Dryer makes a thumping noise when running

My fridgeidaire front loading dryer is making this thumping noise while its rinning and there is nothing in it to justify this noise any guidence would be graciosly accepted thank

Hard to say without being there to listen to it.

Usually on these models the rear bearing goes bad, but that would not make a thumping sound. I think the likely problem is with the idler pulley, but take out the drum and check it, the belt, the rear bearing and the other parts where the drum sits.

Here is the service manual which will show you how.

http://frigidaireservicetips.com/pdfs/363_5.75cuftGasElectricDryerGoodandBetterModels.pdf

You may also want to check the paddle in the drum, perhaps one side has come loose.