Front Suspension Issue

BBSierra04 · August 11, 2011

I have searched and not found any posts with my exact issue. I have an '04 GMC Sierra 1500 Crew. Its a two wheel drive with about 130k miles and excellent service history. It has had factory '07 gmc six spoke 20's bolted up but is otherwise stock (not the wheels as the problem is still present with the factory 16s just not as pronounced). The stock shocks crapped out about 25k ago and that is when my issues started. I initially put very stiff KYB monomax shocks on it which actually did pretty well for a while and then I started noticing the ride was getting harsher mainly in the back. So we swapped them out for twin tube monroe reflexes which actually worked great as long as it was 50 degrees out. So those came off to be replaced with factory spec kyb gas ajust. This truck has the z85 setup on it so it has never been a cadillac but it was pretty subdued. With the addition of the monroes I noticed the front end always seemed very light and the wheels felt like they were bouncing violently. The Gas Ajust did not help this issue. So we went back and tried a light heavy duty style shock. I have these Gabriel Max Controls on it currently, which seem to be rebadged Delco Premiums. Problem is getting worse. I noticed the passenger side wheel hub was failing so I replaced it. Only to find out once it was off that while it was grinding a bit it wasnt really all that bad and had no noticable play in it. So I went through everything. Drivers hub seems OK, the rack was replaced at 97k and seems fine. Ball joints dont appear to have any play. The alignment has been checked and is said to be in spec but I am going to have the toe checked again. The only play I could find was in the tie rod ends but not in them but where they bolt to the spindle. They seem to move ever so slightly in the spindle when you push in the front of the wheel, not so much when you pull out. The movement I am seeing does not seem enough to cause the issues I am having. Along with the flutter the truck will actually bump steer if speeds are high enough. I dont think it is ahocks at this point as I have run the gammit of valving styles. These new shocks have actually all but fixed the beam shake issue this truck has always had. However, it can't be enjoyed as you never know when the front end is going to go crazy. I did notice today that the problem seems to increase as temps come up. Any advice or acceptable tolerance info is appreciated. The alignment shop did not notice any issues with tie rods etc. But I don't put too much faith in them checking it out totally.

jro909 · August 12, 2011

hmmm i have a similiar issue, my ride changed when i put bilstein hds and all terrain tires on...

Rons05z71 · August 13, 2011

what about all the rubber bushings in the front end? maybe they are old and dry rotted? As the temp comes up then they get really soft or something

BBSierra04 · August 15, 2011

what about all the rubber bushings in the front end? maybe they are old and dry rotted? As the temp comes up then they get really soft or something

I thought about that. I've tried to look at everything while she's still hot but just can't find anything that is causing this much feedback. The bushings are showing normal cracking but nothing major. I've even gone as far as driving next to the truck to see if I could see the wheels doing something they shouldn't be. Before the hub was replaced I did notice that particular wheel almost bouncing like a basketball which seems to have stopped with the new hub. My fear is it is just a whole bunch of little issues adding up to one big one. I think I have no choice but to replace the most obvious stuff like the other hub and the tie rods and hope that fixes it. Then rebuild the upper and lower control arms.

Thanks for the input.

BBSierra04 · August 15, 2011

hmmm i have a similiar issue, my ride changed when i put bilstein hds and all terrain tires on...

I've heard those HDs are a bit stiff. Thats the reason we pulled the mono max's. I know its not the shocks or the wheels as I have tried every combination of shock valving there is almost. And it still does it. Plus I have bolted up the factory 16s with stock size tires. I will admit this is better but only marginally. The truck will literally almost rip the steering wheel out of your hands on some bumps. Yet the rear end that used to jump over everything with the factory setup just soaks it up. Its irritating as my old 95 silverado took a 2/4 drop big street tires and wet 210k with only needing lower balljoints and tie rod ends. At a much higher mileage. Do you like those HDs?

jro909 · August 16, 2011

yes i like my HDs, the truck rides a little stiff no where near what it did when it had the stock tampon shocks on it but it seems to soak up alot more road imperfections and is it easier to control...it also rides very nicely when its under weight....as far as the steering wheel kicking around from what i've gathered thats somewhat normal for rack and pinion systems...and GMT-800s had alot of complaints over sloppy steering..i've driven newer cars with rack and pinions and they too also jiggle the steering wheel on some bumps but not as bad as my truck...i think the difference being the tire size difference and the fact that a truck weighs a bit more then a slowbalt

BBSierra04 · August 22, 2011

How does anyone like worn Steering Rack bushings for this. Got it to a different alignment shop Friday and they confirmed everything I noticed. It was all tight nothing that should be causing this flutter in the front end. They did find that the caster was way out. This helped but did not fix. They said the upper control bushings were cracked, which they are but no real movement. I noticed, while under the truck, that the steering rack bushings were not only very dryrotted they were pouring out from behind the mounting washers at different points. GM replaced this rack very recently and it appears the reused either my old bushings or the old bushings from the remanufactured rack they installed. I got it back on the ground and tried to turn the wheels to see how much the rack moves on its mounts. It moves quite a bit (1/8 to a 1/4 inch). I compared it to my wifes traverse that moves basically nill. My only point to question it is that despite this movement I get good input from the steering wheel to the wheels. A little steering wheel input and the wheels move a little bit.

BBSierra04 · August 23, 2011

do the Techs not answer questions anymore?

ChevyTech77 · August 23, 2011

Your rack bushings will move about what you describe even with new bushings.

I, myself, haven't posted back to your questions because according to your posts, everything that I have ever seen make this type of thing happen to your vehicle (shocks, wheel alignment angles and wide/low profile tires especially those mounted on wheels with a different backspacing than stock) do/did nothing to change/improve your concern. I'm sure you can see why I wouldn't have posted back then, right? Basically you've covered, and denounced, every possible cause for an issue like this that I have seen in nearly 20 years of working on GM vehicles and I specailized, almost half of those years, in front end (steering/suspension/brake) repair at a Chevrolet dealership. It's obviously over my head, so I wish you the best of luck and post back what you find that fixes it. Seems to be something that a LOT of people around here have seen out of their trucks as well.

BBSierra04 · August 24, 2011

ChevyTech77, sorry if my post sounded like I was pissed. I just wasn't sure if I was doing this correctly and thought maybe I was making the post in the wrong section. Thank you for your help. If you or anyone else has time I have new info. I checked everything again. Nothing is noticably worn. I asked an old mechanic I know and he felt like the drivers side spring was weak. He put his knee on the bumper and felt he could compress the driverside easier than the passenger. He also noticed the driverside is about 1/2 to 3/4 of an inch lower than the passenger (Thats where my fat ars is as well as 26 gallons of gas so to be expected). I don't know how I feel about this. His idea was to put those little helper pads in the coils to see if it helped. We only did one side and it seems marginally better but the coils or so spaced out I can't really install the things they way they are supposed to be. I just don't know that I buy the coils causing all this. Do you think it possible that every shock we have put on is just too weak for the truck? At one point I went to install OE Delcos but literally every set from 3 different dealers was leaking out of the box so we didnt mess with them. The KYB Gas-Ajust claimed to be OE replacement. A bench test against the factory shock seemed to confirm. However, the factory shock was leaking, though it was the best off all the shocks and was leaking the least. I know this isn't very scientific but its the best I have. The best the truck did was the KYB Monomax they were just so brutal I thought the dash and my kidneys were going to crack. However, the flutter was still present with those just not to the point of being dangerous. And these were on months ago so if something is wearing out it could be the same now with the monomaxs but I have no way of knowing. The truck doesn't float down the road, if anything these Max Controls are a bit stiff. However, I would not say the front end passes an old fashioned bounce test. Not one of the new shocks has though, except maybe the Monomax (mainly because you couldn't actually bouce it). According to the shock manufactures websites though this is no longer a valid way to check shocks because of the new valving systems. How, other than visually inspecting for leaks how can I check the shocks? I know I can take them to a suspension place and have them put on a shock dyno but this is stupid. For what I would spend I would just return them and buy Dual Ajustables and dial the thing in. There is no way this is this complicated. I have not had the 16's on it with these shocks so I will experiment with this again. Is it possible that all these crazy speed sensitive valves and crap in these shocks are actually having a reverse effect on the ride of the truck? I would assume the factory shocks are built in the same fashion to optimize the ride. If anyone has any advice I'm open. The alternative is to just rebuild everything. I just think that DA shocks, new ball joints, tierods, control arm bushings, steering rack ( incase it is something internally worn in the rack), tires, wheels and springs is a bit heavy handed of an approach to auto repair. I am not a mechanic but I know my way around a car and I have never seen anything like this.

BBSierra04 · August 29, 2011

Not sure if people are still reading any of my updates but as ChevyTech77 stated that my issue seems fairly common I thought I would share a forum post I found on a Dodge Ram forum. I realize the trucks are different but at the end of the day not that much. Also, the key point of the chasis' contribution holds as both are hydroformed. I apologize for the length of his post.

As many of you are aware, some owners of the 3rd Gen Dodge CTD CR Trucks have or are experiencing the dreaded "front end shimmy or wobble" after hitting a bump or pothole in the road. In many cases, the problem is directly related to bad tires or bad suspension parts such as ball joints, track bar, upper/lower control arms etc. Initially, I was not aware it was even an issue on the 3rd Gen trucks until my son, John Jr. (banshee) had it happen on his truck (with me in it) when were at WOT running down a two lane country road where I live. As many of you know, he is running the larger 315/75R/17 "B.F. Goodrich Radial All-Terrrain KO's". At the time it happened on his truck, the tires were worn, but not completely gone yet. They were "cupped out" on the edges of the front tires. We reported the shimmy/wobble to our Dodge dealership who told us they had several trucks doing the exact same thing, of which two of the trucks, still had the stock tires! My son ordered four (4) new tires and had our Dodge dealership install the new tires and do a thorough inspection of all the front end parts and components. Nothing in the front end was found to be defective and after the install of the four new tires the front end wobble/shimmy completely went away.

This problem with my son's truck got me to asking some questions and doing some research on this problem with the 3rd Gen trucks. I want to thank our Dodge Front End Technician, Mike Bryan, Sr. for all the help he has given me on this! Mike has been doing front end work for over thirty (30) years and is considered to be one of the best in our area here.

I want the members to know that as of today, we could find no specific Dodge TSB or related "bulletin" about this specific problem on the 3rd Gen Dodge CTD CR Trucks, 2003-2006. However, there is a Daimler/Chrysler TSB #02-003-03 out for all 1999-2003 Jeep Cherokees. The title of this TSB is: "Front End Shimmy After Striking A Bump or Pothole." Here are some excerpts from that bulletin:

SYMPTOM/CONDITION: The customer may experience a self-sustaining front end shimmy or vibration after the vehicle front suspension has struck a bump or pothole. The occurrence of this condition may be intermittent as it may be dependent upon the size of the bump or pothole that is struck.

REPAIR PROCEDURE: Replace the upper and lower front suspension control arms (total of four). Replace each respective axle suspension bushing as each upper control arm is replaced.

I realize that the front suspension on the Jeep Cherokee is somewhat different than the 3rd Gen Dodge CTD CR Trucks, however, there are also many similarities.

While talking more with Mike today about this, he told me they now have a customer with a 2004.5 Dodge CTD CR that cannot get rid of the problem in spite of changing out many of the front end components. This truck has stock tires too. Mike said he has talked with a Technical Rep. directly from D/C who also was a Dodge Technician and front end tech for several years before going to work as a Rep. Apparently D/C feels that there may be something called "frame rail frequency distortion" POSSIBLY contributing to this problem.

As most of you are probably aware, D/C now "hydroforms" their frames. Because of this design, it is felt that once the trucks tires begin wearing (cupping, uneven tread wear etc.) this vibration is then transferred into the frame and front end and apparently can actually get worse as it travels through the metal and components. This,... coupled with worn suspension parts etc. "aggravates" what is already there.

They feel that a possible way to combat this, is to fill the "hydroformed frame" with some type of foam, similar to what Ford does on the A-pillars in their new F-150. It apparently cuts vibration as well as noise. It sounds pretty wild I know,...... but I wanted the members here to know about it. Apparently the truck that our dealership is having that big front end problem with WILL get this treatment! Will it work??? I guess it is too early to tell right now, but I will keep you all posted.

What I take from this is once the truck gets any real mileage on it any wear is exagerated even if components arent shot. Another related post on this board stated that it felt at times like the frame was bending in the middle. Which I have just become used to with this truck.

BBSierra04 · January 13, 2012

ChevyTech77, I hope you are still on here. It has ben some time but I have a quick question. The problem started getting worse with the flutter and the truck started floating so I pulled the front shocks to find the Gabriel MaxControls had failed horribly. I went ahead and put Bilstein HDs on it based on EVERYONES recommendation and it was unreal for exactly 1400 miles. I am pulling them again this weekend to see if they have failed or just gone soft. I have noticed that the vast majority of GMT 800s I see rolling factory 20's have the torsion bar suspension with them cranked. I have the coil setup and obviously don't have the luxury of being able to change my spring rate like this. To your knowledge did GM not recommend running the 20's on the coil trucks. My thinking at this point is the HDs did fine out of the box as they were just stiff enough to reign it in but once they seated in aren't anymore. Its not getting worse but as before it is better when it 40 degrees outside. Thanks

ChevyTech77 · January 13, 2012

20's were available for an accessory on the C series trucks also. I'd say that your theory is most likely dead on, with the shocks going soft. Maybe see if Moog has a set of Cargo Coils for it? They have a slightly increased spring rate that may help.

BBSierra04 · March 7, 2012

Thanks ChevyTech77. The Bils are working, infact I reinstalled the 16s and problem solved. The truck is starting to show a small amount of wear in the ball joints now so a teardown is on the horizon and I will just replace everything. A local custom shop recommending putting new factory springs as they didnt feel the truck should ride poorly with the stock setup and 20s so maybe my springs are weak. I don't buy it though. So I agree with you. Apparently there are silver bodied Bils that are slightly stiffer than my Yellow HDs so I may just try it as I like the height the front end has always sat and don't want to risk raising the truck. The current HDs are a bit stiff with the 16s so my hope is the marginally stiffer silver bodies will fix everything. One last question, the truck had the "final" fix for the intermediate steering shaft issue but now 45K later has relearned its old habit. Was that fix not as "final" as GM thought? Or did the dealer not actually do what they said they did possibly? I was thinking about tapping a grease fitting into the outer shaft at the top as a fix.

Thank you for help.

ChevyTech77 · March 7, 2012

If it has the last replacement shaft installed, I have yet to see one fail. My guess is that you don't have the latest intermediate shaft or you have a lower steering column bearing going out that will cause a very similar sound.