Bouncing in rear after new tires & 3" RC suspension lift

[mwardncsu]

I posted this over in the Lifted sub-forum, but it may be better here...

just finally finished the install of a RC 3” suspension Level/lift (new springs / shocks on front, new shocks and block on rear) on a 2004 RAM 1500 single cab, 6.5’ bed with RWD.
Had Cooper Discoverer XLT 285/75R17 tires installed (previous were 265/70R17) on existing wheels and a alignment performed.

The truck is pulling to left a fair bit so I’ll need them to relook at the alignment - but even worse at 45 mpg there is a pronounced and sustained "bounce" which I believe is coming from the rear. Below 45 it seems ok and once I get over 50 mph it settles out again (haven’t gotten it above 55 yet to see if it occurs again at higher speeds).

I’ve seen some reference that perhaps the tires may be a little over inflated, or others have described something similar at 45 mph and said new shocks solved it - but I’ve got new shocks via the kit

Anyone experience anything like this and have suggestions?

 

[Nick@GotExhaust]

i would start at tire pressure. easiest thing to check and solve. It does sound like too much tire pressure. Were the tires installed at a dealer shop? They are notorious for over inflating tires for some reason

 

[mwardncsu]

yep - installed (and the alignment performed) at a tire place. First thing I'll check tonight when I get back home.....

 

[mwardncsu]

so the sticker on the door says to inflate to 35 psi cold, and the tires were at 45-ish. I dropped them all down to right at 35-37 and the bounce seemed to be gone sat 45 at least for the first 10 minutes or so - then it came back - though maybe not as bad as yesterday. I meant to check the pressure when I stopped (was taking it back to the tire place for them to check the alignment tomorrow) - to see if the pressure had increased as the tires warmed on the road.... may just need to drop it down a bit more - but wondering if there is another issue going on.... going to try and get them to re-check the tire balance as well