Front end shakes and bouncing??

If you have a name brand, quality tire installed properly, you should never need balancing. The biggest problem with tire installs is that they do not get properly centered on the rim. To check this you need to jack up the wheel and spin it. If the tire is mis mounted you will see the tire going up and down as it is spinning. Balancing will not fix this. It has to be remounted.

 

Sounds like the tires weren't mounted centered on the hubs.

 

I had same prob on my w9 replaced frt spring shackle bushings. Some kws used screw in ones. Do you notice more shaking on heavy crowned road or in certain side winds. It can unload frt springs enough at times my would start shaking bad. I would get hardly any shaking going to Cali but coming back with wind out of nw would rattle my fillings local wrenches thought I was nuts until they drove it in crosswinds. Lol Jack up frt take 2x4 place next to tire and give it a spin c if any side or out of round.

 

all so when you jack it up if the tire start spinning they are not balanced form what a tire shop told me

 

How much did it cost to get rebushed? Any body else got rebushed, looking for an idea of what is a good price to get my freightliner rebushed.

 

With steer tires I start with jacking up the axle and pick all the stones out of the treads, (this is just for safety). We have a tire spinning machine that I will butt up to the tire and spin it up to highway speeds. (this is why you pick out the stones, LOL) Anyway, if the tire and/or rim is out of round you can see the tire bouncing as it is spinning. I have a tire crayon that I will hold very close to the tread of tire just to the point where the tire makes contact. Only the high spot of the tire will be marked by the crayon. Stop the wheel. Move the wheel so the crayon marks are at the top. Loosen the wheel nuts, give the wheel a bit of a shake, then retighten the wheel nuts. Spin it again and see how it is. Most of the time, after a try or two, the tire is near perfect and problem solved. Sometimes the tire is mis mounted. I will do the same thing, but not spin it as fast and watch the edge of the rim where it meets the tire. Most tires have a bead line in the rubber very close to the rim. As the tire is spinning you can watch the edge of the rim and bead line and see if the gap between the two is drastically changing. This indicates a mis mounted tire. You have to remount the tire. 80% of the time all I have to do is deflate the tire, relube the bead area on the tire and rim, hold the rim still but spin the tire 180 degrees and inflate the tire. If the tire is well lubed with tire mounting compound it will nicely center itself. Most guys do not put enough lube on, or use those cheater air cannons which cause mis mounts. Also, most tire mounting compounds do required mixing it with some proportion of water to get the correct mix. Most guys don't do this either. Once you have a happy tire and wheel, everything else is smooth sailing!!!

 

Rule of thumb. below 45 mph - out of round, 45 to 55mph toe, over 55mph balance( drum and hubs included). The faster the truck rolls the more toe-out force is exerted on the steer tires. If there are worn components on the steer axle, such as a small amount of wear in the tie rod ends, loose wheel bearings or king pins, the set toe can easily change well over an 1/8". Remember when we were kids and you would hold a bicycle wheel by the axle and spin the wheel, there was a force moving it side to side. This same force exists in steer tires and will work against each other with a small amount of toe-out. I have found this is an issue often over looked by alignment techs. I check tie rod ends with a large pair of channel lock pliers, for any vertical movement( should not be over 1/16"). There is not one set toe for all vehicles. Long haul truck 1/16", with a small amount of wear in steer components, 3/32". P&D and dump trucks, as much as 1/8". Caster should also be checked, excessive will cause a wobble. Another over looked item are the shocks. The purpose of a shock is to keep the tires on the ground. The easiest way to check is to buy a temp gun and after coming off a long stretch of hi-way, check the lower portion of the shock tube. They will be warm to hot and should be the same temp side to side. This is also a great tool for checking wheel bearings and tire pressure. A tire that's hotter than the rest will probably be low air pressure. Hope this helps. Edit Post Reply Reply With Quote