DarkSpeed

Hello gentlemen,

I've been pondering doing a gear swap from my stock M6 3.42 to 3.90 or 4.10 ring and pinion...just to prepare her for a cam install sometime in the future and also to make my 6th gear more useful (I have to go 80mph+ to effectively use 6th )

I've done alot of search on this forum, but I honestly need to know how hard is it to do a ring and pinion swap DIY as opposed to paying a shop to do it for you? Anyone ever done it themselves and willing to share?

my car: 99 C5 coupe M6, XS-power catted LT's with B&B Bullets

Thanks in advance!

Rick@RKT Performance

The gear swap on the Vette diff is not as easy as doing it on a solid axle type of diff. First you need special tools to set the initial pinion shims, then you need another set of special tools to assemble the pinion spanner nut. After you set the initial pinion shim, you have to assemble the diff to check the backlash and contact pattern. If they are not within specs, you have to diassemble everything and reshims the sides (you must first press out the side carrier bearing races) and the pinion shims to get the correct backlash and the pattern. On average the diff set up takes me about 4-5 hours (with all the correct tools and stands) but some have taken over 8 hours. I would have a professional set up the diff for you, in the long run you'll be better off.

Dope

I wouldn't do it if you don't have a lot of good experience doing this kind of work. Let a professional set it up.

Having said that, why don't you use 6th until 80+? I use mine anything over 50. The car has tons of power to use it at almost any RPM over idle.

Dope

m6 c5

I use 6th gear all the time as well, anything over 1100 rpm and you should be good on fairly level ground. I tend to wait till 13 or 1400 after I installed my headers, just sounds a little better.

Corvette-Chris

I've been here a long time and I can't recall a single person that did it themselves for reasons that Rick (RKT56) outlined. I'm not saying it's impossible, but there is a reason people employ professionals to do it. The best advice I can give is to contact Rick at RKT56 to fix you up. You absolutely can't go wrong doing so.

Rick@RKT Performance

Thanks Chris!

DarkSpeed, PM me your needs and I can take care of it for you.

dougbfresh

LloydP

I had a neighbor put a 4.10 in his '06. Made it feel faster but I thought it made 1st pretty useless.

He looked into doing it himself but went to unitrax in Anaheim (2008) . A little ways away for you but might be of interest. It is a 2 day job.

DarkSpeed

Thanks for the advice guys!

Rick thank you for offering your expertice, unfortunately I don't have the budget for it now (which is why I wanted to do a DIY ) but will consider it in the future for sure.

btw...anything below 1600 on my 6th and I really feel the car is struggling, not to mension getting horrible has mileage because im forcing the accellerator at such a high gear and low RPM (at 60-75 I actually get better torque AND fuel economy on 5th according to instant MPG) might not be accurate but at least the car FEELS better on 5th at those speeds

m6 c5

I will say the car feels and sounds better in the higher rpms but Im getting over 40 mpg constant in 6th at 50-55 and about 30 in 5th and it drops down significantly as the rpms increase cor me at least.

Bob K

I had 4:10 in my '00 and I loved them. I left them in when I got a 402. They made the car driveable in 5th and 6th, otherwise the exhaust drone was too much.

Rick helped me out with my trans. He's a good person to deal with.

Bob K.