Shimmy When Braking?

[JFitzgerald]

I was hauling about a 1/2 ton of landscaping gravel this weekend and had to stop hard a couple times. When on the brakes hard the front wheels would start to shimmy (wobble). It would start real small and work up to a pretty good wobble. Drives great otherwise.



I believe there is no steering stabilizer on my truck. The ball joints were repaired by the last owner not too long ago. Tires are in good shape, no bad wear patterns.



Thanks in advance for any ideas.

 

[CToney]

Shimmy

I hope I can help. The same thing seemed to happen to my truck awhile ago. It was kinda intermittent and varied in how severe the shimmy would be. The problem was a piece that is in my rear drum that is used for adjusting the brakes had fallen into the drum and was causing my brakes to pulse unevenly resulting in the shimmy. Maybe pull off the rear drums to check and see if all the parts are in good shape and in the right spot. Be careful with the axle seals.

 

[sam peterson]

check the rotor runout. the shimmy may be caused by warped rotors. does it shake at all when it is empty? also make sure the caliper sliders are clean and lubed. that model has a tendency to freeze if the sliders are rusty. ----Sam

 

[scott4glamis]

w series ????? 1/2 ton of gravel( about six wheel barrows full) come on tell us the truth you had about 2 scoops from a front end loader... about 1 1/2 tons in the bed. . ???? ... shame on you the front end probably got a little light and all the looseness got multi plied and caused the vibration/ looseness in the front end..... been there done that, had 75 bundles of shingles , 10 sheets of 7/16 osb and 6 rolls of 30 lb felt in my truck, would have carried more but i have a tool box in front and had to put the tailgate down to fit it all... . didn't want to loose anything so

i went back for a second load , boy she road good

keep on ramming... ...

 

[JFitzgerald]

I'm not sure how the rear brakes could cause the front wheels to wiggle back and forth. You feel it in the steering wheel, but not the brake pedal, like you can with warped rotors.



It was honestly about a 1/2 ton of gravel. Only took up less than 1/4 of the space in the bed. It was piled right over the rear axle. I don't think the load had anything to do with it, other than the fact that I had to hit the brakes harder than if I were unloaded. Did ride nice.



I will check the brakes and steering, and order a steering stabilizer.



Thanks for the input.

 

[CumminsAholic]

we just bought a 89 4x4 with 350k... it does the same thing... shimmies, empty or loaded. I'm suspecting front rotors, you can't feel it in the brake unless you REALLY pay attention. Buy the steering wheel will go from left to right left to right pretty quickly. Not uncontrollably or a long ways, but enough to make it "shimmy". When it's time for new pads, the rotors will be turned or replaced, and I'm pretty sure that will cure it. BTW the 89's motor and transmission (auto) have never been touched. Well. . now it's got a tweaked pump, but that's all.

Corey

 

[JFitzgerald]

Originally posted by CumminsAholic

we just bought a 89 4x4 with 350k... it does the same thing... shimmies, empty or loaded. I'm suspecting front rotors, you can't feel it in the brake unless you REALLY pay attention. Buy the steering wheel will go from left to right left to right pretty quickly. Not uncontrollably or a long ways, but enough to make it "shimmy". When it's time for new pads, the rotors will be turned or replaced, and I'm pretty sure that will cure it. BTW the 89's motor and transmission (auto) have never been touched. Well. . now it's got a tweaked pump, but that's all.

Corey

The way you describe it is exactly what mine dones.



How many trucks (non-Cummins) have you heard of that can go untouched mechanically for 350K? I love that article in the last TDR about the million-mile truck. That is amazing.

 

[drives mopars]

i have the fix

now everyone of you guys do this



1 st if you dont have a rancho steering stablizer



go right now and get one

be careful it in position still allows shock

to go in and all the way out as wheels turn

and does not hit diff cover



i guarantee this will eliminate or improve



the shippy



my did what yours do and now mine does not!

best 55. 00 bucks spent on my truck



bill

ps summitt racing has them

i also put a motorcycle fork boot over mine

works great also only 1 is needed

mines a 93 4x4 dually, still shimyed after brake

work and no loose frt end parts

my friend a ford tow truck driver

cant drive his ford w/o one ,

 

[paccool]

Does it get worse when the brakes get a little warm? Take it out and get on the brakes hard a few times and see if the problem is the same or worse. If worse, I'd bet you have rotors that go out of round with the heat. I got mine real hot once and it would shake pretty bad whenever they got warm after that. It's a 2 wheel drive but should do the same in a 4x4. I had to replace the rotors, all is fine now.

 

[JFitzgerald]

Bill, Sounds good. I'll get the stabilizer from Skyjacker though. Just personal preference.



Stan, It does not seem to have anything to do with heat. It is slightly noticeable even during normal braking, just worse on hard braking. I don't believe I get in too many situations where I would build up a lot of heat in the brakes. There are no big hills here and I am allergic to cities.



Will buy a stabilizer first and go from there. Always had them on my Chevys with the solid front axles, and it made a difference.

 

[drives mopars]

its like i said

if you dont have one yet



then chances are its not something else



i know it will stop the shimmy period



this should end the problems you have

bill

 

[CumminsAholic]

Very good suggestion Bill. One of my buddies just put a napa one on his 93, said it made a HUGE difference. On our 89 though I know it's the rotors, I can feel it in the brake petal.

Corey

 

[mark93]

Hi Jfitzgerald.

I went through the routine you are going through, many others have too.

In my case hitting a bump in the road while braking made things worse.

Here is what I did.

1) Rotors turned and wheel bearings set to zero play: seemed to help until I hit a bump while accelerating from stop and turning at same time. Almost lost control due to shimmy.

2) Tightened steering box: No change.

3) Replaced drag link: Problem fixed.

4) Also replaced tie rod ends and tires for good measure.

Some component(s) is allowing "play" in the steering linkage-most likely the drag link on 4X4's. When oscillation is induced by braking with rotors that have some, but not excessive, runout, having worn out tires (or a tire with a bump in it), or hitting bumps the play allows too much freedom of movement and resonance vibration can occur. The vibration can become very violent.

With the engine running turn the steering shaft by hand at the steering box back and forth and observe the movement of the pitman arm relative to the drag link and the drag link relative to the steering arm on the axle. You can also check the tie rod ends but I don't think they go nearly as fast as the drag link.

 

[JFitzgerald]

Thanks for the informative post, mark93. The more I think about it, the stabilizer may be just a band-aid to dampen the unwanted movement of a worn component in the steering. I know my steering box is leaking at the input, which I am told indicates worn input shaft bushings. Gotta get around to replacing that box.



Not having spent much time under my Dodge yet, I am not familiar with the steering setup. Which piece is the drag link? Is it the link connecting the steering box to the knuckle on the axle?



Do you have a stabilizer on yours, or are you happy without it now that you have replaced the worn parts?



Thanks a bunch to everyone for their help, JFitz

 

[CToney]

Shimmy

They checked my rotors when I went to midas with the braking problem. They were perfect. As soon as they pulled the rear drums the problem was evident. It turned out I needed 1 new drum because the old one was gouged real bad. New shoes, cylinders, seals, and self adjusting mechanism on the problem side. I often thought of the steering stabilizer would help. Steering joint is gone again this time it will be a borgeson and my steering box leaks ie. bushings gone. where can a guy get a good box cheap and can a guy insall it himself.



CR Toney

 

[JFitzgerald]

CToney, NAPA has a rebuilt steering box with a lifetime warranty for about $200 - $250. Can't remember price exactly. I plan to install it myself and expect to regret it. Between the rusty bolts and getting the steering arm off the box, I am sure to have fun!

 

[drives mopars]

mark93

mark read my post



i ve been there done that



my was exactually the same as yours

hitting bumps while light on brakes

was worse w/ a load



i too thought it was a bandaid



i had very prof shop check all front and i did

too nothing was wrong rotors ok

tierods tight, toe ok

believe me , just replace or install the

stablizer , i guarantee to you too

that it will stop the shimmy f for good!!!!!!



now thats real clear!

i also changes the rims and new rubber

i spent a lot , nothing fixed it

until i put the stablizer on, period

 

[Matt S]

I have had my steering box out a few times as I'm on my 4th due to bad rebuilds. The hardest part is getting the pitman arm off. The best way is with a torch. All a sledge does is split the shaft. Good luck.

 

[mark93]

Hi again JFitzgerald.

You are correct about the location of the drag link.

My problem was fixed completely when I changed the drag link and I do not have a stabilizer.

I agree that at this time a stabilizer may just cover the problem.

 

[drives mopars]

1 more thing

a friend put a 99 or 2000 steering link



on his 93 fits perfect he said



2x bigger that borgenson



bill