Confused About Vibration

[bulldogrider]

seams to be a common problem with macks of this era.

Tires, driveshaft,U joint,Cab rubbers,Motormounts, shocks, springs are all possible things, Start with the easy stuff first.... Its never one issue. My truck had the same problem. it was bad shocks and tires

i'm a new member here and a long time 1993 ch613 mack owner,i'm glad to find this website so i can share and learn. i have exactly the same problem shacking starts at 60km speed and goes away at 70km, i replaced all the drive tires and the steering as well, had the drive line checked and was all messed up its all good now,the motormount front one was loose been replaced rear ones are ok, the chaking gone now but i still have vibration on the steering wheel, and now starts at 60km speed and stays no matter how fast i go, but definately the drive line is 100% ok cause i can feel nothing in the butt its all on the steering wheel,could it be a tie rod end? or a drag link? any suggestion would be greatly appreciated.

thanks.

note: the brake pads on the steering been replaced few months ago. mechanic told there was gap on kingpin driver side he put a chime there.

Edited December 18, 2010 by bulldogrider

[Underdog]

Check that the brake drums and wheels are centered on the hubs. I had this issue a while back after I replaced steer axle brake drums. On a truck this old, the tabs for the hub pilots may be worn to where they don't hold the drum & wheel centered oon the hub. There are two options if this be the case. New hubs, or do what I did... install TRU-BALANCE centering sleeves. This product does what the seller claims! Look online or in the trade magazines; I would recommend TRU-BALANCE to anyone with hub pilot wheels.

Gregg

[bulldogrider]

thanks Gregg for your reply i been waiting patiently for a reply from someone, your suggestion makes sence as i said i have this truck for 8 years now and probably the hubs are worn out, i checked this website out:

http://www.tru-bal.com/index.cfm/fuseaction/category.display/category_id/238/Internal_Centering_Sleeves.cfm

and i posted it in case someone might use it, anyway i'll talk to my tire shop tomorrow and see if they have this prodect in stock if not i'll see what he has to say, although he re-balanced the steering tires twice already. i'll le you know.

thanks again.

Edited December 21, 2010 by bulldogrider

[Underdog]

Thanks. I would have linked to their site myself if I knew how! Definitely money well spent on this product. The steer axle balancers are easy, you install them once and they take care of the wheel and drum. I also bought the sleeve tool for drive and trailers, but I have run across some tire shops that don't want to fuss with them because it takes an extra 3 MINUTES to install wheels. Usually those same establishments don't own a torque wrench either!!! This is why I do most of my own tire work so not much of an issue for me.

Gregg

P.S. Make sure when replacing brake drums that the stud hole I.D. on the new drum is the same as your old. I found out not all "universal" drums are the same. I had to shop around a bit to find one that fit with my TRU-BALANCE sleeves.