front end shake

[natureboy300]

I have been struggling with a front end shake ever since I put my bulletproof steering and lift on. I am not positive if it was there before that or not as my tierod ends were wasted and had the death wobble before. The shake starts out at about 50mph and quits at about 65mph. I have jacked up my rig and had it in 4wd and brought it upto about 70mph but mostly kept it in the 55-65 range with no shaking going on, so it has something to do with road interactions. I have had someone turn the steering wheel while I was underneath to check for anything loose, and found nothing. I swapped front and rear tires and have had them balanced. And have checked for wasted u-joints. Possible for caster/camber change with the lift to cause this?. I wouldnt think so but but not positive.
Thanks in advance for any help.

Rich

[seahawkfan]

That seems a little fast for the "death wobble" but you can check out the WH website and read what they have about the wobble. It's a start anyway. Also check out Classic Broncos website.

This might help -

http://www.wildhorses4x4.com/product...obble/tech_faq

Jeff

[SonicDonkey]

I didnt see that you mentioned anything about your track bar. Are the bushings in good shape, bolts tight, bracket on the frame not cracked? Check these things out too. When I was wheelin a lot I would go thru a set of bushings every year. Castor and toe are also very important, I have always set mine around 5 degrees castor and 1/8-3/16 toe in measured off the front and rear of the wheel. Good luck, when you do get it figured out let us know.

Justin

[natureboy300]

Thanks guys,
The track bar is also from bulletproof, so there are no bushings to wear out. I have the WH trac-bar riser and the angles for the track bar and drag link are good. As for the mention of the death wobble, that is gone now, I had it bad at about 30 mph before I put the new steering on. I will keep trying to narrow it down. And will post up if/when I get it figured out.

Rich

[Familyman]

Where is the rig shaking from at 70 mph? 2 thoughts come to mind. Are the tires balanced? Have you balanced you rear driveshaft?? Pull the driveline and check all the joints. If they are all new or tight then check torque at the large yoke nut at the t-case and the one at the diff to ensure they are tight also. I know the first time I checked mine after I bought my rig the one at the t-case was loose.
That speed makes me think it is tire related or some other dynamic balance issue? What tires are you running?


Hope this helps, FM <><

[seahawkfan]

Yeah, what he said. Is it front end shake or is it a vibration? Does it happen when in gear and out if it is a vibration?

[Formerjughead]

you also might check the speed rating for your tires. Most larger tires are not meant to work well at those speeds.

Brad

[scubahawk17]

Yep....sounds like a tire issue to me..try rotating the tires...also go and have them balanced again. At the speed you spoke about I dont think it is a death wobble but a tire being out of true would do that.

[highlander]

A tire or wheel with a lateral imbalance will cause a shake at higher speeds and will still come up balanced on most machines. You will typically notice more when coming out of a turn on curvy roads at higher speeds. If this is the case you will usually notice a difference when rotating tires if the bad wheel or tire is on the back it much less noticeable.
I would also make sure your toe-in is right too little toe in can also cause some funny shakes.
Do you feel it in the steering or is the whole truck shaking?

[natureboy300]

I was somewhat leaning towards the same thing, a tire issue. I have had all 4 tires balanced and have rotated the fronts to back and vice versa. A few months ago when I first put the new steering in and first found the problem, I found a wasted rear driveline u-joint and figured I had it licked, but there was no change. Once the truck gets into the range of shaking sometimes it takes a little bump in the road to set it off. When it starts it is a light vibration then it turns into a shake that I can feel quite a bit in the steering wheel, then after about 70mph it drives like a caddy again.
Thanks for all the input and will take any more thoughts you can think off.

Rich

[kwspony]

How's the CV joint in the rear driveshaft? It can cause vibrations on the road. It is also very hard to grease. I usually drop it to grease it.

[Broncrick]

I was somewhat leaning towards the same thing, a tire issue. I have had all 4 tires balanced and have rotated the fronts to back and vice versa. A few months ago when I first put the new steering in and first found the problem, I found a wasted rear driveline u-joint and figured I had it licked, but there was no change. Once the truck gets into the range of shaking sometimes it takes a little bump in the road to set it off. When it starts it is a light vibration then it turns into a shake that I can feel quite a bit in the steering wheel, then after about 70mph it drives like a caddy again.
Thanks for all the input and will take any more thoughts you can think off.

Rich

Hmmmm, how are your ball joints? had the same prob once, ball joints it was. Sounds like you have done everything else
Rick-

[720Racer]

Front end bushings, wrong tires, unbalanced wheels, bad driveline, sounds like it's time for a frame up restoration. J/K

[natureboy300]

Front end bushings, wrong tires, unbalanced wheels, bad driveline, sounds like it's time for a frame up restoration. J/K

One of these days I will do a frame off, but it wont be on my current rig. At the house there is my 1970, my dads 72, my brother in laws 76 that my dad turned from a rust bucket into a rather nice daily driver, and a friend of the families 72. When we had our hunting ranch there were as many as 12 broncos at the cabin at one time. I always wanted to get a picture but always put it off, now the ranch is gone and I dont have the chance, thats a bummer.

NB

[Lars]

My take: get some information. Take it to an alignment shop. They can only set the toe-in, but they can measure the camber and caster. Should cost 50 bucks or less. Report back with the results. If the caster is less than 3 degrees (I'm guessing it is) then if everything else is solid, I'd guess that that's the place to start fixing things. Between rotating the knuckles back on my D44 and the extra degree I picked up with extended radius arms, I'm up to 6 degrees positive. I can run up to 100mph+ on 35 inch tires without the vaguest hint of shaking. In fact I did so yesterday, on the way home from SOB 11.