Agile RIP kit "gave" me death wobble???

[dirtanddogfur]

I had the same issue with my van. Same feeling you describe and there was a section of pavement (the Utah CO side of Suncrest Dr) that would throw it into full blown death wobble. At the time, my van had 12K miles on it and a fresh Quad van 4WD conversion.



I spoke at length w the guy at Quad Van. The odds of anything being worn out were low because it was basically a brand new vehicle. Ultimately, I put a dual damper steering stabilizer on it and problem solved.



Is it possible I am masking the problem? Yup. Van now has 55K miles on it and have not had a single incident of death wobble. I'll take it.



I live in Draper if you have any interest in checking it out.

[nemesisnight]

Originally Posted by MadScience

Sorting out a situation like this is really no fun at all. Here are a couple thoughts that went through my mind while reading this thread:

IIRC I have about 3 degrees of caster on mine. And while I'm sure more caster would make the van even more relaxed in terms of going straight, it's plenty to avoid any actual bad behavior. I have no issues keeping up with traffic and feeling fully in control.

If I was in your situation, I wouldn't throw money at more caster just yet.

I also have some bump steer, and once I had everything else in good shape, it really didn't bug me much anymore.

When it sways, which end of the vehicle is moving? And what is the first movement you experience? Side to side parallel to the ground, or a tilt perpendicular to the ground? Or is it steering input?

I'd paint witness marks on anything I suspected of moving in a way it shouldn't. In particular I'd mark all the bushing interfaces in the back. -- I say this because you mentioned an intermittent nature of your issues. When I had stuff moving around in the back, it could wedge itself into one position, bind up and be fine for days, then come unstuck and move around like crazy for a bit and then bind up again.

I assume you've talked to Agile about this in some detail? They really are a very expert source of information that you should leverage here.

Finally, your profile states that you're in Sandy UT. I would hope that there are some custom 4x4 shops not too far from there that would be capable of debugging this from first principles. Look for folks that do their own custom work, not places that will just install pre-engineered kits.

Yea, I have talked to Agile quite a bit about it all, we are stumped. When you say mark all the bushing interfaces in the back what do you mean, back of the bushing or rear end of the vehicle? In the rear it has all new leafs from Agile and brand new shackles and bushings so all good there. Front has brand new track bar bushings, new sway bar frame and axle poly bushings, ball joints and Ujoints are good, tie rod is new, drag link is decent but old and I have considered replacing it for the heck of it, not really sure what else to check to see if its loose.
I wouldn't say its completely intermittent, definitely happens always at freeway speeds but sometimes it feels better and isn't nonstop so probably based off road, and wind conditions, being passed by semis, etc. making long curvy turns seem to be a little worse but it often happens on straights too. Its hard to describe but it sways or swerves L and R and gets the suspension moving a little almost like a top heavy feeling maybe it reminds me of (I do have a high top but it shouldn't be that bad and feels nice and stable around town and off road). So then I have to try and over-correct and gently get it under control again, letting off the gas doesn't really help while it is happening much, sometimes hitting the gas is the same or can help even at times.

[nemesisnight]

Originally Posted by BroncoHauler

Good advice by MadScience.

I would also very, very closely inspect all brackets, and especially where brackets are welded to the frame or other brackets. There could be a crack that is not visible with everything not-in-motion as both sides of the crack are back in alignment, but driving movement could cause both sides of the crack to move independently of each other. A good, strong flashlight is your friend here, looking for lines of shadow (crack), and a person inside the vehicle moving the steering wheel back and forth is helpful too.

Don't give up.


herb

The track bar mounts and everything are pretty wimpy especially compared to what MG makes with his kits but it all seems to be in good shape. Ill have to inspect it closer again and try with someone cranking the wheel and see if I am missing something more subtle. My van is a 96 so maybe I am just getting a little flex or something with the extra lift, I have no idea.

Don't judge all the red dirt and mud, Just means I use it alot and live in Utah, that stuff gets everywhere, lol.



Drag link where it meets the pitman doesn't look pretty but it feels pretty tight.

[shenrie]

Originally Posted by nemesisnight

...and I don't know why I seem to be the only one having this, the RIP kit usually fixes these issues for people.

I still have the issue your describing. its definitely not the death wobble ive seen others talking about. I call it swimming and it only happens at high speeds. to me, its like a perpetual overcorrect for late steering input once the van is disturbed by passing a semi or heavily rutted roads.


mines a 03 Quigley with the c-channel control arms. im on 35's with agiles latest edition valved fox shocks, single steering damper, and the moog springs that provide the 1.5-2" lift. those items helped a ton from how sloppy my rig was upon purchase, but it still "swims" at the higher speeds. I plan on getting my rear leafs replaced once money allows and get rid of the 3" block. only other thing I can think of that I changed was the pitman arm that hangs lower as per ramseys recommendation. I also attribute some of my steering slop to the remanned steering box I was forced to buy locally when my original one broke.


have been keeping an eye on this thread. hoping I can benefit as well.

[nemesisnight]

Originally Posted by shenrie

I still have the issue your describing. its definitely not the death wobble ive seen others talking about. I call it swimming and it only happens at high speeds. to me, its like a perpetual overcorrect for late steering input once the van is disturbed by passing a semi or heavily rutted roads.


mines a 03 Quigley with the c-channel control arms. im on 35's with agiles latest edition valved fox shocks, single steering damper, and the moog springs that provide the 1.5-2" lift. those items helped a ton from how sloppy my rig was upon purchase, but it still "swims" at the higher speeds. I plan on getting my rear leafs replaced once money allows and get rid of the 3" block. only other thing I can think of that I changed was the pitman arm that hangs lower as per ramseys recommendation. I also attribute some of my steering slop to the remanned steering box I was forced to buy locally when my original one broke.


have been keeping an eye on this thread. hoping I can benefit as well.

Good to know I am not the only one experiencing this, I thought I was alone!!!
I wonder if mine is a bit worse since I have the high top.... It definitely is enough to be scary for me and make me worried that I could sway into another lane slightly at times and hit someone when its close quarters. My steering is also sloppy and loose but always has been and I didn't have any of the high speed issues until I added the full RIP kit, it always felt surprisingly stable at speed, high winds, etc, wouldn't even budge going by a semi, but the shocks were horrible and the rear leaf springs de-arched and man was it rocky off road. Not anymore though, now I dread it at speed and it feels great around town.

Do you have any idea what drop Pitman arm you used and how much of a drop it was? dropping the drag link seems like it might help with bump steer if that's even what I am getting but then my track bar is still at the higher angle, so are yours at different angles then if you did a drop Pitman arm??

[shenrie]

nope, not alone. ive been fighting this since I purchased the van in 2012. its at least bare able now. the drive home from georgia was hell, lol. about wadded it up a few times.


having our motos on back does make it worse, but just a little. so not sure a hightop would be any different. our rear springs are just staring to arch the wrong direction. definitely need replaced.


the pitman drop was about 2-3". arms are definitely at different angles. as soon as I need to replace the lower im looking for a straight one instead of the weirdass curved one I have now.





I was surprised when I saw the title of this thread. the agile stuff I got did make a huge difference for the positive for me. im sorry you went the opposite direction

[nemesisnight]

Originally Posted by shenrie

nope, not alone. ive been fighting this since I purchased the van in 2012. its at least bare able now. the drive home from georgia was hell, lol. about wadded it up a few times.


having our motos on back does make it worse, but just a little. so not sure a hightop would be any different. our rear springs are just staring to arch the wrong direction. definitely need replaced.





I was surprised when I saw the title of this thread. the agile stuff I got did make a huge difference for the positive for me. im sorry you went the opposite direction

Interesting, definitely a much different setup than my 96 Quigley. Yours seems like it would have alot less bumpsteer, my track bar mounts alot lower on the axle and I have much more angle on that and my drag link. I might just see if a fabricator can come up with a completely new steering setup. Heck most agile converted vans don't even run sway bars period so maybe starting from scratch would be better than Band-Aids.....
I still love Agile and John has offered all the help he could, and my products from them are very nice. It just opened some skeletons I didn't want in the process I guess. I felt bad wording the title that way but it was the truth and meant to bring light the unforseen issues I wasn't expecting not related to the suspension itself. I seem to not be the norm for sure though, so maybe this older design doesn't play as well with the extra lift.

[TomsBeast]

Sorry for being way late to the party on sway bar bushings.


Mine went bad, after researching the truck forums, it seems like the lifted truck guys get 10k-20k miles before they have to change them. Some guys were complaining about the urethane bushings as well. I hadn't seen the thermo plastic Moog bushings bad them.



My solution was to throw the baby out with the bathwater, I ditched the light steel saddles and rubber, replacing them with an all inclusive delrin bushing block.


I've had them on for about 15k miles, still holding strong, with no harshness, or rattles, and no appreciable wear.

[carringb]

Originally Posted by nemesisnight

I wonder if mine is a bit worse since I have the high top....

Most likely. Basically, with the angle of your drag link, every time the the driver side of your van compresses, including from body roll, it's shoving your steering to the right. Which of course exaggerates the roll more. But then you yank the steering to the left to compensate, and as soon as the driver side suspension starts unloading, it will pull your steering over the left even further. Rinse and repeat. The worn gearbox make it's worse because you're always late to game, amplifying it further.

I still think that with you geometry, you need to increase roll stiffness as much as possible. You've made a decent improvement to the front, but with the high CG of your top, a rear sway bar will make pay huge dividends.

I have a 1.5" Hellwig rear sway bar intended for 30' motorhomes. It works great for me. It would be nice to have a disconnect on it for off-road driving, but I haven't found an off-the-self kit large enough for that bar. My van is so rear biased anyways, the back is always planted, and it lifts a front tire instead.

[shenrie]

^^^ good call. Guess I didn’t think about it since it wasn’t mentioned, but I found a big swaybar on the back of a f450 flatbed (junkyard find) that I installed. Pretty sure I did it prior to the rip parts as well. Definitely helped with the freeway swim. Also helped considerably with the wallow from driveways and uneven intersections around town.

Got me thinking about the high top weight as well. What do you guys think is the weight difference between my 18” top and the 24” tops that people are using? I know people install cabinets and what not up there, but we have all our bedding and we keep our trip bags up above the oem roofline. With the bed frame, lift mechanisms, and all the other crap we keep up there on trips, it’s gotta be close to a wash.