Alignment facts

Out of round tires causes bounce. It's also very difficult to keep the fat tires in good balance. It works out better to stay on top of keeping them in balance and keep good shocks on the front end than prematurely replacing a tire due to lack of preventative maintenance. Once the tire becomes out of round and or extremely out of balance you can only live with it or replace the tire.

As for as inside tire wear goes on dump trucks with heavy axles and fat tires, alignment should be very close to zeros for camber and toe. Wide tires need to set flat and the big axles don't flex so no need to build much positive camber into them. With your inside wear issue, you could be slightly toed out causing this or slightly negative on your camber, but if you have an 18 or 20,000 lb axle you won't be able to bend it to change camber, so set your toe at very near zero, it's all you can do.

 

Vibrations at 30 or 62 mph are specific issues. 30 mph is typical of a belt failure in the tire. 62 mph is a balance issue.

If a vibration follows road speed, suspect a u-joint or something other than a tire, typically.

Shocks will show up bad as tire bounce on rough roads and signs are cupping also.

 

even when i replace the tires new it has a bounce in it....i even had a shop try to bal. a set of them once they put on the sticky weight like they would stay on this tires..lol but the bounce is still there..king pins where replaced a few yrs ago, and have no play in the tire when lifted in the air...may try some new shocks...got a new set of toyo tire for the front now that i am waiting to go on...had a front rim crack last year and going back with the alum. wheels this time....steel on it now but had the same bounce with the alum. before it cracked...also the bounce is jsut there at about 30 to 35/40 then its gone..thanks mike

 

spin balance it on the vehicle.

You may also have a drum that's out of balance too.

There's a lot of unsprung weight hanging out there to manage. Shocks should be replaced bi-annually. not "whenever".

Check with the manufacturer on the actual service life. You'll be surprised what it really is.

 

Many tires don't center on the rim properly when installed due mostly to lack of lubricant to seat the bead and some of the quick installation procedures being used. I've seen many that spun up like an egg, had them remounted with lots of lube on the bead, then spun round. This could possibly be the cause of the bounce.

 

ok thanks guys

 

I agree with MN. That was the first thing I thought when I first read post #1. Caster is the vertical axis the wheels turn from left to right. Big trucks might be a little different as the OP stated perpendicular. But many four wheelers are set at a positive angle.

Every big truck alignment I had, they just adjust the drives so it tracks properly. Caster and camber are always within specs. You have to hit something really hard to mess the front up. All it takes is one good pothole or dip loaded and you can bust a shock. That is what I would think is the #1 reason along with tire pressure why front tires prematurely wear out. Factory shocks are cheap.

I know it's a 4 wheeler. All I could find easily. Some stuff I borrowed from AlldataDIY to give someone that never fooled with it a general idea.

 

I bet it's the shocks. The first thing the tires will do is start to develop a chop on the treads. It gets more obvious as they wear more.

Where did the aluminum rim crack at?

 

it cracked in the part of the wheel right above the lip as it turns up to be flat hope that make sense..just a hair line crack no damage or anything..i think it came from all the lube that is used to install the tires...cause when i took it off and checked it from the inside it was just pitted really bad ..now i have 3 good rims and 1 big door stop lol...got 2 more used wheels for a great price 200.00 just like what was on my truck...so said i could fix the wheel but ,i will pass had a buddy go down a ditch bank at 60 with 20tons of stone on his back rolled a few time lucky he didnt get hurt ..front tire blow from something in the road.....i will price me some new shocks ,i just replaced all 4 on the back the end of last year cause of a rough ride...(hend rubber block ) mike

 

Check for any rim to hub off center. Even though hubs have those locating tabs to center the rim, it is becoming more common to see a gap between one of the tabs and the rim. The rim doesn't mount centered to the hub and will spin out of round. To check for this you would jack up the axle and spin up the wheel and watch the top of the tire to see if it is moving up and down as it is spinning. Same test as what Bender was saying about mis-mount between tire and rim.