Truck shaking vigorously! Help!

JesseRafael · September 25, 2015

Hello, I have a 2005 GMC Sierra 1500 5.3L 2WD. I recently experience my truck shaking when I'm on a local highway. My transmission is hurt, my 2nd gear is slipping. My 1st gear works fine. So I have to speed off and once I'm past 2nd, around 20-24, I ease on the gas, then go into 3rd gear just fine and everything else works good too. I don't drive unless I really have to. Don't worry, I decided to go with a rebuild within the next month. This my have something to do with it. As I was saying, when I am on the highway, the truck just shakes up and down real bad. The bed just shakes up and down and it is really embarrassing. The front does shake as well, but less than the rear end. I knew why it was shaking at fist, or so I thought. I have a 3in lift kit on my truck. The driver side rear shock was totally shot. It would stay in the compressed position, while the passenger rear shock was fully functional. I replaced both rear shocks with used rear shocks,to save a little money, roughly the same length extended as the ones I did have. Maybe 2" shorter. When I got on the the local highway, my shaking problem was temporarily solved. Could this be of the tranny? I was thinking it could be the struts? One of the rear shocks was shot, so maybe the struts are out as well? The pics below are of the old shocks, also could anyone help in identifying the manufacturer of these shocks? Sorry for it being too long. Tips/advice would great. Personal experiences would be a plus. All responses are greatly appreciated!

nadrojcote · September 25, 2015

A shaking up and down could be due to roadforce, also known as hard spots or flat spots on your tires.

JesseRafael · September 25, 2015

A shaking up and down could be due to roadforce, also known as hard spots or flat spots on your tires.

@projectsummit Thank you for your quick response! I forgot to mention, I'm running 305/35R24 tires. Could it be because of unequal tire pressure? These tires do not have a lot of sidewall to begin with. I put 40 PSI in my tires.

nadrojcote · September 25, 2015

@projectsummit Thank you for your quick response! I forgot to mention, I'm running 305/35R24 tires. Could it be because of unequal tire pressure? These tires do not have a lot of sidewall to begin with. I put 40 PSI in my tires.

Very easy to bend those big rims, check the rim lips to see if theres any visible dents or flat spots. I hit a curb going very slow with my 305/45r22's and put a dent in my rim recently and I have excessive road force now. I had the tires roadforce balanced and they found a flat spot on the lip of my rim.

JesseRafael · September 25, 2015

Very easy to bend those big rims, check the rim lips to see if theres any visible dents or flat spots. I hit a curb going very slow with my 305/45r22's and put a dent in my rim recently and I have excessive road force now. I had the tires roadforce balanced and they found a flat spot on the lip of my rim.

Oh damn, I haven't heard of roadforce until today. I will definitely ask my local shop about this. Thanks for the advice. Will definitely look further into roadforce. Appreciate your time.

barry G · September 27, 2015

stuck shock on one side..

means two different spring lengths.

one tire will be forward of the other.

are the hubs discolored?

it is rather funny, you gained something a 4x4 would get.

JesseRafael · September 27, 2015

stuck shock on one side..

means two different spring lengths.

one tire will be forward of the other.

are the hubs discolored?

it is rather funny, you gained something a 4x4 would get.

The rear shocks I replaced were both exactly the same, just the driver side rear was done for. What do you mean by one tire will be foward of the other? Again, what do you mean by hubs discolored? Thank you.