Husqvarna YTH180 runs but won't go into gear

bad reverse check valve take it in about 100.00

generally signs of a failing transmission. yes you can replace it yourself in less than a day with the proper tools. get the whole thing up on jacks, drop the deck, remove the wheels, remove linkage and belt, remove bolts and the thing falls into your hands. problem is that you can buy a used mower for less than the price of a transmission. look around for a used or possibly rebuilt exchange transmission. google helps a lot.

there are mower boneyards around, you just have to look. try a google search in your state. also try ebay and craigslist. my yth 2148 looks just like my neighbor's craftsman, but the decks will not interchange.

Obviously you haven't looked very hard for it yet.
A simple Google search for "Husqvarna yth 180 manual" returns thousands of sites, the very first of which has 10 or 15 different PDF downloads for manuals for this tractor:

lawnandgarden.manualsonline.com/manuals/mfg/husqvarna/yth180.html

whats rough the motor if so you could have bad gas or bad plugs or somethin els you may need to get that to a shop

Make sure that the tranny has fluid in it. Then try rocking the mower back and forth until you rock the tranny loose.
Best regards, --W/D--

Hi..my name is Keith...and i havent worked on that lawn mower model..so i cant tell you exactly where the safety switch is..but it sounds like the reverse safety switch has failed and the lawn mower thinks you are in reverse..so i would look around your foward-neutral-reverse shifter for it...i hope this has helped..if not write me back

sorry. I don't have an ansewer for you however I might have some helpful hints. Your mower should be going dam near 5 MPH. But yes can't cut in reverse. you have a belt going from the trans axle to the motor. It could be slapping against the frame. The idler puller or the tension pulley could be wobaly where the bearings are gone out. If you remove the 4 bolts on the back of the mower under the seat and gas tank it should visable tell you the story. My question is mine hits gears real hard as if trans mission needs oil or internal damage.

sounds like you need a new drive belt