Differential replacement
Thread Starter
Pro
Joined: Jun 2002
Posts: 726
Likes: 45
From: Marquette MI
Differential replacement
My 2002 six speed with 82,000 miles is developing some differential whine at 60 to 65 mph. It seems to be slowly getting louder. I can easily drown it out with the radio but I like my car to be perfect and it's bugging me. My mechanic says the only solution if to replace the ring and pinion gears or the whole rear end. Fluid is not down. My car is a summer time daily driver. So I have questions about rebuilt rear ends -specifically ratios. I now have the stock 3.42. If I buy a rebuilt rear end what ratio should I use? I do not race my car. Gas milage is a concern but not a huge issue. I don't want to go to a 4.11 so what are the pros and cons of 3.73 vs 3.90 in terms of performance and milage compared to stock? Any recommendations for a vendor? I'm looking at West Coast Corvettes. Did a search and could not find much.
Tech Contributor
Joined: Aug 2008
Posts: 2,902
Likes: 21
From: Oak Hill Virginia
Long story short (easy since you don't track your vette):
3.90: Pro - The sensation that you've added about 100hp to your car (note that no real power is gained but it will FEEL a lot quicker) Con - Your gas mileage will be marginally less than with the 3.73
3.73: Pro - The car will feel a little quicker than stock but nowhere near as much as with the 3.90. The car will get marginally better gas mileage than with the 3.90. Con - Your gas mileage will be marginally less than stock.
Also, your cruising RPM's will be slightly higher which may be something you should take into consideration if you have an aftermarket exhaust that has issues with resonance.
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
I would recommend you use RKT56 for your vendor. Rick is a great guy to work with and is in a much better position to address your questions than most on this forum... Give him a call.
Long story short (easy since you don't track your vette):
3.90: Pro - The sensation that you've added about 100hp to your car (note that no real power is gained but it will FEEL a lot quicker) Con - Your gas mileage will be marginally less than with the 3.73
3.73: Pro - The car will feel a little quicker than stock but nowhere near as much as with the 3.90. The car will get marginally better gas mileage than with the 3.90. Con - Your gas mileage will be marginally less than stock.
Also, your cruising RPM's will be slightly higher which may be something you should take into consideration if you have an aftermarket exhaust that has issues with resonance.
Long story short (easy since you don't track your vette):
3.90: Pro - The sensation that you've added about 100hp to your car (note that no real power is gained but it will FEEL a lot quicker) Con - Your gas mileage will be marginally less than with the 3.73
3.73: Pro - The car will feel a little quicker than stock but nowhere near as much as with the 3.90. The car will get marginally better gas mileage than with the 3.90. Con - Your gas mileage will be marginally less than stock.
Also, your cruising RPM's will be slightly higher which may be something you should take into consideration if you have an aftermarket exhaust that has issues with resonance.
DITO!!
Your in good hands with Rick! Have him beef the unit up with C6 ZO6 parts for reliability!
Thread Starter
Pro
Joined: Jun 2002
Posts: 726
Likes: 45
From: Marquette MI
Thanks for the advice guys. Before I do anything I will talk to Rick. May take a drive out to Maryland and have him rebuild. Will also check with Gene Culley re a new GM diff. There's no big rush on this - I'm just trying to educate myself now.
