I have a 1992 Ford F350 that vibrates at 60 mph or more whether I am accelerating or braking. No matter what I am doing it vibrates at that speed or faster. I haven't had this truck for very long so I don't know if it did it before all my changes or not until I drove it on the freeway from Idaho to Oklahoma.
Does anybody know what this could be?

What I have done to it.
New Shocks
New Sway Bar
New Tie Rods
Alignment
Steering Column Rebuild
ZF5 Rebuild
7.3 IDI Rebuild (top end)
New Rotors and Brakes for the front
Swapped a dually axle from a 7.5 460 1991 plus new brakes
All new fluids

 

How do the tires look? Also 4x4?

 

tires are practically brand new and yes it is a 4x4

just did a couple of tests

1. vibrations increase as speed increases after about 60 mph
no difference whether the truck is breaking, accelerating, or neutral
the vibrations match the speed

2. in neutral (stationary) I revved up the engine up to 3000 and no vibrations
occured (at about 60 mph in 5th I am about 2100 rpm)

 

have the tires balanced Im next to positive it will go away or at the least be nullified. You may have more issues but seeing its speed related I have to say tires. I know your name says idaho but if you are in MA by any chance you can hit up my shop and I will spin them up and lead them for free .. Only other thing I can think of or offer up is drive shaft. Check to see its balance weight is still welded on. If its missing, pass go and take that 200 to the drive shaft shop ( dont forget to check the U joints)

 

If it was the drive shaft I would think it would vibrate when he's driving the truck when he hits a certain rpm, not speed. Also I would think the universal would do the same thing, or vibrate all the time.

Correct me if I'm wrong.

 

Sometimes when buying tires and or rims, the place static balances the whole thing, instead of dynamic balance, which is a true / complete balance.

 

60 mph in any given gear will spin the shaft at a single RPM. The rear end is only one speed so RPM into the trans and and RPM out of trans are independent of motor RPM.

But if it shakes at 60 and gets worse as speed increases it could be on the list of checks. In neutral or braking its still spinning.



I have limited experience with universals failing. The 3 I have had quit all did different things and were full failures (so no comment on how why or what but tossed it out to check).

I really think its tires.... But I have lost that stupid weight off the shaft and had it shake at 45 + I have not seen it happen to anyone else to date. But people reading may show up to say they did too..

 

+1 on tire balance

 

Make that X3 on tires,, if it were the u-joints or bent drive shaft the vibration should come in at a lower speed.

 

Your 4 ....

 

Probably the tires... the 31" tires I used to have on my truck caused the same problem. They were balanced but the two front tires were so unevenly worn that it shook the front end going highway speeds.

 

if your tires are new/ish go back to the place you had them mounted and have them rebalance them. should be free- especially if you press the issue. you probably tossed a weight or something dumb.

also check all your mounts and bolts. put a wrench on things make sure they are tight.

while your under the rig check your ujoints for play (rotate the driveshaft by hand). and your transfercase bearings (shake the yoke side to side)

 

I just bought this truck and it needed a tire. I replaced the bad tire. I noticed that the truck will shake once it gets up to about 60 mph. I slow down and the shake goes away.


I had all the tires balanced and was told they are good. One shop said I needed a new tire. I went to get one and was told by another shop (both Big O Tires) that I didn't need a new tire and didn't want to sell me something I didn't need.


So do I need a tire or is it something else. I have read on here that it could be the ebrake or the ujoints.


Any one have any suggestions?

 

Check u-joints in rear drive shaft for play. How many miles on the truck? Your 2002 is different from the 87-96' trucks of this section of the forum, but vibration is vibration. Is your front differential actuator sticking? Common problem on your era truck. Causes the front driveshaft to spin despite the transfer case being in 2x4.

I've had an e-brake hang up before, the cable was rotted and caused it to stick. That caused a brake drag & repetitive clunking. I wouldn't have felt okay getting up to 60mph with that issue, but that doesn't mean it isn't your problem either.

Does the steering wheel shake or is it more of the whole truck? It would be wise to check for front end play too.