72 Blazer got the shakes bad - HELP

[Firebirdjones]

Originally Posted by Scrat

Worn spring bushings?

If they are original, I'd replace them anyway. 40 year old rubber bushings do strange things even if they appear in okay shape.

Since these trucks rely so much on the bushings (front springs especially) to run true, any play in those front bushings can cause a pull, vibration, sloppy feeling, etc....

That's the first thing I did is replace all the spring bushings with Poly. New rubber would be better than nothing, but I use poly to eliminate as much movement as possible. Any movement is transferred through the truck and the steering wheel, and how the truck reacts to steering movements.

[cleszkie]

Regarding balancing of tires,thought I'd also like to the list of things that could be done wrong by the tire balacing place based on my experiences:

1) Some rims are lug-centric, and some are hub centric. I believe the stock steel rims on out trucks are lug-centric (centered about the lugs not the hub). However, most tire balancing places have machines that balance tires by securing the rim by the hub openning, thus balancing a lug-centric rim by assuming that the hub center is the same as the lug center, which it isn't in most cases. This results in a poor balancing job when the rim is put back on the lug-centric mounts of the truck. This is a little know fact (maybe not on this board), and others will chime in if I'm making any sense here. Find a shop with a lug-centric balancer, and you will get much better results.

2) Some of the tire balancing monkeys try to load all of the weights on the inside or outside of the rim. Yes, it looks better if there are no weights on the outside, but you will be sacrificing the effectiveness of the balancing job. If you want a good balance, you may need weights on the inside, outside, and even some stuck on the backside inner dish of the rim between the inner and outter lips.

[Firebirdjones]

I do Static balance wheels (weight inside only) if the rim doesn't have a beauty ring to hide the weights, or if the wheel is aluminum.

Simply because it's clean looking, plus a painted steel wheel, come balance time again, those outside weights will be moved, which leaves chunks of paint missing. Can't have that on a show piece.
Technically wheels should be balanced much more frequently than people do. I balance every second rotation. Those painted wheels would start to look pretty ugly on the outside pulling those weights off all the time Not to mention I hate to mar up an expensive aluminum wheel.

As long as the wheel is straight, and it's a well made tire, along with a good balance machine, you shouldn't have any trouble static balancing. I've done it for years without an issue.

[low'n slow]

Didn't see anyone mention motor or tranny mounts.

[Ole Beater]

Make sure your front hubs are unlocking and that your front axles arent turning.

[Ole Beater]

Oh wait you said that you feel it in the sea of your pants. Thats definitely somewhere in the rear driveshaft back.

[pumpkin]

Seized u Joint ? Especially the front, can cause a mean vibration. Pull the drive shaft and make sure the joints move freely with no binding.

[Steve-W]

has the truck ever been in a major accident that the frame is distorted? the wheels might be aglined, but stil could cause problems.