[Scorpiodeee]

I have changed everything that I can think of on the front end. L&U CA’s, front struts, rear shocks, sway bar links, outer tie rods, brakes, rotors, wheel alignment, balance, suspension is much better except I STILL have a a vibration at high speeds (75 plus mph), AND most bothersome, I am all over the place when I go over raised bumps on the road. The truck feels TERRIBLE over hard bumps. Feels like I momentarily loose control for a split second.

ANY HELP IS APPRECIATED!

Thanks much in advance ! cm

 

[Sparky of NWO]

Don't assume that vibration and handling issues are related. Possible but not necessarily. Example, the handling my be a rack or wheel bearings and vibration my be a shaft. Did you do the work or have someone else do the work?

 

[Iconic_]

What suspension, tires and tire pressure are you running?

 

[Serenity Now]

How much lift do you have?

 

[rotorhed1]

As said, it could be many things. On an couple of trucks I had a tire separating. Check the tires for any odd wear patterns.

 

[FJtest]

More info needed:
1. What year FJ?
2. How many miles on the odometer?
3. EXACTLY what suspension mods have been added?
4. EXACTLY what tire make, model and size are you running?
5. What wheel width and backspacing are you running?
6. Are you running wheel spacers?
7. Has wheel rim runout been measured on all four wheels (via dial indicator)?
8. Have all the rubber bushings in the front and rear control arms been inspected and/or replaced (depending on vehicle age and mileage)?
9. Have the dynamic wheel/tire characteristics been checked on a Hunter Road Force balancing system?
10. Can you post the printout from your last four-wheel alignment?

As Sparky noted, the vibration and high-speed instability may not necessarily be related.

 

[mikey]

Take a deep breath, lets start with the simple stuff:

Check your tire pressure.
Did you have an alignment done, if so what were the spec's ( print out)?

Sounds like you tried the shotgun approach and missed.

 

[NyNomad]

was this vibration there prior to the lift? can you isolate it's origin to either the front or back?

 

[Matt Kurohara]

I don't know if it applies to us FJC guys (I would assume it does because I think we have the same diff), but I know that the needle bearing in the front diff on Tacos can cause vibes at highway speeds.

but more like what everyone else is saying, more info is needed, also is the vibration felt through the steering wheel or your seat?

 

[stephous]

I have changed everything that I can think of on the front end. L&U CA’s, front struts, rear shocks, sway bar links, outer tie rods, brakes, rotors, wheel alignment, balance, suspension is much better except I STILL have a a vibration at high speeds (75 plus mph), AND most bothersome, I am all over the place when I go over raised bumps on the road. The truck feels TERRIBLE over hard bumps. Feels like I momentarily loose control for a split second.

ANY HELP IS APPRECIATED!

Thanks much in advance ! cm

Did you lift your FJ? How much did you lift it? Front? Rear? Or is the FJ at stock height? If so what components did you install and who made them? Etc?

 

[Datajockeys]

Chunk of mud stuck on the rim?

Something wonky with the steering system (closer to the column)?

 

[IYAAYAS]

I installed a 3” Toytec 2.5” dia. Suspension on my FJ a year ago and it drive fine prior to alignment except when going over a bump. Going over a bump made it feel extremely loose and almost dangerous, kinda what you are describing. Might check to make sure they have your alignment set up properly.

 

[Kauri]

When you replaced the sway bar links, did you also replace the bushings that hold the sway bar to the frame? Sometimes that can help.

 

[Serenity Now]

Well the OP hasn't responded to questions, but it sounds to me like he has his suspension lifted too much and doesn't have any downtravel left, so he is going airborne momentarily after a bump. Also makes for a harsh ride when your control arms are at a severe down-angle like that.