SP Daylight 4449 4-8-4 GS 4 with DCC sound

[JEL1948]

I just purchased a lightly-used 4-8-4 SP Daylight. I've run it around my 22" curves and it negotiates them OK. However I notice that the front and rear trucks (front and rear of the big drivers) are extremely loose and wander a bit side to side...is this normal? Should there be a 'keeper spring' to keep them steady and in firm contact with the rails?