Front End Vibrating

['70GMCStep]

Got a question for you all.

Just installed a new front spring on the '65. (I should have put new springs on the front when I redid the front with new control arms, discs etc). I had it aligned but after it was aligned I stepped on it, and then around 50, it started in. I have had this guy align my stuff many times, and he does great work.

The tire is fine, no bent wheel or weights out of place. Am I looking at new ball joints? These new control arms from CCP were put on last summer, and the truck only has about 300 miles after the front end rebuild I did. The ball joints came installed in the kit.

What do you all think I should do? I'm at a loss here.

Thanks,
'GMCStep

[markeb01]

Did you replace your idler arm when you did everything over? A worn idler arm allows the right wheel to wobble around (normally at speed) while the left side tracks straight, being connected by the pitman arm directly to the steering box.

It would also be worth taking it back to the shop for a recheck. He may have done it many times, but humans do make mistakes and perhaps an adjusting nut was left loose, or something else may be wrong that he might not have been looking for.

['70GMCStep]

Ah...I didn't do the idler arm when I redid the front end. I bet that's it. My buddy over at the alignment shop has my truck and is going to drive it, but that makes good sense.

While I'm at it, is there anything else that I should be looking for that could be replaced with the idler arm while I'm on this? (steering is next, but can't do it right now)

Thanks for the advice, I appreciate it.

'GMCStep

[markeb01]

If they are original, I'd also have him check the tie rod ends to make sure they don't have any excessive play. A little bit at the idler arm, and a little bit more at each tie rod end can add up to a problem. You might also check the wheel bearings to make sure they are properly tightened, and the races were fully seated. A problem here should be very obvious on inspection. A worn steering box doesn't usually result in vibration, it's more likely to cause sloppy or difficult steering. Front end vibrations are generally caused by the rotational forces (wheels/tires out of balance) or they tires are either not properly toed in, or don't remain properly toed in, resulting from worn parts.

Once in a while what seems to be a front end vibration can also turn out to be a bad u-joint in the driveline.

['70GMCStep]

The only two guys that I trust to do what I can't both think that it is nothing in my components. After both driving the truck, both know that at around 50 mph it starts to violent vibrate. Nobody suspects the idler arm or any other thing I have set up as a problem after looking at it all.

What the alignment guy and another shop I trust that I have asked say now is that it must be the tire/wheels. I'm going to limp it over to the third shop and see if it is just that simple of a problem. (surely not) It did sit in the garage for a while until I had a Saturday to tear into it. We'll see. The only other thing I haven't done is check the wheel bearing and race. Nobody down here is saying "ball joint", but I have two new spare ones on the shelf in the garage.

Am I on the right track? I feel like I'm going

[Russ65C10]

Given how long the truck has set and the quaility/age of the tires you might have a tire that is seperating or has a flat spot due to how long its sat around...

['70GMCStep]

Third shop now is reporting they don't know either. All say front end is great with new parts. Tires are going to get some kind of stress/balance test. I think it just helps typing this out for my stress level.

'70GMCStep

[TR65]

70Step,

If you have not done it swap front wheels with rear and see if anything changes. As Russ says, could be a bad tire.

Another thing you can do is check the runout of the tires by spinning and using a screw driver blade or other tool as a guide to see if there is a bulge in the tread, indicating separation.

Good luck,

TR

[Slow Build]

What kind of vibration (Is it on one side only, both sides at same time or does it oscillate side to side)? Do you run a sway bar? I'm guessing you have new shocks. Just trying to get more info.

[Captainfab]

I'm guessing a bad tire also. I've had that happen a couple times.

[markeb01]

I imagine every member here has at least one of these stories. Glad you got it figured out before something worse happened.