caster or cheap front tires

[macattack]

just wanting to know if any other mr688s owners know if they have one or two spring wedges. one per front side?

mine only has one and i am thinking the original owner had some spring work done on the pass side and didnt replace the wedge on that side. should the wedge be installed thick to back axle or to front bumper?

my question is if my caster was out of adjustment because of one wedge would this cause my truck to wobble from 40-45 and after 45 she rides nice. feels like a flat spot on my front tire. but there brand new and checked out fine. i have beads installed and that helped but not a 100%. dont know if it s the cheap made in china HERCULES 425 65r 22.5 fronts or the one wedge misssing.

also if i needed a caster adj would my steering wheel shake. because its smooth. happens when coasting also.

thanks

[redrider]

Get rid of those Hercules for starters. When I had my shaking issue, the tire shops told me that the tires are sometimes out of round, not necessarily out of balance. Goodyears are garbage. Go Michelin or maybe Bridgestone. You get what you pay for.

edit- tire shops only check the tire by jacking it up and spinning it, not when it's on the ground. Weight makes a big difference when you're trying to find a problem.

Edited May 21, 2013 by redrider

[39 Baby Mack]

I would think it should have one on either side and the fat part goes to the back.

Ron

[macattack]

thanks guys.

would an out of round tire smooth out after 45 mph? mine shakes the truck between 40-45 mph after 45 its fine. i would think an out of round tire would always be shaking??

or is my thinking wrong.

[thomastractorsvc]

The wedges are for the caster angle

symptoms of not enough caster are low speed wandering or weaving at high speed

symptoms of too much caster is hard steering and impact shimmy

symptoms of uneven caster will cause it to pull to one side

Caster does not show any tire wear.

[wastenafarmtrucking]

check your toe. give it 1/8" toe in and see what it does. I've heard many of a mack wobble/bounce being fixed by toe in.

[41chevy]

Did the problem exist before the tires were changed? Paul

[redrider]

thanks guys.

would an out of round tire smooth out after 45 mph? mine shakes the truck between 40-45 mph after 45 its fine. i would think an out of round tire would always be shaking??

or is my thinking wrong.

When I had my issue, the truck would sort of hop at about 5mph and then smooth out. Then right at 50mph(80kmh) it would shake violently, 85-90 kmh it would smooth out again and would be smooth anywhere after that...with Goodyears and Dunlops. Michelins are the only ones that work for me.

Negative caster angles would scrub the tire around corners and the steering would not return to centre on its own. Too much positive and the truck will want to keep pushing straight IIRC. To understand caster better, do a search on pirate4x4.com. Those off road guys know geometry the best. Lots of good info on there.

Edited May 21, 2013 by redrider

[macattack]

thanks for all the info gang. i actually never got to drive it with the old tires, but i know they were alot narrower tires on the front.

i am gonna swap out those hercules and have the toe in checked. see what gives.

thanks again gang.