tire problems

ok guys 1997 freightliner fld112 dump truck started a bounce a while back and the other day I was looking around to try and find out the problem....I was thinking I had some rims that may have slipped around or something.. but anyway I looked at my tires and was shocked at how they look....the tire on the pass. side of the truck front tandam inside has a spot that is about flat and about a foot long, and the tire on the driverside inside back tandam is the same way so it has 2 flat spots 1 on each tire... but what makes this happen I just put the tire on about 6/8 mths ago new and I gotta to think this is the bounce that I feel...

this is the inside pass. side front tandam you can see the diff. in the 2 tires put on at the same time..




this is the inside driver side back tandam tire put on new at the same time....

thanks for any help

 

yes tire wear on the inside on both sides.. shocks are new a few mths old front and back.......

 

Same tire and tread on the top pic. Put on the same time..that's what I don't get..the bottom pics same tire put on the same time ..

 

Yea I'm thinking the tq rod bushing that run from side to axle and rear to mount.. will be looking at them today...

 

Tires are all 11/22.5 all the same size..new caps