Re: Can?t diagnose shaking problem
we had this kind of problem with a truck once, turned out the clutch pilot bearing had begun to come apart...and not keeping the input shaft centered anymore. causing vibrations that became MUCH more obvious when loaded.
i also saw a u joint that had disintegrated the roller bearings in 1 cap. light throttle low loads and you felt almost nothing, load it hard and it would shake till you slow down, never towed while the truck was doing that as it was winter time.
both these situations sent the vibration from one end to the other and back again rythmically, and a lot of time was spent chasing them,
the clutch eventually got bad enough it would shift properly, and the u joint was found by deeming all the steering components good, having new tires on it, etc we decided it was either the rear gear or the driveshaft, so we started cheap with u joints and found it.
edit, one other potential cause is a twisted driveshaft you likely wont see it with the naked eye asit doesnt take much
, i chased this in a hot street car, the factory driveshaft was basically too small diameter, and would deflect and twist under load and cause the same reverberating shakes...it also caused reverberating noise to echo through the car... went to a larger diameter shaft and the problem went away. again, if i kept my foot very light and never allowed it to get started shaking it wasnt nearly as noticable...get it shaking and the only way to stop it was slow way down...
