New here so bear with me until I learn the ways off the site... Ok so bought a 1968 F600 with a CAT 1160 transplanted in the beast and it is a beast. The fellow who built this truck is a large truck mechanic and looks as though he did nice work. I am now going thru it and fixing what has not been done. This is a running and driving truck by the way. So far have found a fixed a vacuum leak for the brake servo which made a huge difference in how this thing stops... wired up the two speed rear end and just overall have been tiding it up a bit.

Now the problem... think it is called death wobble, at times on turning it has a severe issue witht he steering shacking and the tires wobbling left to right. figure it is king pins but thought I would ask for input here and see what you all have seen and know about this problem,hey maybe I will get lucky and it will be something simpler..
Thanks Jim

will post some pictures as soon as I figure out how and if I am allowed at this point

 

King pins, loose wheel bearings, loose steering linkage, steering box loose, bad front spring bushings, or bad front shocks are a few places to start. I would throw it on stands and see what's loose. Jack it on the frame to check the spring bushings.

 

Found the right front lower shock mount bolt was very loose. Fixed it but have not tried it yet to see if it helps.

 

Check everything over really well to make sure there isn't anything else.

 

Looked it over as well as I could still do not have a way to get it off the ground to check things without a load on it.

 

Warped front brake drums can also cause death wobble aka brake judder. Steering wheel vibrates so bad, it can be torn from your hands.

 

Does this truck have budd wheels or dayton? Budd wheels bolt on like typical wheel, Dayton is the old school type with clamps around the rim.

Once you are able to jack up the front, spin the wheel and see how true they run. If they wobble back and forth, loosen and retighten the clamps til you pull it in true(within 1/8"). Try laying a hammer down by the tire and watch it moved compared to the hammer. Adjust it til it barely wobbles.

Of course, you also need to check king pings and tie rods. These will also give you issues if worn.

 

It has Dayton type with the clamps, I check the tie rods ends for slop as in moment but not moving the wheels and they seem ok in that regard. My brother in law has a large bottle jack and we are going to try and get it off the ground today and see what we see.

The wobble we have happens on turns brakes need not be applied for it to happen. The steering tires turn left and right on thier own, seems to happen mainly with a right turn. was hoping finding the right front shock loose at the bottom attachment point is causing it but seems too easy...

Not looking forward to jacking this big beast up off the ground... but will check the Daoyton clamps today if I can make it happen.

Any word on kingpin replacement on this beast? have a couple friends who work on cement trucks and do side jobs.... what sort of cost you think I can expect for a job like this or is it one I can pull off.

 

We used to call it... The King Pin Dance.

 

OH and by the way it stops fine does not appear to have any warped drum issues.

 

The kingpin dance.... was affraid of that....

 

Don't just check the tie rods with your hand. Likely won't have enough power to really check it. Use a block and a long stick. Prop the stick up on the block and pry up on the tie rod end. If it moves, it's bad. If it doesn't, it's fine. Same with king pins(when you jack it up). Might take some persuasion with a long bar/stick.

If the PO was a truck mechanic, he likely knew how to mount Dayton wheels. But it doesn't hurt to check.

 

King pins aren't too bad with the right tools. They should still be readily available from a medium duty truck dealer. Meritor kit K537 is what you need, but if you can find a kit with steel bushings use that.
Basically, once the vehicle is blocked up on the front axle, pull the spindle nut and take the wheel and drum off as a unit. You may need to pull the backing plate as well, that should be six bolts around the spindle. There will be a cap on the top and bottom of the kingpin, remove those, and then remove the lock bolt holding the kingpin in place. If you have access to a kingpin press, it will make life easier, but with work you can drive them out with a flat pointed punch. Don't use a pointed punch or it will swedge the end of the kingpin and it will never come out.
Hopefully they don't need to be reamed, but if they do you will need to buy or borrow the proper size reamer. Putting it all back together is easy.

 

^^^I was wondering if they were std straight pins like the pickups.

My Mack has tapered pins and boy was that easy. After doing pickups for years, I was amazed how easy the big truck was.

 

So I have the hand tools to do the job, if I can get the right jack I am going to give it a try.