Sway on back

Hi probably been asked before what makes the back of a freelander 1 (van 3 door 17" alloy rims) sway. Not dangerous at moment but I am moved side to side depends on road surface. Do have different manufacturers tyres fitted on rear. Could it be this or a buckled rim. Have checked wheel nuts but friend of mine that was following me said it looked like one tyre on rear was running out of true. Taking to tyre specialist for rim and tyre check. Just wanted to know if anything else needs changing or checking.
Thanks
Dave

Normally the freelander is very stable on the road. I does need matching tyres all round though, or serious transmission damage will be done.

Nodge68 said:

Normally the freelander is very stable on the road. I does need matching tyres all round though, or serious transmission damage will be done.

Click to expand...

Nodge68 said:

Normally the freelander is very stable on the road. I does need matching tyres all round though, or serious transmission damage will be done.

Click to expand...

Well it was now rims or tyres. Had a lightbulb moment. Used hand to gauge tyre to wheel arch gap. Low and behold rear spring on drivers side is giving a shorter gap. Working on fact that springs and shocks will be replaced. Any recommendations for manufacturer or spec.
Thanks
David

Check for broken spring or rotted spring base on shock. Spring determines height, shock simply damps bounce.