mattdracing

I am wanting to do 4.10 gears in my grand sport vette but not sure what all parts im gonna need. i know its pricey but in all my cars i do gears to wake it up...the vette needs it especially with the ridiculously long gears. is RPM the only company i should go through? my car is just a street car. thanks

lockman

really just get the dif from RPM. and replace the one in your car and ship yours back to them. but contact them they will tell you everything you need to know and yes there are other companys that do it too.

TLS_Addict

I am interested in this as well.

Are they a sponsor on here?

Turbo6TA

Look at the info below ...

If you have a GS with the A6 transmission, your 'final drive ratio' in 1st is 11.00 to 1.

The GS with the manual transmission has a 'final drive ratio' of 10.16 to 1 in 1st gear.

This is really very low. Are you sure you really need a set of 4.10 gears in the rear axle?

Turbo6TA

Look at the old Muncie M22 "Rockcrusher" 4-speed transmission. It had a 1st gear ratio of 2.20

Lets say you use this tranny along with a set of 4.56 gears in the rear axle (that was a great drag racing combo back in the day) ... well, that combo will get you a final drive ratio of 10.03 while in 1st.

That's about the same as your GS with the M6 trans and stock 3.42 rear gears ... And it's not even as low as the GS with the A6 trans and the stock 2.73 rear axle gear ratio.


So, again ... do you really feel you need a set of 4.10 gears in your GS?


BTW ... If you want to look at a good calculator for finding final drive ratios, look at this: http://www.gitdirt.com/finaldriveratiocalculator.htm

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lockman

well as for 4.10 gears in the m6 if you have never done it you don't know what your missing it make all gears much better and 6th is very useful.

Turbo6TA

Yup .. 6th will be very useful and 1st won't be useful at all.

mattdracing

i knew i was going to get those "are you sure" responses. im positive. my last mustang i had i put 4.10 gears in and it had 600 hp. yea first gear was kinda useless but it was way more fun to drive. and my car now...i cant even think of getting it to spin the tires in 1st gear if i tried with those 325's on the back. then i shift to 2nd gear and im in 2nd forever. then 3rd forever...etc. 3.90 gears pick up your 1/4 mile time a ton also but im just going all the way to 4.10's for the fun factor. i like to go through the gears quicker and have some fun. not the super luggy loooonnnnng gears i have now it makes the car feel slow when realistically its not

mattdracing

my car is an m6 by the way...sorry i left that out in the OP

speedraider

just go buy a set of headers

mattdracing

i already have headers, intake, tune haha. i just called RPM transmissions and found out for my car since i have the zo6 diff its 2995 to change the gear. no thanks...i think i will do heads/cam instead with that money

Boomer111

I installed 4:10's 2 years ago and still love them. Yes I see a drop in fuel mileage but it is not drastic and I still can get 28 mpg on the hiway if I want to.

Around town and in the mountains it is much more fun.

I went with Forum vendor DTE and bought a complete rebuild differential with upgraded parts. Check out their site. RPM offers this service too.

I looked locally for a installer of new ring and pinon gear and did not have much success.
I was told that the Vette diff is different than others and requires special tools and expertise.

I did not want to gamble so I went with a complete build from professionals.

mattdracing

good deal...thanks for the info! if you dont mind me asking...roughly how much did you spend? i know it will be more expensive for me with the zo6 rear end but just curious

Boomer111

The stage 2 diff was $1895 with exchange and install was another $400.

At the time the Z06 half axles were used now they install the hardened steel ones. I also have the revised oiling system and upgraded clutch packs. The ring and pinion are grynogenically hardened. The case is mangafluxed for cracks and all components are polished for better wear, the reused parts are checked for cracks also etc.

DTE strongly recommends the use of Redline 75/140 gear oil and changes every year. it has worked out fine and this oil includes the anti slip ingredient.

6th gear is now usable on the highway and no need to drop down to 4th for quick passing. 5th will do. Dropping down to 4th will explode the car forward at 70 mph.

I do not track or strip the car or even street race. Just always did not like the tall gears of the C6 MN6, great for fuel economy but just to legging for driving fun. Still do around 165 mph if you care. It is about a 350 rpm rise.

GARY2004Z06

Obviously not a drag racer.

GARY2004Z06

Rodney runs a great shop. If you are going to abuse your car, his rear holds up well. Nothing is bulletproof; however, his rears are superior and they provide great customer service. We have cut numerous 1.3 60's with M6 gearing and 4.10s launching well above what the average person is willing to subject their car to. They offer special upgrades if you intend on doing the same. Ask for TJ and tell him that you want the setup that we run.

chaver450

I just put 3.42s in my 08 A6. Got the differential from RPM. Love it!

C6RaceCar

Whats the deal with changing the diff?? Why not just do gears????

Boomer111

Dunno for sure the technical aspects but I was told that the Vetts diff is different from other cars and special skills/tools are required that are not normal in shops doing this kind of work.

Maybe a real mechanic can enlighten us because I never did get the full picture.

Was told it was safer to get the whole unit rebuilt special.

Turbo6TA

Ok Gary ... Tell me what you disagree on when I said:


"If you have a GS with the A6 transmission, your 'final drive ratio' in 1st is 11.00 to 1.

The GS with the manual transmission has a 'final drive ratio' of 10.16 to 1 in 1st gear.

This is really very low. Are you sure you really need a set of 4.10 gears in the rear axle?
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And BTW ... I am 64 years old ... I was drag racing as early as the late 60s

How about you?

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