Death wobble (1 Viewer)

[starman]

This afternoon my 78 fj40 developed a major wobble/shimmy in the front end around 35 mph. Have had the tie rod ends replaced on the front. Can you guys give me some ideas on what to check first? Can wheel bearings do this? Preliminary pushing and pulling does not seem to show any slack on wheels or steering sector.

 

[mmmahhmatt]

Many threads to search on this topic.
Most seem to agree that it is caused by some loose component @ the front end. And alignment should be set to slight toe-in.
That said, my wobble was driving me mad. I had tightened and checked everything twice and three times with no help. I had just had my cruiser shop rebuild the front-end/ knuckles, and I installed new TRE's and aligned. Still wobbling and scaring the hell out of passengers and other traffic. When I finally just gave up, I brought the truck back to the shop who serviced the knuckles. Turns out one of the trunion berings gave out and was the culprit. Food for thought... -M.

 

[Poser]

What size tires are you running?


Make sure your shackle bolts are tight.


Make sure your u-bolts are tight.



Wheel bearings are not going to cause death wobble, unless the wheel bearing hub is ready to fall off the spindle, in which case, you missed many of the signs/noise previous to this situation.

 

[H2OBOSS]

Jack up the front end and double check your knucle studs top and bottom and torq to proper spec. Couln't hurt.

 

[peesalot]

x2 on the trunion bearings as the source. just replace them if they are old and reset the preload when you do.

 

[steverb]

you replaced the tie rod ends. did you get an alignment?

 

[jaacina]

My Land Rover Discovery had developed the death wobble. I fixed it by re-adjusting the swivel balls. The way you do it on the Rover is to pull shims out. I thought my FJ40 was similar, but it has been about 15 years since I pulled mine apart so my memory is a little fuzzy. So as the bearings wear out you pull the shims which push the bearings tighter.

I did this on my Rover. That of course was in addition to replacing worn bushings, tie rod ends and wrapping copper material around the bolts to make sure everything was snug. I used a weight scale to make sure the tension was correct. Drove like new afterward.

 

[starman]

Wasn't near as complicated as I suspected. My death wobble was due to the belts separating on the front drivers side tire - bf goodrich 33 9.5's. Fixed it by putting on the spare. New tires ordered.

 

[Hugh Heifer]

My wobble was caused by a worn out gear box. So worn that it would not hold fluid. It is currently on the floor in the shop as I work on the Saginaw install.

And there is always this

 

[flash02]

After rebuilding my front end I had a wobble at 50mph, this is what I found.

Loose right front Wheel Bearing

Loose Center Arm...Not very.

Toe was about an inch out.

Worn Steering Box.

After fixing the above the wobble calmed down but did not go away, and then I moved the front tires to the back and back to the front…no more wobble. You see when I bought the truck last winter the front tires were worn very badly on the outside but the backs had about 90% tread so I replaced the fronts w/ BFG 31x10.50. Perhaps BFGs are not as good of a tire as I once thought; now the entire front end has been renewed so I know there are no more old worn out parts to deal with.