Sponsored

40's on 392?

richk225

Well-Known Member
First Name
Rich
Joined
Jan 16, 2018
Threads
108
Messages
1,850
Reaction score
1,407
Location
New Jersey
Vehicle(s)
2021 392Rubicon XR 2017 Jeep Grand Cherokee
Occupation
retired due to broken back
This was a 6-figure build I did a bunch of things to clear the 40’s… but only mentioned what was cut away. For the front shocks, I changed my spring rates, added AGM sliders, notched the frame and moved the lower shock mounts. I also needed to replace a few boots and install an HD Antirock in the front… but I tacked those at home.
It's A shame that a 392 delivered with tax is already a 6 figure build
Sponsored

 

richk225

Well-Known Member
First Name
Rich
Joined
Jan 16, 2018
Threads
108
Messages
1,850
Reaction score
1,407
Location
New Jersey
Vehicle(s)
2021 392Rubicon XR 2017 Jeep Grand Cherokee
Occupation
retired due to broken back
Well it’s a really good thing that I’ve never encountered one, which was really my point!

Mall crawlers stay on the pavement and, when they do go off-road, they avoid the hard trails. This doesn’t make them ‘less-than’ anyone else out here just because they’re too scared/smart to scratch up their 100k+ jeep.
Maybe they are smart enough not to get in over their heads?
 

richk225

Well-Known Member
First Name
Rich
Joined
Jan 16, 2018
Threads
108
Messages
1,850
Reaction score
1,407
Location
New Jersey
Vehicle(s)
2021 392Rubicon XR 2017 Jeep Grand Cherokee
Occupation
retired due to broken back
He’s a flat-lander that retired doesn’t make him an authority on anything. He’s a guy that that simply gets his kicks by showing everyone how special he thinks he is by putting down the people with better toys and a lot more money than he has. I’ve also noticed that he is followed by a small group of guys that are dumb enough to believe him… likely because they want to be him.

But what do I know… but I bet my education, pay check, and Jeeps are bigger than yours, combined✌
Just another flatlander who doesn't throw a bunch of negative crap back at you

I often lead group ride of 30 to 40 Jeeps and have lead a 60 or so Jeep ride. I have also been an instructor for Overland Expo. I teach how to plan multiple month off roading adventures and how to use mapping software like Gaia, Google maps, Onx. How to find dispersed camping and so on.

I had applied to be an instructor at Overland Expo West this year, but because of my father in laws death, I cancelled out. Sadly.

So not trolling, we just wheel a lot with a lot of Jeep people from all over. We have seen a thing or two
 

Mudduck

Well-Known Member
First Name
Jay
Joined
Dec 30, 2021
Threads
28
Messages
1,006
Reaction score
2,214
Location
Michigan
Vehicle(s)
2021 Willys 4door
Maybe they are smart enough not to get in over their heads?
@richk225 Ya know man, some fathers raise amazing men that become amazing fathers… And some apparently just beat off into a flower pot and raise blooming idiots… That is what we have all witnessed here in this thread, thanks to Phillip.
 

richk225

Well-Known Member
First Name
Rich
Joined
Jan 16, 2018
Threads
108
Messages
1,850
Reaction score
1,407
Location
New Jersey
Vehicle(s)
2021 392Rubicon XR 2017 Jeep Grand Cherokee
Occupation
retired due to broken back
@richk225 Ya know man, some fathers raise amazing men that become amazing fathers… And some apparently just beat off into a flower pot and raise blooming idiots… That is what we have all witnessed here in this thread, thanks to Phillip.
Well said!!
 

Sponsored

SSWIM

Well-Known Member
First Name
Sam
Joined
Jun 24, 2020
Threads
2
Messages
450
Reaction score
913
Location
Colorado
Vehicle(s)
Too Many
Wow just WOW. This thread went to pooooo in record time.

Sam
 

Tank2112

Well-Known Member
First Name
Darryl
Joined
Apr 12, 2023
Threads
4
Messages
123
Reaction score
103
Location
FL
Vehicle(s)
2023 Jeep Wrangler Rubicon 392XR, Custom Jeep LJ
Just keep in mind that if you go to 40” tires on 392 Wrangler, you will seriously change the on-road drivability. I don’t care what anyone says. I’ve been off-roading Jeeps for 20 years. Been down the road of trying to build on on-road Jeep that can run buggy trails.
Can’t have both.
The weightrotating mass and stiffer side wall of tires will dramatically affect the power and ride quality. Steering parts, knuckles, ect…will wear much quicker. It will vibrate after a few thousand miles if not right away.
If you off-road very difficult trails you risk breaking ring/pinion gears, drive-shafts. Questionable how long clutches in factory transfer case will hold up.
If you’re good with all that… go for it.

If you want larger tires for hard-core off-roading…. build an older Jeep so you don’t trash a $90k-$100k stock Jeep. Don’t forget a full roll cage.

There is so much more to it than simply fitting 40” tires to a Jeep.
 

Zandcwhite

Well-Known Member
First Name
Zach
Joined
Sep 4, 2019
Threads
10
Messages
4,410
Reaction score
7,868
Location
Patterson, ca
Vehicle(s)
2019 jlur
Just keep in mind that if you go to 40” tires on 392 Wrangler, you will seriously change the on-road drivability. I don’t care what anyone says. I’ve been off-roading Jeeps for 20 years. Been down the road of trying to build on on-road Jeep that can run buggy trails.
Can’t have both.
The weightrotating mass and stiffer side wall of tires will dramatically affect the power and ride quality. Steering parts, knuckles, ect…will wear much quicker. It will vibrate after a few thousand miles if not right away.
If you off-road very difficult trails you risk breaking ring/pinion gears, drive-shafts. Questionable how long clutches in factory transfer case will hold up.
If you’re good with all that… go for it.

If you want larger tires for hard-core off-roading…. build an older Jeep so you don’t trash a $90k-$100k stock Jeep. Don’t forget a full roll cage.

There is so much more to it than simply fitting 40” tires to a Jeep.
The wife's 39s have been holding up great to daily driving and wheeling for 10k miles so far. No vibrations, road trips at 85mph for hours at a time, not taking buggy lines but running trails like the rubicon, John Bull, etc without issues. People act like 37s are good to go but going any larger and the jeep will just disintegrate in weeks. Obviously there's more wear and tear the bigger you go but do we really think there's that big a difference between a 37 and a 40?
 

roaniecowpony

Well-Known Member
Joined
Dec 4, 2018
Threads
152
Messages
7,747
Reaction score
10,307
Location
SoCal
Vehicle(s)
2018 JLUR, 14 GMC 1500 CC All TERRAIN
Occupation
Retired Engineer
Well played! Your arguments are simply too good for me to continue ?‍?. I surrender and bow to the infinite/collective wisdom of this supremely experienced and extraordinary group.

Obviously I'm stupid because I mistakenly interpreted his post, from 2 days ago, where he said “…I just installed a rear Fusion 60 on my Jeep…” If there was any doubt left, I showed my stupidity again when he said he bought this new trailer (pictured below), in November 2023, and a noticed 5-lugs without a sign of any locking hubs or a drive slug. Golly, how embarrassing!
IMG_0052.jpeg


My bad, I forgot where I was and should have never brought facts into the conversation. All of your arguments have convinced me to immediately sell my Jeeps, grow a mullet, get a ? enlargement, and reevaluate my entire life.



Huzzah!
IMG_0184.gif
<iframe src="https://giphy.com/embed/QvrqQ1GUvqJWwefJCY" width="480" height="480" frameBorder="0" class="giphy-embed" allowFullScreen></iframe><p><a href="">via GIPHY</a></p>
 

SSWIM

Well-Known Member
First Name
Sam
Joined
Jun 24, 2020
Threads
2
Messages
450
Reaction score
913
Location
Colorado
Vehicle(s)
Too Many
Just keep in mind that if you go to 40” tires on 392 Wrangler, you will seriously change the on-road drivability. I don’t care what anyone says. I’ve been off-roading Jeeps for 20 years. Been down the road of trying to build on on-road Jeep that can run buggy trails.
Can’t have both.
The weightrotating mass and stiffer side wall of tires will dramatically affect the power and ride quality. Steering parts, knuckles, ect…will wear much quicker. It will vibrate after a few thousand miles if not right away.
If you off-road very difficult trails you risk breaking ring/pinion gears, drive-shafts. Questionable how long clutches in factory transfer case will hold up.
If you’re good with all that… go for it.

If you want larger tires for hard-core off-roading…. build an older Jeep so you don’t trash a $90k-$100k stock Jeep. Don’t forget a full roll cage.

There is so much more to it than simply fitting 40” tires to a Jeep.
To say there is no change would be erroneous. But to say seriously changed is also a tad inflated, I believe. Absolutely if not done properly it would change drastically. Done properly and especially with what is available in today's market the change would be minimal.

My 392 with 40s goes down the road extremely well. At 85 it drives great. No vibration. No shake. Just point and go. As far as being reliable. I will venture to say it is every bit as reliable now as stock.

No disrespect. I also have been off roading for a fair bit. Things have progressed rapidly in the off road world and it has been very beneficial to the end user.

Sam
 
Last edited:

Tank2112

Well-Known Member
First Name
Darryl
Joined
Apr 12, 2023
Threads
4
Messages
123
Reaction score
103
Location
FL
Vehicle(s)
2023 Jeep Wrangler Rubicon 392XR, Custom Jeep LJ
Stock 35” (33.75”) K02 tires are light weight (65lbs) and load range C for a reason. Adding a 90lbs, much larger tire with stiffer side wall, will definitely change on-road performance.
I’m just putting it out there for guys that haven’t had experience running larger tires.
Dana 44 can fairly reliably handle 37” tires over the long run. Sure, you can bolt on 40” tires, but it will effect braking, steering, stress on running gear… No way around that.
Remember lifting Jeep to accommodate larger tires also increases drive-shaft angles (wear quicker).
If I were going to dedicate to 40” tires, I’d install at least Dana 60/70 with manual locking hubs and 2wd option clutch-less transfer case.

Guy's running 40” tires, wonder what new 0-60 time is?

All depends on extended use of Jeep.
Sponsored

 
 



Top