wheels again. For that I think you'd need a heavier spring or even a different LSD technology there.

My low-miles (37,000KMs/23125mile) 02 GT does the same thing...in the dry, mid corner it'll more often than not break one tire loose if I nail it. Starting from a straight line though it's two nice fat, parallel patches if I side step the clutch. I think this is normal for the TLok.

 

[BlackenedSVT]

Go to an on-line gear/RPM calculator. Punch in the numbers and find out what RPM you'll be turning at the speeds you drive at.

Can you link me real fast to a good calculator?

The Traction Lok is Ford's "posi". It's a clutch-pak based LSD system for the differential. Your 02 GT already has one from the factory.

Yeah I originally saw the V-6 forums talking about gettinga traction lock, so i guess their cars don't have that stock, like the GTs do. However, doesn't ford use a "limited slip" differential, because "posi" isn't that. So i would assume that if traction lock = posi, then traction lock was not a limited slip differential. Thats why I was wondering. I know my GT has limited slip, and i was only going to upgrade it if the t-lock was exaclty like a posi, so i guess i'll just keep the limited slip.

It's all subjective. I personally have 3.73s on order and that'll be fine for me. An increase of 14% in rear wheel torque sounds good and I'm happy where my engine ends up on the tach at the speeds I typically travel. I don't race much at all but that could be another factor you might think of...if you drive to the track and bolt on DRs you might find the 4.10s better to dig out of the hole.

Yeah most of my driving is on the highway. And im thinking 4.10s will be a bit much. I DO however want to go to the track and have a nice off-the-line car. However, my car IS my daily driver, and don't want the 4.10s to be too much. I will be staying N/A however, so that makes me think to go with the 4.10s again.

There is no perfect gear because everyone has different needs & wants. I personally find the factory 3.27s a bit tall. 5th is barely usable with the 4.6 below 2000RPM and I want a bit more punch around town without a high RPM highway penalty. Personal preference. Do some research and find out what you like best

I agree, 5th gear is useless. I want to shift into fifth and have it as useful as my 4th gear. And I am also figuring that 3.73 will do this, and anything is better than stock as well. So i'm still heavily considering 3.73s.


Anyone have 3.73 in their Daily Driver that is also N/A???

 

[trinity_gt]

Can you link me real fast to a good calculator?

I don't have a link handy at the moment. A search should show one or you could generate an Excel spreadsheet and generate some graphs...

Yeah I originally saw the V-6 forums talking about gettinga traction lock, so i guess their cars don't have that stock, like the GTs do. However, doesn't ford use a "limited slip" differential, because "posi" isn't that.

The TractionLok is a limited slip differential. The FRPP catalog describes the M-4204-F288 as a "Traction Lok limit slip differential are made by Ford and have plate type clutches".

GM's positraction was/is also a limited slip unit:

"Positractions & Limited Slips:
Posis and limited slips transmit equal torque to both wheels when driving straight. However, when one wheel spins due to loss of traction, a patch of ice, mud, too much throttle, etc., the unit automatically provides more torque to the wheel that has traction. Recommended for daily driving, works well in ice, rain, mud and snow. However, in situations where absolute lockup is needed, a limited slip is not the best choice due to the fact that limited slips do slip in some situations.

Positraction is a type of limited slip. The name "positraction" was used by General Motors for their limited slip differential and the name has been associated with limited slips for many years. "

http://www.ringpinion.com/content/technicalhelp/default.asp?pid=128

"What’s the difference between a Limited Slip and a Posi?
There is no difference between a limited slip and a Posi. It’s just a different terminology used by each manufacturer. Posi originally came from the GM-trademarked Posi-Traction. "

http://www.chrismans.com/AskSpankyDiff.html

So i would assume that if traction lock = posi, then traction lock was not a limited slip differential. Thats why I was wondering. I know my GT has limited slip, and i was only going to upgrade it if the t-lock was exaclty like a posi, so i guess i'll just keep the limited slip.

NOS=nitrous...Kleenex=tissue..."posi"=TractionLok=...=limited slip.

Yeah most of my driving is on the highway. And im thinking 4.10s will be a bit much. I DO however want to go to the track and have a nice off-the-line car. However, my car IS my daily driver, and don't want the 4.10s to be too much. I will be staying N/A however, so that makes me think to go with the 4.10s again.

Heh...it's not an easy choice. I dithered for months (over the winter as the car sat in storage) before coming up with 3.73s for myself.

 

[BlackenedSVT]

Heh...it's not an easy choice. I dithered for months (over the winter as the car sat in storage) before coming up with 3.73s for myself.

Yeah I did the same thing when i had my old stang. I had a 98GT (auto) and bought 3.73s for it, and they sat in my room for 4 months and RIGHT before i installed them i traded them in for 4.10s. I personally would NEVER do 4.10s in an auto ever again. Lost so much top end, and Overdrive isn't quite like having 5th gear. But i'm not about to get into that...

Im not worried about top end loss with the 5spd and 4.10s, i just dont want them to be too much since i highway drive a lot and dont want to suck down gas and have my tach at 4k screaming down the highway, since i mostly drive at 90mph.

 

[Thundermouse]

If you have the T-3650 with the .62:1 5th gear and go 4.10s:
70mph = 2327rpms
75 = 2494
80 = 2660
85 = 2826
90 = 2992

If you have the T-3650 with the .62:1 5th gear and go 3.73s:
70mph = 2117rpms
75 = 2269
80 = 2420
85 = 2571
90 = 2722

If you have the T-45 or the T-3650 with the .68:1 5th gear and go 4.10s (the .68 will result in slightly higher rpms than the T-45, .67 vs .68):
70mph = 2515rpms
75 = 2695
80 = 2874
85 = 3054
90 = 3234

If you have the T-45 or the T-3650 with the .68:1 5th gear and go 3.73s:
70mph = 2288rpms
75 = 2451
80 = 2615
85 = 2778
90 = 2942

 

[turboscrew]

Anyone have 3.73 in their Daily Driver that is also N/A???

I just installed my 3.73s a couple of days ago and I love them. Not too much gear seems like its just enough. Mine is a daily driver too but I do about 30 min. on the interstate so I changed my mind about 4.10s. There is only about 200 rpm difference between the 2 so 4.10s wouldn't be bad for someone that doesn't do alot of highway driving. i haven't really dogged it yet but it has alot of pull getting on entrance ramps and especially in 2nd and 3rd at 3000rpms. I' ve heard that 1st is barely useable with 4.10s but its not that bad with 3.73s. If you don't do alot of hotrodding go with 3.73s but if you like to drive hard I would say 4.10s.

 

[Sgt. RedLine]

I have FMS 4.10's, eaton posi and moser 31spline axels behind a 4r70w with the jmod and a cooler. I have no issues running her on the highway where I do often. If you want the 4.10's, get them, just if you are getting a blower, I wouldn't go that size.

John

 

[BlackenedSVT]

If you have the T-3650 with the .62:1 5th gear and go 4.10s:
70mph = 2327rpms
75 = 2494
80 = 2660
85 = 2826
90 = 2992

If you have the T-3650 with the .62:1 5th gear and go 3.73s:
70mph = 2117rpms
75 = 2269
80 = 2420
85 = 2571
90 = 2722

If you have the T-45 or the T-3650 with the .68:1 5th gear and go 4.10s (the .68 will result in slightly higher rpms than the T-45, .67 vs .68):
70mph = 2515rpms
75 = 2695
80 = 2874
85 = 3054
90 = 3234

If you have the T-45 or the T-3650 with the .68:1 5th gear and go 3.73s:
70mph = 2288rpms
75 = 2451
80 = 2615
85 = 2778
90 = 2942

How do I know what 5th gear ratio I have in my T3650. I have an 02 GT so of course i have the T3650...but not sure what gear ratio. If i have the .62 5th gear ratio, i'd DEF go with 4.10s, but that .68 5th gear ration is a bit too high for my highway driving RPMs. I drive at 90mph consistently on the highway. Sometimes faster, sometimes slower of course.

 

[joshheat25]

Sgt. Redline I am debating getting the 4.10's in my Auto GT. You have the 4.10's and also a Moser 31 spline, j mod and a cooler?? What is the J mod and also does the 31 spline axle do anything? also about the cooler is it effective?

 

[97gtconv.]

to do the j-mod go to www.tccoa.com. after that go to technical articles and it will show a list. Read everything they got. I consider some of it the best out there.

 

[joshheat25]

There is like 3 Jerry Mods which one the first one!??

 

[Thundermouse]

How do I know what 5th gear ratio I have in my T3650. I have an 02 GT so of course i have the T3650...but not sure what gear ratio. If i have the .62 5th gear ratio, i'd DEF go with 4.10s, but that .68 5th gear ration is a bit too high for my highway driving RPMs. I drive at 90mph consistently on the highway. Sometimes faster, sometimes slower of course.

At one of the model years they changed the 5th gear ratio in the T-3650, but the only problem is I can't remember which year. I want to say that you have the .68 .... anyways, if it is that close of a call for you between .62 and .68, have you considered getting 3.90s as a happy medium?

 

[joshheat25]

Some good information on that site!! But i still don't know whether to get the 4.10's or not!

 

[Mike97gt]

Starting to get the ''1 wheel peel'' when i give her around the corners. Probably time to rebuild the clutch pak from the rear diff right?

i would go with the stiffer spring for the traction-lok and when you fill the rear back up use very very little additive at first.. drive it.. if it chatters a lot around corners add a little more.. the friction modifier additive is used so the clutches in the trac-lok will slip around corners.. for good stright line performance use as little of this as possible..

 

[Mel96GT]

If you do ALOT of highway driving like me, go with 3.73's. I don't care to hear my engine droning loudly at 80 mph. I don't need to lose anymore of my hearing. Anyways, 5th gear should be a highway cruising gear not a performance gear like 4th, IMO. However, I went with 3.55's since I got a deal on parts and install and all it took was a white, FRPP 23-tooth speedo gear to correct the speedometer. I also plan to go FI in the near future so I definitely didn't want 4.10's. I realize 4.10's are great if you do mostly city/strip N/A driving, otherwise go for driveability and gas mileage. Let the flames begin!

 

[Mike97gt]

If you do ALOT of highway driving like me, go with 3.73's. I don't care to hear my engine droning loudly at 80 mph. I don't need to lose anymore of my hearing. Anyways, 5th gear should be a highway cruising gear not a performance gear like 4th, IMO. However, I went with 3.55's since I got a deal on parts and install and all it took was a white, FRPP 23-tooth speedo gear to correct the speedometer. I also plan to go FI in the near future so I definitely didn't want 4.10's. I realize 4.10's are great if you do mostly city/strip driving, otherwise go for driveability and gas mileage. Let the flames begin!

why flame you... buy what you want... go with 1.73's if that makes you happy, just dont complain when geo's smoke you..

3.55's are a ok gear.. just not that much of a difference fromt he stock gear.. but probally helped some..