One u-joint spins, other doesn't
Thread Starter
|
New User
Joined: Mar 2020
Posts: 17
Likes: 0
One u-joint spins, other doesn't
1999 f450 7.3 manual hubs. With hubs unlocked I can spin the front axle by hand and the drivers side spins freely but passenger only spins about one turn then stops. My mechanic says it is normal.
I have searched all over, if there is a thread I missed please post the link.
I had a significant jump to the right two weeks ago in 2wd, got under the truck and noticed this. Locked the hubs and truck drove fine. They found a toasted hub on passenger side and replaced both. Day before yesterday I had the same jerk to the right, but they couldnt replicate the issue taking it on 4 test drives. They said u joints seem ok, they look super rusty and zerks appear ungreasable.
Thoughts?
I have searched all over, if there is a thread I missed please post the link.
I had a significant jump to the right two weeks ago in 2wd, got under the truck and noticed this. Locked the hubs and truck drove fine. They found a toasted hub on passenger side and replaced both. Day before yesterday I had the same jerk to the right, but they couldnt replicate the issue taking it on 4 test drives. They said u joints seem ok, they look super rusty and zerks appear ungreasable.
Thoughts?
Cargo Master
Joined: Dec 2015
Posts: 2,913
Likes: 509
Hmmm... well lots going on here. First, if a lockout (ie locking hub) is truly unlocked you should be able to spin the shaft indefinitely, BUT really a better test would be elevate that wheel, hold the shaft and spin the tire. Some slight resistance can be normal in the side gears or lockout itself and if you're just reaching your fingers into the inner C and trying to spin the shaft you MIGHT not be able to provide sufficient force by hand.
Second, even if a lockout suddenly engaged while driving I don't see how this would cause the truck to pull. With an open diff (which you almost surely have) and t-case in 2hi that shaft could suddenly engage at 90mph and you really shouldn't feel anything....unless MAYBE the u-joint is seized or close to it.
However, external rust on a u-joint is meaningless and trust me, you want non-greasables - they last much, much longer, ironically
Without being there I don't know what to tell you....a sudden pull to the right could be a lot of things including bad shocks or steering stabilizer (if you had just hit an irregularity in the road), a questionable wheel bearing, ball joints, track bar or leaf spring bushings, drag link or tie rod, etc.
Second, even if a lockout suddenly engaged while driving I don't see how this would cause the truck to pull. With an open diff (which you almost surely have) and t-case in 2hi that shaft could suddenly engage at 90mph and you really shouldn't feel anything....unless MAYBE the u-joint is seized or close to it.
However, external rust on a u-joint is meaningless and trust me, you want non-greasables - they last much, much longer, ironically
Without being there I don't know what to tell you....a sudden pull to the right could be a lot of things including bad shocks or steering stabilizer (if you had just hit an irregularity in the road), a questionable wheel bearing, ball joints, track bar or leaf spring bushings, drag link or tie rod, etc.
Lead Driver
Joined: May 2003
Posts: 9,303
Likes: 48
From: Lyndonville, Vermont
steering issues are usually a bad ujoint causing steering problems...Pull the axles and check them. Also make sure wheel is straight ahead and you should be able to turn the axle on both sides...Driveshaft might turn.
Lock the hub and turn the tire on each side by itself.
Lock the hub and turn the tire on each side by itself.
Thread Starter
|
New User
Joined: Mar 2020
Posts: 17
Likes: 0
[/QUOTE]First, if a lockout (ie locking hub) is truly unlocked you should be able to spin the shaft indefinitely, BUT really a better test would be elevate that wheel, hold the shaft and spin the tire. Some slight resistance can be normal in the side gears or lockout itself and if you're just reaching your fingers into the inner C and trying to spin the shaft you MIGHT not be able to provide sufficient force by hand.[/QUOTE]
Huh, so the tech was incorrect that "it's normal" for one to not spin. As there are brand new hubs in there now, and are both unlocked, why would one not rotate? Thanks for the replys. Did some driving yesterday towing a trailer on dirt roads and the highway with zero pulls btw.
Huh, so the tech was incorrect that "it's normal" for one to not spin. As there are brand new hubs in there now, and are both unlocked, why would one not rotate? Thanks for the replys. Did some driving yesterday towing a trailer on dirt roads and the highway with zero pulls btw.
Cargo Master
Joined: Dec 2015
Posts: 2,913
Likes: 509
If one shaft is truly not spinning free of the wheel hub, the lockout is either defective or not properly installed.
If the t-case is actually not in 2hi or not disengaging the front driveshaft output this might also make a shaft harder to spin by hand
With the truck in P and 2hi and weight on all 4 wheels, try rotating the front d/s by hand. It should turn and you'll probably observe ONE axleshaft turn ('tis the nature of open or peg leg diffs). Jam a screwdriver in the side that spins and try again, then the non-jammed side should spin. If it does, this tells you both lockouts are FREE because you were able to spin both shafts while the wheels/tires didn't move an inch
If the t-case is actually not in 2hi or not disengaging the front driveshaft output this might also make a shaft harder to spin by hand
With the truck in P and 2hi and weight on all 4 wheels, try rotating the front d/s by hand. It should turn and you'll probably observe ONE axleshaft turn ('tis the nature of open or peg leg diffs). Jam a screwdriver in the side that spins and try again, then the non-jammed side should spin. If it does, this tells you both lockouts are FREE because you were able to spin both shafts while the wheels/tires didn't move an inch
Thread
Thread Starter
Forum
Replies
Last Post
muscletruck7379
Brakes, Steering, Suspension, Tires, & Wheels
2
Jun 16, 2004 05:55 PM
