Hey all,

Have a 2000 Jimmy 4.3L, 4L60e, 2wd with 109k miles. At highway speed I'm getting a shaking that has been getting progressively worse over the past month. At first it was only bad at ~70mph. Now it's pretty much any speed over 60. It seems to be coming from the front end of the truck, but I can't quite tell if it's driver's side or passenger or both. My wife DID say she felt it when riding passenger side.

So far I've changed the following or inspected it and found it to be good, not necessarily because of this issue, but because they actually were bad or needed inspecting. I was just hoping the problem would go away afterward, lol.

1. New steering linkages. Idler, tie rods, centerlink. Pitman is solid.
2. New upper and lower control arms with ball-joints
3. Shocks are in great shape, (they still dampen nicely)
4. Motor mounts are good
5. Alignment was performed
6. Wheels balanced
7. No shaking in the steering wheel
8. Wheel bearing hubs replaced about 10k miles ago with Moog hub bearings
9. Removed drive shaft, u-joints were were a little stiff, but no hang ups and moved freely.
10. Transmission mount good
11. No engine codes, engine runs smoothly for a 4.3 😆
12. Tires are in great shape and show no uneven wear or feathering
13. Rotated wheels to see if it changed anything to no avail
14. No excessive slop in the steering box

Guys I'm lost. I can't figure out what's causing the damned shaking. And it's getting worse, lol.
​​​​​​this has stumped me. It can't be steering because I'd feel that in the steering wheel. Steering wheel is solid.

If you guys have experienced this and have any ideas, please share. It would be very appreciated!

-Astro

 

You can check for out of round by jacking a wheel up 1" and laying a 2x4 against the tread and slowly turning the tire. Then lay the 2x4 against the side of tire and do the same thing. Make sure the lug nuts are tight, first.

You can check alignment using a string. Tie the string to a back wheel and run it to the front and turn the steering wheel so the front and the back of the tire are the same distance (parallel) from the string. Now make the same measurement to the other side. If that tire is not parallel, you need an alignment.

 

So right now im experiencing this same thing... thats why im in here today... my shake shows up around 40 and gets pretty bad around 55 or 60... havent gone any faster with it like this 🤣🤣...
so anyways, about a month ago i noticed my p/s front wheel bearing making alot of noise... i got new cv axles and wheel bearings... sway bar bushings and links... after a couple days on the new stuff, its vibrating real bad... i shake it down and see my idler is worn out, so i change it... my ball joints and tie rods are less than 6 months old and the moog pitman arm is the same age... when i install the new one the front right tire is toe'd way out and i adjust it back to "close enough"... the vibration hasnt gone away or gotten any better...
i have a couple issues though... my shocks are old and the one on the p/s is dead (my next week buy) ... when i was doing the control arm bushings i noticed that theres a big dumb crack in my frame where the lower control arm mount is... this is common on zr2's idk if u have a zr2 or ls/lt but... look for that. I know when it happened to my d/s it was really bouncy and drifted side to side in the lane... because ive changed everything and adjusted the alignment, idk where to look... idk if its the crack in the frame or the cv axle... the idler arm looked like maybe someone put it back in the box and returned it... it was still tight, but it was missing the castle nut and cotter pin... so that was kinda sketchy too...

 

Check the frame around your lower control arm mounts on both sides... you have to lay down under the truck and look from inside the frame... my d/s crack was visible from the outside looking in, but the p/s is only visible from underneath and from the inside... you cant even see it outside... check your cv axles... i plan to take my cv axles out on sunday and see if it still has the vibration... ill def keep up with you and let you know what i find... maybe it will be of some help

 

Do NOT test drive without the CV axles in. That axle nut and stub shaft of the CV axle is what keeps the rotating portion of the hub attached. You know, the part that has the studs that the lug nuts attach to. You will lose one or both tires while moving even at slower speeds. I sure hope you read this post before trying this.

 

🤣🤣🤣 i had heard that but i wasnt sure how long before the wheel actually falls off 🤣 i think one of the old ones went in the garbage truck yesterday morning... i have atleast one old one that i can break the stub out of... im only having this vibration on the p/s, so well start with just the one... worse comes to worse and ill get a pair of 2wd bearings 🤷‍♂️

 

Also, idk why it says "beginning member" i been a member for 4 years... the whole time ive owned the truck... when i bought it, i came here for all the answers 🤣🤣💀

 

The "member" tag is counted by number of posts, not the length of time you actually have been a member...I think.