Another Re-gear Thread

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raggedolram

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Hello all, I have a 2020 1500 4x4 with 3.21 gears. We've outgrown our travel trailer and want to upgrade. I was originally planning on having the truck regeared to 3.92's, but I am looking for some clarification. I called the dealer because I'd like to have them do it (warranty peace of mind). I was quoted $3700 because they said they had to replace the whole front axle to make the swap. Can anyone confirm that the 3.92's won't make the direct swap? Seeing as you can order these gears as a cheap upgrade, it didn't make sense to me that it would require an axle swap. Please tell me this shop foreman has no idea what he's talking about, so I can take it to a different dealer. I've done gear swaps myself before on jeeps, so I have a clue, but I wanted to confirm with the group. Thanks in advance.
 

caulk04

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They likely don't have someone who wants to set up the gears. The carrier is welded to the ring gear in these newer axles, so there are more parts to replace but no way the entire axle needs done...unless I don't understand what I've read about these.

If it were me, I'd be checking with wrecking yards to see if you could buy complete 3.92 axles from one and sell them back yours.
 

Gr8bawana

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Honestly if you have a 4WD it's often more cost efficient to trade for another truck with 3.92.
Really? Why would it make sense to spend 50-60 thousand $$ on a new truck rather that a few thousand for a re-gear? :crazy::mexsmoke:
 

mtofell

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fwiw, I considered a re-gear and wanted to keep my warranty intact and was still just going to have a private shop do it. Sure, I'd have no warranty on the gears from FCA (but did from the shop). Anything else I doubt the dealer would ever know and even if they did the numerically higher gears are easier on the tranny and drivetrain so they'd have a hard time claiming my mod hurt the truck.
 

tidefan1967

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Hello all, I have a 2020 1500 4x4 with 3.21 gears. We've outgrown our travel trailer and want to upgrade. I was originally planning on having the truck regeared to 3.92's, but I am looking for some clarification. I called the dealer because I'd like to have them do it (warranty peace of mind). I was quoted $3700 because they said they had to replace the whole front axle to make the swap. Can anyone confirm that the 3.92's won't make the direct swap? Seeing as you can order these gears as a cheap upgrade, it didn't make sense to me that it would require an axle swap. Please tell me this shop foreman has no idea what he's talking about, so I can take it to a different dealer. I've done gear swaps myself before on jeeps, so I have a clue, but I wanted to confirm with the group. Thanks in advance.
A lot of it depends on how big of an upgrade your talking about. If your approaching 10K total weight you might want to look at a 2500.
 

68PowerWagon

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1st. I don't think I would want a dealer to do it. Find performance shops that do this kind of thing all the time. If it is done by a reputable shop, it most likely would not affect your warranty. Most of your FCA Employees have probably never done a diff swap in their entire career. I understand you are worried about your warranty but I would like to know if anyone in their shop has ever done a swap before. 2nd. He might actually be right. As said above I think the ring gear is welded in, so basically at that point you pretty much are replacing the whole thing. On my 2500 I had to have the front carrier swapped out along with all of the other components. Which put me at about $3,200 if I remember correctly.
It is money well spent, but you have to do some real calculating first. How old is your truck, how is the condition of the rest of your truck, how close to max will you be after the purchase of a new trailer. Since your truck is so new, & if you plan on keeping it awhile longer, this might be the best route to go. With the 8 speed tranny that you have, I would also consider going to the 4.10's. It will affect your mileage maybe .5mpg, so if you drive a lot of miles as a daily driver maybe not. It doesn't kill your mpg like some would like for you to believe. I went from 3.73's to 4.56's & only lost .5mpg With my horribly geared 6 speed tranny I probably should have considered going on up to the 4.88's. All the posts you will read about gear swaps the guy says I probably should have went for even shorter gears. Never fails! :Big Laugh: Hope this gives you more to think about.
 

ramffml

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Upgrading to the 3.92 will not really help you. Do the math, both the 3.21 and the 3.92 share 5 almost identical gear ratios (the ones you use while driving in the city and on the freeway while towing). The first two are shorter on 3.92 to get you moving, and the 3.21 has a taller final gear.

So once both trucks are rolling and in 3+, the 3.92 has no advantage left. The 3.92 "may" have been worth it if you got it with the truck, but regearing is a waste.

And finally, what is your payload? Because that will still limit you in terms of what you can pull, us 3.21 guys can still tow more than we can carry so unless you're driving around with an empty truck and only person driving, chances are payload will limit you before the 3.21 does.

Just my pair of pennies.
 

RLJ10X

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More weight should be given to the man who has geared down, than to the nay sayer who hasn't.
 

Daw14

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Not the same , but 2wd 355. To 456. Loving it more then before. Would I do it again ? Absolutely! Regrets ?NO.
 

Bldrinker

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Get a different truck. 3.21 to 3.92 is not going to be a big difference.

Camping buddy of mine had 3.21 8 speed truck and pulled his 6,000lb trailer easy.

you run out of control of the trailer at around 7,500-8,000lb with a 1500.

power is not a problem at those levels.
 

kurek

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Some food for thought, my Ram is a 2015 with the RFE transmission and 3.55 gears - in this configuration it has the highest GCW rating and highest (4wd) trailer weight rating, higher than with 3.92's and higher than the 8-speed with 3.92 gears. I don't know what specific factors led Ram to rate them this way but here's the chart:

towing.png

So armed with that information, here are the final drive ratios for the 8HP transmission with 3.21 gears vs. the final drive ratios for the 65RFE transmission with 3.55 gears:

GEARZ.png

In other words if a Ram with the weaker 65RFE transmission and a 10.65:1 first gear ratio can have the highest factory GCW rating then a Ram with a stronger trans and a 50% deeper first gear ratio should have no difficulty at all. If regearing was free, or if you have enough income that the price is no big deal to you then sure go for the gears.. but otherwise I wouldn't worry about it.

As for the price, yeah I'd believe that the front axle assembly would be their first choice for changing it out (vs just doing the carrier) - if it was my personal truck and I was set on regearing I'd get two complete axle assemblies from a wrecking yard and swap them in whole. I don't have the tools or talent for gear setup so I'd have to pay a pro for that part of the job otherwise.

GEARZ.png

Edit: I'm not sure why it keeps showing that table twice I delete the 2nd one and it reappears on its own. So I guess you get the same info twice.
 
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ramffml

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More weight should be given to the man who has geared down, than to the nay sayer who hasn't.

The math doesn't lie, but "confirmation bias" is a real problem; we change something, we want to notice a difference, so we notice a difference. That's why we should always try to understand the theory/math first to see if we're just fooling ourselves or noticing something actual and real.

I used to go to a lot of audiophile websites but couldn't stomach it after a while. Bunch of guys all convinced they can hear miniscule differences in sound between one DAC and another DAC but yet when you ask them to do a double blind study (switch the devices around without them knowing which one is playing and ask them to name it) they refuse to do the test and come up with all kinds of stupid reasons why the test won't work. We are REALLY good at fooling ourselves (I include myself in that of course).

So no; just because someone has done something, doesn't mean they are more of an authority on how well it does or does not work. If you were right, we should all go out immediately and buy some new cold air intakes and get ourselves a nice performance boost.
 

RLJ10X

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I never said a word about gold air.

Numbers and physics don’t lie.
 

GsRAM

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Regge,

As asked above, what are the specs on the trailer you are wanting. That will help us tailor our responses.

I'd suggest with your 1500 you look at trailers 7500 gvwr and under and 30' and under. If you do, your 3.21 geared truck will be fine. I would not spend the money on a gear swap with that excellent 8 speed.

Over that, your encroaching on 2500 territory in my opinion.

Good luck
 

ramffml

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I never said a word about gold air.

Numbers and physics don’t lie.

Numbers and physics don't lie, but you can still draw the wrong conclusions by:
a) looking at the wrong numbers
b) only looking at some of the numbers
c) not understanding what the numbers mean
d) ...
 
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