We have a new to us 2021 Powerwagon with Carli Pin Top Suspension and Carli fabricated radius arms with a truck top camper. On our first off road camping trip we did some moderate rock crawling but nothing extreme, all at low speed and we never hit anything. Once we were back on the pavement it pulled left, which it didn't do on the way there. We took it in for an alignment at a shop that is familiar with Carli suspensions and he couldn't get it into alignment. I didn't take a photo of the results (and he didn't finish the alignment because he felt bad because he said the fix is going to be expensive) but I know one side was at 8 degrees and we think the other was around 3 or 4. He said the likely cause is broken plug welds and a spun axle tube. We have been trying to figure it out since then. There are 5 plug welds on axle housing on the passenger side of the differential housing. One of them (the one closest to the diff housing on the front side of the housing and close to the top) rocks (the one in the top right of the attached photo). The other four plug welds on that side axle housing seem solid and only one may have some oil leaking out but it is hard to tell if it is from us touching it or if it is oil leaking out. We don't see any evidence of problems with the plug welds on the driver side of the diff housing. We aren't convinced it is a spun axle tube. It is obviously costly to have the front axle removed and inspected. Is there anything else we should look at or do before taking it to a differential shop? Should we take it to a different alignment shop? We are in Northern California Bay Area. Thanks for any insight!! We want to get back out on the road and enjoy our truck!
Ram Heavy Duty Forum
Register a free account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members through your own private inbox!
Alignment Problems Carli Suspension
- Thread starter RssnMM
- Start date
Yes, part of the reason we went to him was that he works on modified suspensions and knows about the Thuren and Carli specs but couldn't get it within either. The right side was 8.1 and the left was 4.3. His worked on it and talked with us about it for at least 30 minutes and pointed out the possible broken weld. In the end didn't charge us because he felt bad that the potential fix is expensive.
We then took it into our local dealer since it is still on the powertrain warranty and they said there was no problem. My husband went into the shop with them and pointed out the one plug weld is rocking in place. They said they will tell their roving engineer about it next week but doubted it is covered or that it is causing our alignment issue.
We then took it into our local dealer since it is still on the powertrain warranty and they said there was no problem. My husband went into the shop with them and pointed out the one plug weld is rocking in place. They said they will tell their roving engineer about it next week but doubted it is covered or that it is causing our alignment issue.
With almost 4 degrees caster difference between the sides, its almost certain that a tube spun in the housing. I would park the truck on level parking spot, jack up the front axle and put in on equal height jack stands. Then take off the front wheels and measure the caster on each side. 4 degrees is enough to cause it to pull to one side, and if you adjust it differently on the axle, it will only pull the suspension down on one side and raise the other side. Also, it will put the rubber bushings on the axle in a constant bind. In other words, the axle will not twist to produce unequal caster, without breaking something...
I'm trying to understand how a potentially spun axle tube affects the caster. Or do I have two separate issues - an alignment issue and broken plug welds? There isn't physical evidence of the tube spinning within the housing but the welds are broken.
Ok, just in case you don't fully understand the configuration of your front axle, and to help with some terminology;
Caster Angle Basics: Caster angle is the angle of the steering axis relative to vertical when viewed from the side of the vehicle. A positive caster (the top of the steering axis leaning toward the rear of the vehicle) provides stability, helping the wheels return to a straight-ahead position after a turn.
Axle Tube Orientation: The front axle assembly is engineered with specific angles for the axle tubes that hold the caster and camber settings. When one or both axle tubes spin or rotate within the differential housing, it changes the position of the knuckles at the ends of the axle tube, which impacts caster.
Impact of a Spun Tube on Caster:
If the tube rotates forward or backward, it effectively tilts the steering knuckle in relation to the rest of the vehicle.
A forward rotation of the tube reduces the caster angle, leading to a less positive caster. This can make steering feel lighter but decrease stability, causing the vehicle to wander or "float" at highway speeds.
Conversely, a backward rotation increases the caster angle, resulting in heavy steering that may improve straight-line stability but can make low-speed maneuvering more difficult.
Consequences for Alignment and Handling:
Even a small change in caster can affect alignment and handling characteristics, leading to uneven tire wear, poor steering return, and difficulty maintaining control at high speeds.
A spun tube may require realignment or even axle repair/replacement, as it can cause ongoing issues with the front-end geometry...
Caster Angle Basics: Caster angle is the angle of the steering axis relative to vertical when viewed from the side of the vehicle. A positive caster (the top of the steering axis leaning toward the rear of the vehicle) provides stability, helping the wheels return to a straight-ahead position after a turn.
Axle Tube Orientation: The front axle assembly is engineered with specific angles for the axle tubes that hold the caster and camber settings. When one or both axle tubes spin or rotate within the differential housing, it changes the position of the knuckles at the ends of the axle tube, which impacts caster.
Impact of a Spun Tube on Caster:
If the tube rotates forward or backward, it effectively tilts the steering knuckle in relation to the rest of the vehicle.
A forward rotation of the tube reduces the caster angle, leading to a less positive caster. This can make steering feel lighter but decrease stability, causing the vehicle to wander or "float" at highway speeds.
Conversely, a backward rotation increases the caster angle, resulting in heavy steering that may improve straight-line stability but can make low-speed maneuvering more difficult.
Consequences for Alignment and Handling:
Even a small change in caster can affect alignment and handling characteristics, leading to uneven tire wear, poor steering return, and difficulty maintaining control at high speeds.
A spun tube may require realignment or even axle repair/replacement, as it can cause ongoing issues with the front-end geometry...
Agree it's got to be a spun axle tube, thats the only thing that would cause a 4 degree caster spread on a beam axle. The extra beefy radius arms possibly revealed a weak link. In the early 80's I worked at a well known frame straightening and alignment shop in Southeast Michigan. They always tried to give customers a good value, economy was terrible then. Thinking we would have used a chain wrench ( I have one with a 4' arm!) to rotate it until caster came back into spec then hit it with the MIG or stick welder. Or maybe disconnect the radius arm where it attaches to the frame and use a 4-ton between the frame and end of radius arm to rotate it back into position then weld. It only needs to move a little to change caster by several degrees. These approaches would be the most economical. Can always pull the whole assembly and send to a speciality shop.
werard
Active Member
PWclone0421
New Member
- Messages
- 6
- Reaction score
- 3
- Points
- 3
In my opinion this is why Ram put the different radius arms on power wagons. Radius arm suspension doesn’t want to flex side to side with 2 points on the axle and 1 on frame. All the twist is on the axle itself. With sway bar disengaged and rigid radius arms that won’t allow the 2 axle point to deviate from vertical with frame rail. The axle tube is under much higher torsion load. Definitely sounds like a twisted tube.