4HI question
Cargo Master
Joined: Jan 2017
Posts: 2,243
Likes: 555
Superduty has heavy duty old-school u-joints where the axle meets the front wheel. They change their speed and kind of bind up and release when turned sharp. It can get bad enough sometimes to cause a sort of hop. Lighter duty vehicles and front wheel drive have CV (Constant Velocity) joints in the same place which turn nicer but aren't as heavy duty.
https://www.youtube.com/watch?v=WH8WjJ_ljjY
https://www.youtube.com/watch?v=WH8WjJ_ljjY
Hotshot
Joined: Oct 2006
Posts: 10,135
Likes: 7,941
From: Texas
well actually a cv is a long lasting joint, assuming theyre high qaulity and not chinese junk. its one main drawback is the boot that could be punctured or other wise damaged during offroad. with no boots to worry about, you could argue a ujoint is more rugged offroad but their torsion strength goes down hill fast when its turned off center while a cv maintains close to full strength i believe
Cargo Master
Joined: Jan 2017
Posts: 2,243
Likes: 555
honestly i think you could use a smaller cv and be just as good as a bigger ujoint. the joint and shaft have to handle the worse case scenario which is tire at full lock and engine full power. for simplicity lets say the joint will see 1000lb torq at full power and steering lock. you need atleast a 1250lb rated ujoint (figuring a 25% loss of strength at full lock. cv however could be a smaller 1000lb rated because you wont have the 25% loss
Hotshot
Joined: Jun 2003
Posts: 12,338
Likes: 4,349
From: SW VA
And either way, 4H with unlocked hubs is the same thing as 2wd...so what's the point?
Logistics Pro
Joined: May 2017
Posts: 3,523
Likes: 483
From: Southern OH
honestly i think you could use a smaller cv and be just as good as a bigger ujoint. the joint and shaft have to handle the worse case scenario which is tire at full lock and engine full power. for simplicity lets say the joint will see 1000lb torq at full power and steering lock. you need atleast a 1250lb rated ujoint (figuring a 25% loss of strength at full lock. cv however could be a smaller 1000lb rated because you wont have the 25% loss
Cargo Master
Joined: Jan 2017
Posts: 2,243
Likes: 555
ujoints. on either side of the ujoint , the shafts dont travel constant once its turned off center. i believe this is why u joints hop and bind. the travel on the stub shaft side is a eliptical speed rate as show in the video
and a ujoint strength goes down once its turned off center as well
Logistics Pro
Joined: May 2017
Posts: 3,523
Likes: 483
From: Southern OH
with open differentials a cv joint system shouldnt bind much in 4x4 . ya the front and rear is connected via tcase but theres linear speed on both sides of the joint regardless of angle. the turned front wheels may travel a bit further or shorter than rear wheels but i dont think it causes much binding like u joints
ujoints. on either side of the ujoint , the shafts dont travel constant once its turned off center. i believe this is why u joints hop and bind. the travel on the stub shaft side is a eliptical speed rate as show in the video
and a ujoint strength goes down once its turned off center as well
https://youtu.be/LCMZz6YhbOQ
ujoints. on either side of the ujoint , the shafts dont travel constant once its turned off center. i believe this is why u joints hop and bind. the travel on the stub shaft side is a eliptical speed rate as show in the video
and a ujoint strength goes down once its turned off center as well
https://youtu.be/LCMZz6YhbOQ
Cargo Master
Joined: Jan 2017
Posts: 2,243
Likes: 555
i dont know what we are arguing about here. binding aside, the guy who said cv joints are for lighter duty vehicles is completely wrong. a lighter rated cv could be used in place of a heavier duty ujoint
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Logistics Pro
Joined: May 2017
Posts: 3,523
Likes: 483
From: Southern OH
I know in the Jeep world that isn't the case at all, many Grand Cherokees came with CV joints in the Dana 30 front and swapping them out for U-joint axles is a common upgrade becuase they are way stronger, RCVs are the only CV joints that come close in strength and last time I checked they are over $1000 a pair for a Dana 30, I bet they cost double that for a Dana 60.
Cargo Master
Joined: Jan 2017
Posts: 2,243
Likes: 555
I know in the Jeep world that isn't the case at all, many Grand Cherokees came with CV joints in the Dana 30 front and swapping them out for U-joint axles is a common upgrade becuase they are way stronger, RCVs are the only CV joints that come close in strength and last time I checked they are over $1000 a pair for a Dana 30, I bet they cost double that for a Dana 60.
Logistics Pro
Joined: May 2017
Posts: 3,523
Likes: 483
From: Southern OH
dude i dont care what the jeep cherokee world does. i dont care what your opinion is. the moment a ujoint turns off center its strength goes down hill. at 90* its lost 50% . at 45* im sure its lost 25%. i already explained in black and white why a lower rated cv could be used in place of a higher rated ujoint. its very likely the jeeps dont want a common cv because the concearn of boot damage on the trail, which i mentioned already in the beginning. size for size the cv is a stronger joint.
Cargo Master
Joined: Jan 2017
Posts: 2,243
Likes: 555
well of course large tires make thing explode. hubs , axle shafts, transmissions , ring gears , tcase etc etc
what theyre doing is replacing a cv that wasnt meant for large tires, in favor of a ujoint thats probly 2x or 3x larger, to offset its strength loss at angle. atleast you should provide the entire story and not leave any details out
your a ujoint fan boi im sure. i like ujoints as well but i know theyre not a better joint. except to say that you never have any risk of blowing a boot 100miles from nowhere
what theyre doing is replacing a cv that wasnt meant for large tires, in favor of a ujoint thats probly 2x or 3x larger, to offset its strength loss at angle. atleast you should provide the entire story and not leave any details out
your a ujoint fan boi im sure. i like ujoints as well but i know theyre not a better joint. except to say that you never have any risk of blowing a boot 100miles from nowhere
Logistics Pro
Joined: May 2017
Posts: 3,523
Likes: 483
From: Southern OH
well of course large tires make thing explode. hubs , axle shafts, transmissions , ring gears , tcase etc etc
what theyre doing is replacing a cv that wasnt meant for large tires, in favor of a ujoint thats probly 2x or 3x larger, to offset its strength loss at angle. atleast you should provide the entire story and not leave any details out
your a ujoint fan boi im sure. i like ujoints as well but i know theyre not a better joint. except to say that you never have any risk of blowing a boot 100miles from nowhere
what theyre doing is replacing a cv that wasnt meant for large tires, in favor of a ujoint thats probly 2x or 3x larger, to offset its strength loss at angle. atleast you should provide the entire story and not leave any details out
your a ujoint fan boi im sure. i like ujoints as well but i know theyre not a better joint. except to say that you never have any risk of blowing a boot 100miles from nowhere
