I just put tubes in the rear tires on my John Deer L110... they won't engage What did I do wrong putting them on?

Where can I find an owners manual for a 17 1/2 hp yard machine riding mower. I really need a scematic for the rear end gear box. I took it apart and forgot how to assemble a spring on the right side of mower. I was trying to find out why the mower is lunging when it is in gear. I replaced the trans belts and then thought a gear may have been broken. I found no gear issues but it is still lunging, especially when the pto is engaged. Can you help me. /it feels like a belt is loose but they are all tight

We got two different posts going on here and ivt465 was here first. Love2 you must go to the top of the page and click ASK so you can start your own post. I am answering ivt's question only here. Installing tubes in the tire will not cause this problem. However if your wheels had keys on the axle and you left them out you could get this issue. Did they have a keyway and key? Check the drive belt to the tansmission from the engine, does it move when you put the unit in gear?

Did you put the shear keys back on the axels there square shape a couple inches long