3.42 Ribs
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Joined: Aug 2006
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From: Modesto Ca
3.42 Ribs
C5......... what's the difference between the 1 rib and the 3 rib? When buying used what should I be looking for? Just looking to wake up my stock ride a little and not lose to much gas mileage.
Le Mans Master
Joined: Aug 2005
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From: CA.
St. Jude Donor '13-'14-'15
A 3.42 was available on any C5 manual trans--However a 3.42 out of a Z06 is built somewhat stronger--More ribs (not sure guess you checked) But more importantly the gears are "shot peened" If you look at the diff tag or stamp on a 3.42 out of a Z06---It should say " 3.42SP---that's the one you want for strength !!
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Joined: Aug 2006
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From: Modesto Ca
Any year better than the rest? I would think the less miles the better. What about a new stall, perhaps it won't matter after all it's still the stock motor. Just trying to wake it up a little. Anything besides 2.73 gears in town should help.
Le Mans Master
Joined: Aug 2005
Posts: 5,375
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From: CA.
St. Jude Donor '13-'14-'15
I did both to my car--gears and stall----However if I had to only choose 1 that showed the greatest performance gains---I would pick the stall !!!---True 2.73 are awful high I would only change them if you got a deal on a low miles Z06 diff-----A stall is the single best mod you can make on any automatic car !! Engine or trans !!(IMHO) And I wouldn't mess around with a reworked stock diameter unit as they are junk---And get at least a 3000 stall that is aftermarket and made to handle abuse--
Drifting
Joined: Mar 2011
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From: Richardson TX
Automatic cars had an option for the 3.15 ratio rear end, so that's a good replacement for a 2.73 that still retains really good drivability. All manual C5's, Z06 and non-Z06, have 3.42s, so they're easy to come by. You'll lose some mileage and have higher RPMs while cruising with 3.42s, but a small price to pay for the better performance IMO.
It is my understanding that Z06 differentials have identical cases to non-Z06 C5s that came with a 3-rib diff, but that the gears are shot peened, and stronger.
In GOOD CONDITION, a 3.15 typically sells for ~$300, a 3.42 for ~$500, and Z06 (3.42SP) for ~$700. Your results may vary. Most shops charge $400-500 to replace a differential.
Drifting
Joined: Mar 2011
Posts: 1,412
Likes: 15
From: Richardson TX
On the left side is a "single rib" differential, and on the right is a "3 rib" differential. The only difference is the case rib on the top that splits in 3 for the 3 rib diff.
Typically in C5's when the differential fails, the case cracks, the internal gears and guts rarely break before the case does, so a reinforced case helps keep the diff together for longer.
Typically in C5's when the differential fails, the case cracks, the internal gears and guts rarely break before the case does, so a reinforced case helps keep the diff together for longer.
