Changing A Lawn Tractor Spindle and Pulley

Mower-Spindle - IMG_2108.jpg

Changing your lawn tractor spindle is fairly easy. It’s definitely within the reach of the average person. A basic knowledge of hand tools will take you through changing a lawn tractor spindle in a relatively short time.

My adventure started when I went a bit to far into a ditch with the cutting blades engaged. I managed to get the mower stuck. It had hung up on the mowing deck at the edge of the ditch. It was dug in so tight that I ended up having to pull it out with my truck. I tried to resume mowing. The result was an ear piercing screech of metal on metal. Of course, being stubborn, I engaged the blades again with the same result. A quick look showed that the splines on the spindle as well as the teeth on the pulley were worn completely out.

The Tools

The basic tools for this task are a set of wrenches, a socket wrench (22mm and 10mm), and a hex drive. In my case I used a 22mm socket and wrench for the nut that holds the drive pulley on. I also used a ratcheting drive for the T30 Torx bit as well as a 16mm wrench for the lawn mower blade. The Spindle cover required a 10mm Socket drive to remove the bolts.

Removing the Lawn Tractor Spindle

First, I used the T30 Torx bit and ratcheting handle to remove the cover that shield the spindle and pulley assembly. I foolowed these steps in this order to help with removing the Spindle nut. The nut has a nylon lack within it and can be a bear to remove. By removing it first, you can grasp the blade (preferably with a glove) to hold the spindle steady and drive the nut off. You can then remove the pulley, I left the belt in place when removing the pulley. Make sure to recover the spacer washer right underneath the pulley.

Removing Lawn Tractor Spindle Cover
Removing the Spindle Cover

One you have the spindle nut off you can remove the four bolts holding the spindle on. If you want to salvage these bolts, spray some penetrating fluid on them first and let them soak for a bit. The replacement spindle I bought already had new bolts so  I went ahead and bullied the old ones out, of course, two of them broke. This was fine since the spindle mounts from the bottom of the cutting deck. The four bolts go in from the top, securing the spindle to the bottom of the deck. Make sure to place the belt guide to the side.

Mower Spindle with Blade attached
Old Spindle with Blade Still Attached
Mower Spindle With bad teeth
Old Spindle with Worn our Teeth

Installing the Lawn Tractor Spindle and Pulley

Partially Installed Mower Spindle
Partially Installed Mower Spindle

Notice that I left the blade on to this point. More so to aid in removing the spindle nut. At this point I removed the blade. I set the new spindle in from the bottom and attached it with four bolts. Attach the two bolts closes to the frame (towards the inside) and finger tighten them. Then install the belt guide and finger tighten the two outside bolts. Once all four bolts are snug, use your ratchet wrench to tighten them snugly.

At this point I installed the blade. I wanted the blade in first so I could use it to hold the spindle in place while I install the spindle nut. After installing the blade, make sure the spacer washer is in place on the spindle. Place the pulley onto the spindle. Make sure the belt is in the pulley when installing it. This will make it easier to keep the belt inside the belt guide. Finger start the Spindle nut.

Mower-Spindle - IMG_2108.jpg
New Spindle and Pulley


I then used the blade I had installed to hold the spindle steady. Using the 22mm wrench on the nut, I tightened the nut down to what felt right (I did not find any torque specs on this). Once I had it down tight I re-installed the spindle and pulley cover. I also applied some Nickle anti-sieze to the bolts that held this cover on. Removing them was difficult, they were pretty corroded and resisted being removed. I want to make sure that I can get them in and out the next time I had to service the mower deck.


Here’s a quick overview of the steps I took to change out the Lawn Tractor Spindle:

  • Remove the spindle cover
  • Remove the Spindle nut on top that holds the pulley on.
    • Using gloves, hold the blade with one hand and remove the nut with a wrench.
  • Lift the Pulley up and over the spindle, set to one side.
  • Remove the four bolts hilding the spindle on to the mowing deck
  • drop the spindle and remove the blade

Reinstalling is as simple as carrying out theabove steps in reverse. There is one exception to that. Re-install the spindle first and then install the blade on to the spindle. This way you’ll have the blade to hold onto with a gloved hand when you tightent the spindle bolt on top.