Rear end floating around??? Help!

[betz]

Hey guys,

(If you don't want to read the history, skip to the next section)
So, I just had a new steering gear box installed last week. The steering seemed to be about 75% better afterwards, but now it is getting horrible again (scary to drive on the highway, just changing lanes makes you think you're gonna die, let alone driving by semis and taking curves). I tightened the steering box 1/2 turn (thought maybe the box was going again!). And it sure tightened up the steering, but that SOB is still wandering like crazy! And it is getting worse very fast. Checked front end parts, even though it was just in the garage, and found that the front left idler arm has a little slop in it, but not too much. I also started to wonder if control arm bushings are bad, but I just can't seem to tell. Well, I found that if I grab the rear left wheel, while the van is on the ground, and rock it in and out, it makes two distinct noises. One is a thud, and the other is a knock. I get the same the when I rock the rear left wheel.

(Here's the question)
Anyhow, if my rear wheel bearings were bad, would it give the sensation that the rear end of my van is floating left to right, trying to get ahead of me (thing has a mind of its own). Because that's is what it feels like, and I think that is where the wandering is coming from...the rear end. Thoughts, advice, experiences?

Thanks In Advance

[Smiliesafari]

The axles are held in place inside the differential with 'C' clips. They (the 'C' clips) and the side gear shims are worn excessively.

[betz]

So, is the feeling I described the right feeling to associate with the worn 'c' clips and side gear shims?

[Smiliesafari]

That is correct.

[betz]

Well, I'm gonna bring it into the shop tomorrow and let my mechanic have it for the week. He does great work, but it's hard for him to find sufficient time to dedicate to my van. Hopefully he will be able to get it right by the end of the week. Sick of putting up with this wandering. But dang, she sure looks good with the lift and the tires! Thanks smilie, now I can head him in the right direction.

[GEJ]

I have been following this thread.It maybe also true the c-clips and side thrust are worn.But I doubt it creates the wandering you posted about.The one thing I haven't seen you ask about is the bushings in the leaf springs.If they go is would be more likely that is the problem.It would allow more movement of the rear end.The other thing I didn't see you ask about is if you have the sub frame back on the van correctly after you did the lift.It must be in the same position as it was before the lift.Measure across the van from the center line of the rear axles to the other side of the center line of the front axle.You drop a plum bob from the front axle and the rearend on a level floor or leveling the van with shims.If these measurements are not the same side to side,the sub-frame isn't in there square.The other thing to check is the sub-frame bolts.If they are loose or not torque correctly and the sub is moving around,well you can see where I am going with this.From what you posted I agree the side thrust need repairing too,but again,I don't believe that is the root cause of your wondering.Let us know what you find.

[mikedamech]

Yeah I'm with GEJ, The C-clips are relatively thin and I don't see wear on a 4 year old vehicle. If you move your wheels out a inch or so your van won't sway for that reason. Idler arms don't cause this ether, bushings will but, on a newish van? Larger tires cause faster wear on suspension parts but if you were me I'd forget your mechanic who may be led in the wrong direction from you telling him or her what people tell you on the Internet. Instead go to the most expensive Alignment shop and tell them the symptoms and I'll bet you they have the best resources to repair your van.

[betz]

Whoa, GEJ, you have made 666 posts. Thats almost as scary as driving my van.

Wow, some great points that you have made. Well, I actually had Overland DAN put the lift on my van, so I'm assuming he did it right and got everything square...then again, a couple weeks after the lift I had to replace the nut on one of the rear shocks because it friggen came off. A couple months later, the other one came off. He apparently doesn't use locktite? Anyhow, I put two nuts on each of them. So, who knows if he got the subframe on right. Also, I got the HD spring pack, so the leafsprings and bushings aren't all that old. In terms of the subframe being square, I will have my mechanic measure that out too, I just don't have the time.

Mikedamech, you say to forget my mechanic and goto the best alignment shop around. Well, I have had this thing aligned at 5 different shops, and none of them have done a satisfactory job. My mechanic doesn't actually do the alignments, he brings vehicles over to Pomps to get them done. But, he is actually a collision shop. He does the most amazing welding, frame pulling, body, and paint work that I have seen (well, second to most amazing I've seen). He also puts lifts on vehicles and sponsers a pro offroad race truck, and does all the work on that truck. So, he really is my best bet up here. And in terms of an alignment, the forum seems to say that the only way to get it done right is by someone who aligns the old fashioned way and gives it a negative 1/2 camber. I have yet to find the right shop, but will ask my mechanic tomorrow about a better reccommendation.

Bushings...I was thinking front control arm at first, considering the way my van leans when I turn the wheels one way or the other, but maybe it is a subframe issue or leafspring bushing issue. I wish my mechanic read this forum and these threads so that I wouldn't have to relate everything to him. I'm making up a list anyhow of things for him to check, so keep it coming.

[mikedamech]

Aloha betz, it sounds like your mechanic has all loose ends tied up, I'm certified in Alignments but would not do it on a customers vehicle. The angles go this way. Caster left 3.50 +- 1.00 right 4.50 +-1.00, Cross Caster (L-R) -1.00 +- 0.75, Camber 0.00 +- 1.00, Cross Camber (L-R) 0.00 +-0.60, Total Toe 0.00 +- 0.20, Steering angle -1.0 +-5.0. all in degrees.

[betz]

So, are these the factory spec angles, or is this the way that I should have someone align it? Where did you come up with those? And are those accurate for my 2005 Astro?

[mikedamech]

This is from Alldata and I have found mistakes but it shows that a 1/2 degree caster or camber is OK. For AWD anyway. I've had 14 Astro's and Safari's but never a AWD.

[betz]

so, would you recommend a negative 1/2 camber? Is there anything special to the way that you align your Astros?

[mikedamech]

I don't do alignments (very expensive equipment). I have used a tape measure and the wife driving forward and back to make the steering wheel straight but I go to the tire store, who don't pay there help much so I have returned to get it right. That's why I said for you to take it to the best shop. if your guy is smart he will deal with it one way or another until it is right. Tire wear is the most important issue, going in a straight line is important also. Some people will align differently than others but like I said expansive Tires, Wear.

[betz]

Cool, well thanks for your help. Im gonna add a little more to my list for my mechanic, and I'll see what he's gonna do for me tomorrow. Maybe I will spend some time in the garage with him while he works on it...heh, if I have the time. We'll see what he can do. I'm really anxious to get this ironed out so I can enjoy driving it.

[Smiliesafari]

A quick and easy test for wear in the differential is, while it is on the lift, grab the tire firmly and move it in and out. The play in the 'C' clips and/or side gear shims will be evident.