I am looking at buying a 2001 Yukon XL 2500 SLT w/autoride and the current owner says the 4x4 is not currently working because when his rear shocks were bad, he did not have the money to replace with the correct autoride shocks at the time so with the rear shocks being disconnected from the autoride system, the 4wd is not working, he states that replacing the shocks with the correct autoride shocks and then the 4wd will be fine, he says his mechanic told him this, anyone ever heard such a thing?? It does not make any sense to me...