While returning from the weekends adventure (tranny service, 3200 spring & VERY slight VE tweak), I have a frontend vibration that seems to be more pronounced when cool, than after warmed up. Maybe 20 miles into my trip today, it mostly went away, even though the road got rougher than the first half

It happens on both ultra smooth brand new blacktop as well as the older concreted surfaces, so I don't think it was road related. Nor does it follow speed, engine RPMs, or anything else I can figure.

-Tires? I know bias ply's will bump/jump until warmed up, but these are radials and it took 20 miles! I've had bad belts also, but it NEVER went away...

-Balance? Why would it go away?

-Steering or Alignment? VERY, very slight pull to the left, all links check visually (yanking back/forth while off the ground), and steering is tight (until 90 ), but vibrations aren't effected by turns or straight

-Wheel Bearings? I checked them last week when I had the frontend up and everything was tight

-Shocks? Appear to be Monroe's of unknown vintage...

If I'm missing something obvious or there are known issues... feel free to point me in that direction!

 

Tire pressure even? try swapping the front tires with the rears and see if it goes away.

 

I'd thought of that, but the tires are mix-matched Load Range wise (front = E & rears = D) and I really wanted to keep the E's up front. I agree that this would would further thicken the plot & provide additional troubleshooting data, but I can NOT figure why it would come & go like it is if the tires were "warped"?

 

slight loose lug nuts that tighended up with heat


Flash.

 

All lugs on the front were freshly burped down weekend before last when I installed the sims... vibe was there both before & after the sims

 

Did you take an acorn-style lug nut and tighten two of them across from one another to line up the coins in the wheels with the coins in the hub?

For troubleshooting purposes, (unless you have 235s on the front and 215s on the rear) you should be ok to swap the Ds to the front for a while, at least til you get it figured out.

I will be watching this, as I have a similar vibration that is very random and unpredictable. But, between 78 and 83, it is quite smooth.

Daniel

 

I used to have the same problem at 68 mph. Finally went away when I rebuilt the front end kingpins / balljoints.

 

id get the front tires balanced on a "bubble balancer"
after the tires wear down they need to be re-balanced.
or if 1 weight falls off.

 

Nope... the wheels appear to hub centric (no coned area in the rims) and the lugs are flat on the backsides. *if* this were the case, I'd suspect the vibes to be continuous...

I'm still thinking it's a balance issue too...

 

Is it a SRW or dually D350? The dualles had coined fit rims stock, but in 14 years, who knows what has been done or switched out.

Daniel

 

Dually... that appears to be show room stock rim wise.

What do you mean by "coined"?