MOWER CONTINUES TO PULL AFTER DRIVE CONTROL IS RELEASED

Remove rear baffle to gain access to the transmission. Likely the area has become impacted with debris preventing the transmission from releasing drive belt tension.

See instructions for drive belt removal, pg 18 of the owners manual. Free download of the manual at Husqvarna, see following URL.

https://www-static-nw.husqvarna.com/hbd/tdrdownload/pub000050055/doc000089703/-1507920334?httproute=True

Hi Diana-
I found this youtube video on replacing the belt and removing the deck on a Husqvarna riding mower.
https://www.husqvarna.com/ca-en/support/manuals-downloads/

I also found this link for your Husqvarna R120S owners manual (OM) which shows you how the drive belt is suppose to be placed on the mower deck.
https://www.husqvarna.com/ca-en/support/manuals-downloads/

Hope this helps.

Start by removing the belt keeper around the back of the engine pulley, unhook the deck drive belt and pull out of the way, now remove the spring on the idler pulley against the drive belt, there should be enough slack now to hook the belt over the fan one blade at a time until free, now push it forward and feed off the engine pulley and feed down and out, it is a fairly tight fit, refit the new belt in reverse.

Hi Willard, The link below is a web page with the diagram for your lawn mower.......CHEERS..
Diagram of drive belt for husqvarna rz4623 Google Search

belt wrong size make sure the tension pulley is there to take up slack cable needs adjusted

there is a rod that hangs out above the hitch you pull it out and move it into a released position when done release and push it in

The drive belt is the topmost belt, next to the frame of the tractor. So jack up the front end, lower the deck and take a look at the engine shaft if there is a loose/broken belt laying up there. If so then you are right. You will have to remove the deck to replace the belt. There is a spring loaded tensioner, released by the brake pedal, so you will need a confederate to hold the pedal down for the last step of install. Begin by putting the belt around the big pulley on top of the transmission first, then the engine pulley. If the belt is in place then you most likely have a fried transmission and they are so expensive prepare to get another mower.

check the drive belt. Deck belt has nothing to do with tractor motion.

You can try putting a little more tension on the drive belt. It is probably stretched out a bit and the drive engagement cant cancel all the slack out. So, the belt slips.

Pull out your owners manual and look up instructions for tightening the drive belt. If you dont have a manual go to the Husqvarna website and get a PDF copy.

Good luck and be careful!

This seems to be the correct part no. for the 36" deck, is the belt definitley the correct one, it should have the no. 174978 marked on it.