pflan

Yeeeah I also thought about possible bad shocks.

I don't know.. to describe it better, it's more of a bouncing feeling at 35-45 MPH and more of a shaking at interstate speeds.

bubbabowman

Yes mine are and felt no difference

tansupercrew

I feel like you answered your own question, you said the spare is on the front with a new m/t and worn out m/t s on the rest. Try a balance and maybe even rotating that one new to the back. What size tires are they? Also do the rims have a lip in the outside to put weights on? If not they may be "static" balanced where only half the tire is balanced. If you are unclear, just insist the place that balances them does a "dynamic" balance. If you have much larger than 33s, you may even be able to use counteract- which are self balancing beads you put in the tires that truckers use.

pflan

Well the spare has a new A/T, not M/T.. which probably makes even worse. But the tires are just 245/75/16. I have some new Unique 297s on order and am just gunna find some decent used A/T's. So maybe that will help the rough ride.

But what scares me is that at very slow speeds, when hitting even the smallest bump in the road, the rear end makes it feel like I just ran over a dang boulder or something.

I'm obviously no mechanic, so any suggestions help.

Thanks guys

FL_F150

Yeah, the 35-45 shimmy/vibration means you need to get your wheels balanced, but i'd gett'm all four (or at least two and two) rubbers to match.

The small bump problem i'd look closer at, jack up the read and get in there and shake the heck outta anything you can, springs, axle, axle U bolts, or anything attached to the rear end. Sounds like something is loose back there, i'd jack the frame so that the axle is free floating allowing for movement of things that might be loose.'

tansupercrew

Do you have any rust on the bed? You may have some rotted out bed mounts. It's pretty common, in PA anyways.

Cdn Paratrooper

I have found these trucks to be very tire sensitive, if your tires are out of balance, low or high on tire pressure or of a certain manufacturer, the truck rides and drives differently.

As for the slight bounce, seeing as you have just bought the truck, the previous owner might have put that tire puncture sealer in there and not settled it correctly...?

My suggestion is if the tires are almost worn out-get some new ones..if they are still good-go get them checked for balance and broken cords (bulging of the sidewalls can indicate this).

pflan

Thanks fellas. Yeeeah, rust isn't really a huge problem here in Georgia, but I'll check that. So it seems that most of my "rough ride" issues come from the wheel/tires being unbalanced and different. My Unique 297 wheels should be ready for pickup on Monday and then I'll go get some matching rubber for 'em.

Other than that, I'll shake the rear end parts and see if I find anything loose and go from there.

Thanks again guys.