after you complete the inspection mentioned above, roll the belts off the spindles. Spin each blade and listen for dry / failed bearings. Examine the sides of the sheetmetal pulleys that may have bent. This may pinch the v belt causing a thumping sound. Look for chunks of missing rubber on the v belt. a slightly bent blade may be hitting grass build up.

Removing the deck would allow a better inspection.

Yep. Gonna start raining again, so I'll pull the deck and get serious. I have another and newer 26HP GT Hydro which does a much smoother cut. I use the old beast for the first cut in the spring for finding rocks and other winter debris which lurks in the grass. Didn't have much of a winter but a couple rocks still came up-which I saw and didn't hit.

Thanks guys,

Raining like time to build an ark. Anyway, took off deck, all covers and checked everything. No noise on any mandrel's, idlers, belts are good, guides in place and properly adjusted. Except for the idler on the tension arm for the belt that is driven by the tractor engine. Everything else when "spun" kept spinning, this idler only turned when force applied. Looking up part number, Sears wants $39.95 + S&H, Evil Bay on the other hand was $15.99 delivered. An outfit I've dealt with before so on order supposed to be here friday. Just realized that this is the first $$ I've spent on this deck in 18 years, other than belts. Not bad.

Thanks again,

You know, I use Sears Parts Direct many times for look up. One time you look at a 6$ belt guide and they want 40. The next time a 20$ cable is 12....

Yep. We'll miss Sears when they're gone, 'course, they've been going for years now...