Ok, I work at a tire/alignment shop and I can't figure out what is wrong with this thing, so I hope your guys' expertise can help me out...>Had a customer come in saying his '89 F350 was shaking terribly when he went over 35, had had other shops check it out, they said nothing was wrong, but the problem still persisted.

When he came in, I saw an excessively loose drag link, so I thought that would be the problem, as well as the left side outer tie rod end had a little play. We replaced them, and did an alignment on it, and I had taken it up to 55 mph and didnt have a problem. However, he called yesterday telling me (quite upset) that he had just spent all this money and the problem was still there. So here's what I need from you guys because I don't know as much about these 1 tons.

It is a 1989 F350 Crew Cab Longbox 7.3L Diesel w/ and E4OD with a Dana 60 kingpinned front end....no play in the kingpins, and it looks like the play has been taken out of the steering (except for the box) its not lifted, but is a work truck. He says he can look out the drivers side window when its doing it and see the tire just wiggling back and forth like crazy.

Thanks a lot guys for any and all help you can provide

 

Wheel bearings, ball joints, tires could need to be roadforce balanced.

Try this: Grab the wheel, shake it up and down, any play is ball joints, shake it side to side-play means wheel bearings.

 

That's not necessarily true. It could help point to a possible problem in the areas you mention, but there should be a small amount of play in there even if everything is OK. The shop manual specifies about .001 of an inch play in the wheel bearings when they are reinstalled after servicing. Tightening them down to the point where there is no play at all will cause overheating and excessive wear.

I'm sorry, I don't know enough about what causes this wobble to suggest any proper fixes, nighthawk.

 

ok, I'll definitely check this out in the morning (I'm going on a test drive with him)....also, remember this is a KINGPINNED axle, no ball joints, so is the test method the same?....I have had and seen this problem with other half and three quarter tons with the "Y" link steering, but this is my first one ton so I'm kinda at a loss. I was thinking balancing too (since the tires are recaps) but that wouldn't make a tire shake left and right (visibly the worst gets around 3 inches in each direction)

 

Hmmm usually that kind of problem is either a tire issue or a panhard/track bar issue. You need to find out if it is speed dependant or action dependant. Like a tire balance issue is usually speed dependant so it always happens at the same speed but a suspension issue is generally action dependant like the death wobble panhard issue usually happens when going strait and hitting a bump. Or both for some I guess my truck shakes on fast easy left turns cause the right front swamper isn't exactly round, anyway.

Find out also if the shake is side to side or up and down. The typical panhard bar issue will shake from side to side and shake the steering wheel violently.

Testing Kingpins can be done much like ball joints, kind off. These have a spring in the top that keeps them tight, so if when you take that weight off if you can pry the tire up like with a worn ball joint then that spring is bad, either rusted solid or broken.

Did it align well? With the D60 Kingpin the the front will have excess negative camber if the kinpin, or more exactly the bushing is worn.

The kingpin really only carries the lateral load, the weight of the truck is carried by a tappered rollor bearing I guess if that bearing was bad it could move but I suspect it would allow the knuckle to grind against the housing. I would do 2 things to check, first look at the gap between the knuckle and housing on the bottum. That gap should be I think about 3/16 of an inch and taken up entirely by the seal. If the bearing is bad the knuckle likely would then be pressing against the seal and the seal would be damaged. Secondly take the weight of the tire, grab the bottum of the tire and shake it in and out, if the bearing has excessive runout the buttom of the tire will move in and out.

With retreads I would take a very very close look at the tires, not just balance but are they really round and true? If you have a tire balancer I would spin them and watch closely to also make sure they are round and true.

Hope this helps and I assume you have checked all the other basics, but take a very very good look at the panhard/track bar again, good luck, let us know what you find.

 

I vote a tire balance problem

 

Rotate tires see if anything changes.

 

Ohh another thought, take a close look at the shocks, could just be bouncing with bad shocks, and try and talk him into adding a steering stablizer if it doesn't have one or replacing it if it does, always a good thing on these trucks with all the track bar issues.

 

Ok, it IS a VERY BAD side-to-side shake (steering wheel about 1/4 turn back and forth.. I have the panhard bar off, the bushings look brand new....we just replaced the drag link and left side TRE. on tuesday, but he still has the same problem. Tires balance out fine, but that shouldn't be causing this anyways, seeming how it is such a violent shake left and right.....going back out to check for more stuff..

Thanks!

 

OK so the bushings are new but is the bar actually tight? Are the bolt holes elongated, are the brackets solid, etc? Does it have a steering damper?

Is it always at the same speed? What starts the shake?

 

Yea same question, what bushings where used as replacements?

If they are anything other then the stock type replacements its not going to work, the aftermarket neoprene etc etc type bushings that are simply pressed in by "hand" are not tight enough or dense enough material to take the strain.

Minimum have stock bushings pressed in, if that's not whats been done already, better yet and probably only way to permanently correct the issue is building a track bar utilizing heim joints at both ends. And if in doubt of condition, making sure the brackets for it at each end are rock solid.

 

Ok, so here's what I have done/checked so far.....I dont know what bushings they are (they do look like polyurethane, neoprene etc, definitely not stock rubber).

The bolt holes for the trac bar are not elongated. and everything was tight and I took it all apart, cleaned everything, even checked for breaks and cracks along the frame and x-member. Put loctite on everything as it went back on.

I did look at all the mounts.....they're just stock mounts, they look good, no cracks, breaks etc.

No it doesn't have a steering damper, I thought that more to be a band aid with a problem like this rather than a fix, but it would be a good preventative to put on afterward.

According to the customer, it can happen anywhere from 35 to 70, sometimes it will start from hitting a bump, or it will start by making a left turn. On my test drives, I've only been able to get it to do it in the 40-50 range.....

All tires have good air in them, and they are balanced.

 

Ok, so here's what I have done/checked so far.....I dont know what bushings they are (they do look like polyurethane, neoprene etc, definitely not stock rubber).

Had the same problem years ago with a older generation truck and yea it was lifted but the same applies.

Replaced the trackbar bushings with aftermarket type, best you could get at the time and it made the problem worse. Truck was just about undriveable in fact with them in there. Ordered a new trackbar from ford for it, it came in but didn't have the bushings in place. They ordered the bushings and had one heck of a time pressing them in, wrecked 3 IIRC to install the 2 needed.
That finally corrected the problem, I tried everything before that. New ball joints tie rod ends, replaced anything and everything that had even a hint of play in it but none of it helped.

Had the 6deg negative caster C bushings installed, new radius arm bushings, new TTB pivot bushings.

Me and a buddy, (a certified welder, I was no welder way back then) dropped the frame end track bar bracket down, down equal distance to the suspension lift (8.5") and solid braced it over to the opposite side frame rail. Removed the steering gear box welding in 3/8" plate behind it and around the frame at that point to further stiffen it.

I even dropped the front bumper off, I had made a bumper/brush/light bar out of a hunk of thick wall 12" channel. It must have weighted 100# or better itself. It had been on it for a couple years so I doubted it was the problem but I was trying everything.

It just hammered those aftermarket bushings to mush, they didn't have a snow ***** chance in Heidies to hold the axle in place.

Replacing those bushings with the stock rubbers did the trick, it never once suffered the death wooble after that as long as I owned it. I'm sure at some point it probably returned, few thousand miles later as the rubber worn down and softened.

Not sure if the type of heim joints you can by now days where available way back then, I doubt it, if so and had I known about them, we would have used those instead of the stock rubber setup. I would use them now no two ways about it.

No it doesn't have a steering damper, I thought that more to be a band aid with a problem like this rather than a fix, but it would be a good preventative to put on afterward.

Oh and yea I've always thought the same, steering dampers are a band aid masking underlying problems. The truck I mention above didn't have one and it had 40" tires on it, it didn't need one.

 

maybe bad u-joints or ding in driveshaft?

 

Ok thanks, I have the new one on order and it should be here in the morning....just a q but for what axle set-up did you need C bushings and TTB bushings?

Other than all of this, the only thing wrong with the truck is its a little bit off-camber, which requires an eccentric kingpin kit (its off by 0.2 degrees.)....I'll let you know how it all goes tomorrow!