Bouncy Bouncy Ride

[Woodenhead]

Shortly after I bought the truck last year I noticed a bit of a hop/bounce at slow speeds. At about 20mph it seems to be just at the right frequencey that I'm slowly bouncing up and down in the seat. Any faster than that and it speeds up to the point where it goes away. When driving slow you can actually notice the front end bobbing a bit, it's getting kind of annoying in traffic. At first I figured it was a toasted rim or tire but after putting new rims and tires on (needed em anyway) it did the same thing. All U joints are good, front ends got new bearings and races and it doesn't shake at high speeds. I'm at a loss for this one, I think I may put it up on stands and run a dial indicator on the ID of each rim to start checking if something may be off centre. Any thoughts as to what could be causing this are appreciated.



Thanks

Mike

 

[Matt S]

Mine does the same thing but only intermitantly. I have yet to figure it out but it only happens at slow speeds.

 

[Woodenhead]

Just realised tonight that it's something in the back end thats making the truck bounce. Tonight I was on some nice slick ice with the back tires turning slowly (not moving ahead) and still bobbing up and down. The previouse owner had put one (yes only one) new drum on, I guess it's possible that it was m/c'd slightly off centre so the wheel and bearings aren't centered. I would think if this were the case it would shake at higher speeds.



Mike

 

[Boldt's Wagon]

Seen this on a car 40 years ago that had been in an accident. It was a bent rear axle.