Trunnion Shaft Moving

[grumpydumper]

my 84 mack dumps trunnion shaft is moving side to side about 1/2 to 3/4 it has bronze

bushing

[Rob]

my 84 mack dumps trunnion shaft is moving side to side about 1/2 to 3/4 it has bronze

bushing

Sounds like it is time to rebush, and realign the locator arm stops on the stand or cross tube if Camelback suspension.

Rob

[grumpydumper]

thanks rob how much side to side movement would you say was to much?? the bronze bushing look good from the end it just

seams that it needs thrust washers or somthing

[Rob]

thanks rob how much side to side movement would you say was to much?? the bronze bushing look good from the end it just

seams that it needs thrust washers or somthing

I've never realigned one myself but have looked at both new trucks, and ones that are worn out. If you look at your crossbar there will two weldments to the tube itself. These weldments rub or mount against the arms that are the trunion stand. I would say zero clearance is what is acceptable with a +/- factor of about .100 which really is not much. It is normal for some walk of the axles to the side during a turn due to the forces of the arc not being equal. I've read someplace that you either cut the weldments free and reposition to weld, or weld up and dress them, or the stand for the same purpose.

I don't think it is that hard of a job but like everything else on trucks, heavy. adequate jacking equipment and stands are a necessity.

Rob