Vibration on braking

[autotech84601]

This 89 F350 SRW has had the brakes, rotors, drums, replaced front and rear. When i first got the truck i pulled the front diff out to have the inner shaft seals replaced as well as a front axle shaft as it was worn out. At the same time i also replaced the kingpins both sides. Since I was doing all this i might as well replace the rest right? Well did that to. Sway link bushings, steering gear box, inner and outer tie rods, drag link, steering stabilizer, I did it all. So when i step on the brake, I have a vibration, not in the pedal, but the front end. At times when I step on the brake real hard especially after driving the vibration causes the front cab to shake with the column yet nothing in the pedal. Any ideas or anyone have this happen to them? Thank you.

 

[riotwarrior]

Sounds like went all out...

Did you replace spring bushings and track bar bushings?

From your description it wouod be proverbial death wobble.

Is truck lifted?

Back off spring eye bolts all 6 bounce truck up down...climb on bumper. Retighten spring eye bolts to correct torque.

Most suspension must be at static rest height when tightened to torque for best results.

JM7.3CW

 

[autotech84601]

Sounds like went all out...

Did you replace spring bushings and track bar bushings?

From your description it wouod be proverbial death wobble.

Is truck lifted?

Back off spring eye bolts all 6 bounce truck up down...climb on bumper. Retighten spring eye bolts to correct torque.

Most suspension must be at static rest height when tightened to torque for best results.

JM7.3CW

I did not replace the spring bushings, but did replace the track bar bushings with energy suspension bushings. Should I have replaced the whole track bar? As far as spring bushings, is that a common issue and are the energy suspension polyurethane worth doing? When I removed the differential I did not do anything with the springs, only the track bar. I made sure it was good and tight when I reinstalled and man was it a ****** to put back in.

 

[autotech84601]

No the truck is not lifted, sorry forgot to answer that.

 

[kcconfq]

Did you check for disc runout before putting them on and align the truck after all the work was done?

 

[autotech84601]

I did check runout once the discs were back on, and the truck was aligned after all the work was done. The weird thing is that this slowly developed and then got worse and worse. Now that I would like to drive the truck as a daily driver I would like to get it fixed.

 

[Black dawg]

Since the slowly developed, sounds like you need to look stuff over again. Really sounds like rotors. Just because you dont feel it in the pedal doesnt mean it isnt the rotors.

 

[kcconfq]

Easy enough to put a dial indicator on it and spin them.

 

[autotech84601]

The rotors are brand new and replaced because I originally thought the vibration was coming from the rotors. They were checked for runout and found to be good.

 

[79jasper]

Check your wheel bearings.

Sent from my SAMSUNG-SM-G890A using Tapatalk

 

[Black dawg]

The rotors are brand new and replaced because I originally thought the vibration was coming from the rotors. They were checked for runout and found to be good.

Your descriptions and diagnostics are unclear. Did changing all these parts cause, change, or help the problem.

 

[autotech84601]

The only parts that I changed to help the vibration were the rotors. I did everything else because when I first bought the truck it was beat and the front end was hammered. I have been a German auto technician for 20 years and have little experience with domestic trucks. I am of the school that if one part is failing, I replace everything around it as well so I only have to do what I am working on once. The wheel bearings, seals and races were replaced when I first purchased the truck and the seals were replaced again and the wheel bearings repacked when I dismounted the hub assembly when replaced the rotors. I have about 2000 miles on these bearings as well and they are solid.

 

[Black dawg]

I have had problems with pad deposits on these before..did you really get after it and "bed" them?

 

[autotech84601]

What's strange is that right after replacement of rotors and pads on my test drive the vibration was exactly the same, nothing changed. I checked runout before I took it out on test drive as I had read that after replacement of rotors it should be checked and if found out of spec to turn rotors with an on the vehicle lathe to correct any issues. All mating surfaces between hub assembly and rotors were polished and cleaned. Rotors installed on assembly then onto vehicle. Runout performed before calipers were installed and after and found to be good.

 

[Black dawg]

Well if the problem was the same with new rotors that measured straight, it must not be the rotors.
Does it feel like death wobble? Driveshaft angle vibration under braking?

what was the runout measurement?