footbright

Hello,

New to the C5, I have 2003 Black on black, automatic tranny. I have had it about 3 months and love it!!!!

I would like to install a yank SS3200 and do the rear differential in a getrag 3.42. What is the best way to do it. Buy a z06 rear diff and install or trade in the 2.73 and send a 3.42.

My mods are listed below.

My modes are LG long tube headers, off road x pipe, and exhaust, airaid intake and a tune. The differential and the torque converter are all I am going to do next. It is a somewhat of a daily driver, I use it to ....... lets go do some spirited driving car. SO.... I will not be adding anything else to the car after this.

I have been reading for days on all of the post and it can get really confusing and bog you down. I think after reading all the post that I may have a three rib differential already...hell I dont know...LOL Is it cheaper and smarter just to get someone to install the ring and pinion 3.42 gears??? That is if I have the right differential to do so. So confused...

Also I have found a 1997 Corvette C5 Rear Differential 3.42 Ratio Two Rib Case for around 400.00 dollars. Will this work? If so that would be great!!!!!

If the differential I found will not work please get me pointed in the correct direction, also if you trade the differentials with a vendor what kind of cost am I looking at?

Kind of choppy explanation, but I think you can see what I am wanting and I did not want to make this too long.

Thank you for your time and help in advance!!!!!!

Ben

alxltd1

So first determine what diff you really have:
Look at the build code sticker in the glove box. If you see a G92 then you have the 3:15 optional rear, if not you have the standard 2:73 for an automatic.

If you think the original owner had already swapped out the diff get under the car and look at the diff and find the id tag and it will tell you what ratio it is.



If you are not sure what rib diff you have view the attached: the 3 rib is on the right



Now that you know what diff you have you decide what you want to upgrade if at all. IMO unless you have the skills and proper tools, find an already built diff and swap it in or have a qualified shop do so.

dadaroo

If I needed any serious tranny or diff work I would be shipping them to RPM Transmissions.

v98roadie

I just got through doing the rear diff on my 02 A4. You can look up the thread if you want to see what my experience was. I wound up with 3.73 gears in a 3 rib diff. I still have my 2 rib 2.73 diff in the garage. You need someone that is familiar with Corvette rears. That being said, the change to 3.73 gears is the single best mod I've done to the car bar none. Runs and sounds great. Good luck.

footbright

Excellent information guys, I will see what I have under there and go from there. I do not really have anyone qualified to work on the rear end where I live. So I would either buy one or call RPM to do the work.

Would this work for a direct swap? 1997 Corvette C5 Rear Differential 3.42 Ratio Two Rib Case

Also is there any difference between a M6 and a A4 on the differentials??

Also V98roadie how did the 3.73 affect your fuel mileage and hwy travel. I do like to travel across Florida to places with my wife and do not want it to eat me up in fuel to much.....

v98roadie

Mine runs great on the turnpike at 80+ MPH. It definitely reduced fuel mileage but I don't measure mine real close. I think my foot has a lot more to do with the loss in fuel economy than the diff. It is a beast and I love the feel when I get on it! These engines weren't designed to cruise at -2000 RPMs. GM only did it to meet CAFE standards.

CamminC5

RPM is a great group of guys. Definitely recommend them for any driveline work.

There are some guys on here from Ocala. Look them up and see how they do things.

footbright

V98 roadie thank you for your replies. I think considering the cost effectiveness....I have found a 2003 z06 3.42 diff for sale for 400.00 and it would be less labor intensive for me to just swap them out and considering I am going with the yank ss3200 converter it will suite me just fine for some spirited driving...I hope. If I am correct they did not make a diff with the 3.73 and I would have to have the ring and pinion installed which I think would be a lot more money....diff out of car, change gears, diff back in car......

CamminC5, I am originally from Ocala, where I live now is in Crystal River about 30 miles southwest from there. I will give some old buddies from there a call and see what they know about some shops over there.

So, if I get this 2004 z06 diff, it should be a swap out and then get the pcm reprogrammed for the diff change out?? RIGHT??

The differential is not partial to the Manual or Auto transmission as far as I have read??????

I think this is the route I would like to go. If you guys think different PLEASE voice your opinions and experiences.

THANK AGAIN!! I have learned so much from this Forum!!! Priceless!! Hopefully some day I can offer advise like you!!


OH YEAH, I LOVE THE FACT THIS SITE IS INVOLVED IN DONATING TO ST. JUDES CHILDRENS HOSPITAL. I AM A CANCER SURVIVOR FROM 1985!!! THEY SAVED MY LIFE!! ALTHOUGH THEY GAVE ME ABOUT 2 YEARS TO LIVE...I AM NOW 38 YEARS YOUNG WITH NO ISSUES EVER!!! I THANK GOD AND ST JUDES EVERYDAY!!! ITS THE ONLY CHARITY I GIVE TOO!!! DANNY THOMAS THE FOUNDER WAS A UNBELIEVABLE MAN GOT TO MEET HIM BEFORE HE PASSED!!!

footbright

Awesome information, and great pictures!!! Thank you for the reply!! I worl offshore and as soon as I get home I will get under her!!

alxltd1

My pleasure. I live right outside of Tampa. I can recommend a shop in St. Petersburg Florida, Power Tech Performance, who can assist with any work you may need.

footbright

Am I correct about the differentials, if I want to go higher than 3.42 I would need them to be installed and such....if that is the case I would just go with the direct replacement of the 3.42 2003 z06 diff.

Also no difference between auto and manual tranny??

Also, you know of a good tuner that way, not really sure of the one here..

Thank you,

Ben

BigGun

You are correct. Be sure to see what ratio you have now. If you already have 3:15 the change could be a little disappointing. The change is not that dramatic. You might want to check with RPM or Kim at RTK as they may have some already built diffs with 3:73 in the shop. They will be a lot more than 400.00 dollars but you will really notice the change.

alxltd1

As stated you are correct. Installing ratios above 3:42 require getting a built diff from someone like RTK or having ring and pinion installed in your diff case. However, installation is not a routine job and to have it done correctly you need a shop who knows what they're doing or you wind up with a whining and quick wearing diff. And as stated the cost is not insignificant.

Regarding a tuner, check with Joe at PowerTech Performance, he is the owner and can set you up.

Patches

Here's a thread detailing my Yank 3200 stall and 3.42 diff install:

https://www.corvetteforum.com/forums...mega-pics.html

An extra step not required for the manual tranny C5's is swapping the A4 seal plate. Here's the seal plate I transferred from my 2.73 diff to my 3.42 diff during that install. It's held in essentially by the O-ring so it's not pressed in with a lot of force. You should replace the large, outer O-ring and shaft seal while it's out.

footbright

Patches,

Awesome work and pictures in the thread you posted. Thank you for taking the time to reply and share the experience with us. I will do as you suggested with the seal plate. I will be keeping the 3.42 gears unlike your 4.10 ones you installed, I am going to be doing a little more highway use. Thanks again!! Hope Mrs. Patches in enjoying it. I was worried about driveability and you and others have put that to rest for me!!

Good motoring!!