3.42 automatic-any benefit
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Teching In
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3.42 automatic-any benefit I have a 01 SS vert auto (3.23) and have the opportunity to buy a complete 3.42 bolt-in rear end for really cheap and was wondering if anyone had a 3.42 auto and their opinions. Also, what benefits, if any, do you guys see performance wise if I do this. Car is basically stock right now, but my mod in the future. Also, car is a base model SS (per SLP), so is the rear anti-slip the same as a Z/28 car or did SS cars get a different posi?
3:42's are perfect for a A4 and it lets u stay in more of your power band so u will rev about 400 rpm's higher but it will not hurt your top end just get u there quicker.The Z-28 & SS have the same rear end unless the SS was orderd w/ the Auburn and it will tell u on your pass. door if not they are both Zexel torson.
I think there would be a benefit, however minute it is, it would be there. You might gain an extra tenth or maybe an extra mph, and might not even feel it at all, but it would help. All depends on how good of deal you have there. It would be worth it to me for a couple hundred bucks to change it out, otherwise just buy another gear set for your existing rear end.
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Teching In
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My 3.23's are fine. Car only has 15,000 miles. Just wondering what you guys thought. Would like to talk to someone who has done the change and see what they thought. I did a swap from 3.92 to 4.56 in a Dakota R/T and hated the end result. Never had a chance to run the strip after the change, but truck "felt" much slower everywhere. May have just been a feeling, but definitely like the feel of the 3.92's better. I know this current swap won't be near the difference because it's not much of jump, but I think 3.42's would provide some speed and help with future mods. Anymore opinions appreciated. Thanks.
Wow. There's no way I'd mess with swapping gears or a full rear end to go from 3.23 to 3.42. Just doesn't seem worth the time/money at all. Go 3.73s. I daily drive them (highway and city) and it's fine.
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Launching!
Joined: Feb 2010
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From: Shawnee, OK
the 3.73's are just a better jump from the 3.42s. itll help some but the driving difference wouldnt be much different from 3.73s so there isnt really much point in getting the 3.42s when you could make a little bigger jump and see much better results
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I can get the complete assembly for about the same price as the ring and pinion and labor to install. Also, I don't really want the whine that comes with gear swaps. I've yet to be around a vehicle that had a gear swap, no matter how "right" tolerances, etc. were that didn't whine. If I go with the whole assembly, gears would be factory installed which is much better in my opinion. I don't want to do it for no benefit, however. Car is a weekend cruiser, and will be taken occasionally on long trips, so driveability and fuel mileage/ rpm (on highway) is a concern.
Then sounds to me like maybe you should just stick with what you got, if your concerned with gear whine. Ive seen 3.42s whine as bad as 4.10's. And even if it doesnt whine right off, it can easily develop a whine. Take the money for this rear end swap and put some exhaust on it.
I owuldn't do it. i would go with a 3.73 before I would waste my time going to a 3.42. And only gears set up bad will whine. Set up properly, most gears won't whine, at least none that I did.
From 3.08 to 3.42 there was a difference even for just a street car. I love my 3.42 rear. And mpg wasn't negatively affected at all - got 32mpg last tank 
But, going from 3.23 to 3.42 makes me wonder if it would really be worth it or not.
But, going from 3.23 to 3.42 makes me wonder if it would really be worth it or not.
Persdonally I'd stick with the 3.23's. Going to 3.42 is such a small jump, and like you said, going to a non factory gear like a 3.73 might leave you with gear whine. And IMO 3.73's is too much if you do much highway driving anyway.
I have a 2.73 rear, which is lowsy for performance, but great for mileage. I'd love to go with a 3.42, but I wonder about how much mileage I'd lose. I'm actually thinking the 3.23 might be a better way to go.
So yeah, stick with what you got.
You migh be better off putting that money toward a converter, it seems like that's one of the best bang for the buck mods you can do on a A4.
It might not hurt to buy the rear anywya if it's really cheap, you could always sell it and make a few bucks, or it certainly doesn't hurt having a spare lying around just in case.
I have a 2.73 rear, which is lowsy for performance, but great for mileage. I'd love to go with a 3.42, but I wonder about how much mileage I'd lose. I'm actually thinking the 3.23 might be a better way to go.
So yeah, stick with what you got.
You migh be better off putting that money toward a converter, it seems like that's one of the best bang for the buck mods you can do on a A4.
It might not hurt to buy the rear anywya if it's really cheap, you could always sell it and make a few bucks, or it certainly doesn't hurt having a spare lying around just in case.
Don't do it. If your car is basically stock A4 switching from 3.23 to 3.42 is a waste of time and money. STOP! You will at best see a .1 improvement in your 1/4 mile times and they would feel no different. If you were bracket racing and every tenth made a difference then maybe, but for a daily driver street car no. I wouldn't change the gears unless I was swapping the rear at the same time and then switch to 3.73 or bigger. The larger gears have smaller teeth than a 3.23 or 2.73 and are easier to break. We all know how weak these 10 bolts are so why add more stress and increase your chance of breaking it. I would put that money towards a stall converter (vigilante or Yank) maybe a 3200 stall. When I installed my 3200 vig my 1/4 times dropped a .5 (half a second) you wont get that with a gear swap. Just food for thought good luck.
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It's not just a ring and pinion. It's an entire rear axle assembly. Complete from rotor to rotor, so should be know gear whine issues since gears were factory setup. This is the main reason I was considering it. I could just unbolt my rear and slide this one in. I agree on the torque converter being a help, but don't have the money or time to do that right now. I could get this entire rear for around $450. I thought that sounded pretty good consider it comes with all brake components, springs, etc.
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Oh yeah. I'm going to put it off. After doing some thinking and listening to you guys opinion, I think I would be better off to save money and put a 12-bolt or 9-inch rear if decide to do a rear end change. Thanks to all.