Bent/tweaked axle shaft/axle housing?

2004 Ranger regular cab longbed 4x2

A while back I was cut off on the highway while pulling a trailer. I was able to keep it relatively straight for about a quarter mile until the trailer pulled me around, jackknifed, then slid me sideways (driver's side first) at about 60 mph. Truck was drivable, but it had some issues I've been repairing as I get the cash.

I've had the truck on a frame rack, it checked out fine.

Additionally, I've replaced the following items:

-Rear spring hangers (bent)
-Rear shackles (bent)
-All shocks
-Rear springs (bent?)
-Wheels (bent)
-Tires

It aligns perfectly, and on straight, level pavement it drives fine until you get on/get off the gas. With each part(s) I've replaced, it's gotten progressively better, ie. no more vibrations, no more wild jerks from the wheel, so I replaced the crappy, badly-worn tires I had been waiting to do until I got everything else squared away, and now I have a new issue: (after which my mechanic thought it was bent springs, so those were then replaced, to no avail)

When accelerating, it feels like the rear is moving, causing the truck to turn to the left. When letting off the accelerator it returns to straight. This isn't noticable when coasting, nor is it present when braking, unless it's just after I let off the gas. Likewise, bumps alone don't upset the suspension, unless accelerating/decelerating. This isn't too bad when on surface streets, but at 60 mph, it gets a bit uncomfortable.

My question is, what could be going on here? It's more than a "pull," as the rear of the truck seems to "pivot" outward to the right under the above conditions. Everything in the rear is tight, as I checked it when I recently replaced rear springs. (it behaves the same now as before the springs were replaced) I've checked the tranny mount and it appears to be tight also.

I did have some seepage develop on the D/S of the rear diff cover shortly after the accident, which leads me to believe maybe the rear end is tweaked, and I'm hoping that maybe a new/rebuilt rear axle could finally resolve the last of my problems. (what else is there? LOL!) what do you think?

maybe a bent wheel but that should have showen up when you had the tires balanced

a bent axle shaft would be felt as a constant fluttering vibration.

a bent housing as a steady "pull" to one side or the other.

But unless you actually hit something while sliding (I.E. a curb or similar)
I don't see the axle housing getting bent.

AD

baddis: I replaced all four wheels and tires, as stated in the initial post.

AllanD: With each part, or pair of parts, replaced the handling/vibrations has/have improved/disappeared, leaving me with the pull as the only problem. I feel like I'm so close to having this truck completely repaired.

I did reuse the u-bolts and I understand they are torque to yield and shouldn't be reused, but money's been so tight that I didn't have a choice. Do you think that maybe there is enough movement at the axle and spring to cause that kind of shift? They are next on the list to be ordered.

At any rate, I didn't hit anything during the slide, it was in the middle of the interstate. I don't have the fluttering, and it's not steady. I'm at a loss as to what it may be, unless it could be something as simple as the u-bolts; I can't think of anything else back there I question aside from that as I've thoroughly looked it over many times.

How heavy was the trailer?

Even if you didn't hit anything, the trailer isn't going to let you tip over even if you wanted to. So you could have bent the tubes because you can't tell how much force it was putting on the road. If everything is straight as you say it is, I think it bend the tubes.

By the way, with functioning trailer brakes that shit don't happen.

I'm not sure of the trailer weight at the time, or empty for that matter, but the load was a skinny 23 ft. utility pole on a 16' flat deck.

If it was a car carrier type trailer with a wooden floor I am going to guess it weighed about 1900# empty. My sister had one just like it.

Very well could have tweaked the axle tubes or housing while being slide sideways against normal range of motion.

If the rear end is moving around, are you sure the U-bolts are tight and none of the leaves are broken?

Jspafford:That's the kind.

MAKG: The springs were just replaced, as stated in the initial post. I rechecked the u-bolts today, still tight and torqued.

I'm wondering if indeed the axle housing is bent, as it travels through the arc of the suspension cycle, it throws the truck out of alignment. Same when getting on or off the gas, it moves the suspension enough to allow it to travel to the point it's out of alignment. I need to find a shop that can check the axle housing, anybody near St. Louis that can recommend a shop? Hell, what kind of shop would do that? Machine shop? I've never had to mess with an axle or any of it's components before.

Thoughts, comments?

You need a frame and suspension shop. We have one around here in Ohio called "Nelson Frame & Axle" be on the lookout for something with that heading and they should be able to help you out.

Well, I looked in the phone book, nothing so far. I'm going to call around tomorrow and see what I can dig up.

I got a chance to drive the truck today. When I was out, I put it in neutral and let it coast a couple blocks; a couple turns, some bumps, no problems. -Steering is dead on, bumps don't seem to upset it, everything seems fine. When you step on/let off the accelerator, that's when the rear pulls to the left. I just don't get what could be going on, I gave the motor and tranny mounts another visual today, there's no movement, even when the clutch is let out and the engine torques the driveshaft against the parking brake. I can't see anything amiss, and everything leads me to the conclusion that it could only be the rear axle. I would think that if it were in the front suspension (2 wheel drive) that coasting along and having the suspension cycle would throw it off; it doesn't.

Is there a way to check and axle for true while on the truck, or if I'm going to that much trouble, should I just get a salvage rearend and throw it under there? ON EDIT: I just checked a local yard's online inventory, they have an 2006 with the same specs as mine and low mileage, will an 06 Plug and Play? I know it will fit, but was anything changed between 04 and 06 that would prevent a direct swap? ie. ABS and plugs?

I am pulling my hair out, and that's tough, because I have a shaved head!

a body shop should be able to hook you up with a frame machine.

baddis: A frame machine to check the rear axle housing? I've already had it to a body shop and put on the rack, everything checked out ok, at rest.

maybe the body shops i use has a different machine.

if you pulled the axle shafts and carrier you could put a strait rod through the housing to check it.thats what an axle shop will do to check it.