3.21 Vs. 3.92 gear, worth the money?

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ljhaynes

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I’d like to know everyone’s opinion on if a 3.92 gear is worth the money if you have a 3.21? I have a 3.21 8 speed on 33’s and the truck struggles moving these tires. Wondering if the 3K plunge is worth it? Thanks!
 

NOV87

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What were you driving before, I wonder?
I thought 8sp and 3.21 is a pretty good combo.
 
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ljhaynes

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Gen 4 Ram 1500 6 speed with 3.55. These are 12 inch wide 33’s. Just figured 3.21 8 speed would handle them tad better.
 

Elvira

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I have 275x60x20 cooper dicoverer at3's, 33 inches, 11 inch wide, 3.21 gearing with the 8 speed...I couldn't ask for a better combo for what I use the truck for. It pulls hard and easily cruises as fast i would ever need. Being a short bed regular cab may be a big advantage too over a quad cab or crew cab, so not a real fair comparison....400 hp doesn't hurt either. As to your question, i would not spend that much on re-gearing unless you are doing yourself. It may take a few seconds longer to get to your speed compared to 3.92, but cruising you would not notice the difference anyways.
 

corneileous

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As far as spending the money to upgrade from the 3:21's to the 3:92's, I'd just keep what I had unless I really started towing a lot and heavy or if I wanted to go up to a larger tire.

But with all that said, I already knew I wanted the lower gears in my truck so the truck I bought already has them.
 
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Not worth it if you are just going to have 33s ... if you want 35s going to 3.92s is still not worth it, going to 4.56s is what you should get if you wan to regear for it to be worth it in my opinion ....
 

Hemi drifter

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I have 3.21s, 3.55s and 3.92s. In different trucks.

The 3.92s are by far he best driving of all 3.

The 3.21s are ok, but i get better fuel. Economy with the 3.92s.

Go figure????

I completely agree with @Bigskyroadglide. When I bought my truck (2014 1500 limited 5.7 w 8spd) it came with the lame 3.21 gears and no posi lock, and I hated it. Took forever to get up to speed on the highway, but I could barely get moving in the rain or snow without putting it in 4x4 because of the one wheel Peel.
I spent the 3k to swap out my diffs to 3.92's with a limited slip rear end and I couldn't be happier! Now my truck f@$#ing moves! It is by far the best money I have spent on it so far (followed closely by my hemi fever custom tune and my stealth box). The truck is sooo much fun to drive, it zips through the gears like a race car, I can tow more, AND I get better fuel economy. In my mind the 3.21s are **** gears and shouldn't even be an option, that's how much I love my 3.92's.
Worth. Every. Penny.
 

Hemi drifter

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One final note, you say 3k, and I did spend that much the first time because I was working away from home for a while and didn't have my tools or a garage available. But the second time I did one of these swaps I went to my local junk yard and got both from and rear complete 3.92 axles off a newer truck, with lower mileage, and only paid $600 for the front and $800 for the back, and they're fairly easy to swap out yourself. So 15hundie is what it cost me the second time. Totally worth it imho.
 

Roadwarrior 1500

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I have a '17 crew with 195k miles, 3.21's, 8 speed, Hemi, Modified exhaust, CAI, with Falken Wildpeak tires and have no issues. I don't tow with the truck but do a lot of highway and get 22 mpg (if I do the speed limit). For what I use my truck for the 3.21 is just fine - No struggles.
I also run a pedal commander which will take out your delay/lag issues (like running a Sport+ mode).
 

RamDutyl

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I bought the 3.92 from the factory. Nope, no plans to tow much with Beast, but I'm ready to rock when it's time to move. Retrofit to 3.92? Lots of money for big tire use. Your money, your call. So share some pics.
 

DILLIGAF

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3K ????

You're getting hosed dude. Just go pull axles from a junk yard and swap them yourself.

After that just sell your old axles

You should be more that 1K out of pocket.

My Gen 3 front diff swap and 4.56 gears didnt even cost me 1K once I sold my front Gen 4 front diff.
 

Elkman

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It depends a lot on whether you actually use the pickup as a truck with a heavy load or towing a trailer. Most guys do not so the manufacturers all go with higher gears that improve their fleet MPG for the federal requirements.

I am in the minority and use my trucks as trucks and actually take them off the pavement and so I have always bought ones with 4.10 gears except for my diesel with its 3.73 gears. I also don't pretty them up with bigger tires that negatively affects performance and handling.
 

Irishthreeper

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Before I got my 2500 I had a ‘19 Gen5 1500 with 3.92 gears. It towed very well and it ran like a scalded dog empty. Shocked more than a few “sport sedans”
The 6.4 is powerful but the extra 2k lbs can be felt with the HD.
 

DJ18hemi1500

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Not worth it just for 33” tires, but if you have the ability and space to do axle swaps with 3.92s, you probably don’t need to ask for advice.
 

DJ18hemi1500

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I’d like to know everyone’s opinion on if a 3.92 gear is worth the money if you have a 3.21? I have a 3.21 8 speed on 33’s and the truck struggles moving these tires. Wondering if the 3K plunge is worth it? Thanks!
ljhaynes there are also several threads that address this on the site if you haven’t searched already.
 

1stGen4me

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Anybody buying a truck with 3.21 axel ratio needs to learn the hard way that a taller ratio doesn't save gas at all only makes the hemi engine or tinker toy V6 work harder 3.92 is a good ratio. My neighbor has a 2021 warlock with a V6 engine and 3.21 and we were towing his jet ski this past summer and the transmission was was always shifting in and out of gear. He should have gotten 3.55 at least but the truck is a lease. My other neighbor leased a Jeep gladiator with the tinker toy V6 without a tow package and told me that he can tow 7000 lbs. I told him I would tow his truck and boat on another trailer with my Hemi with 3.92! Some people are not to smart when it comes to buying a properly equipped truck for towing or daily driving.
 

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