A deck spindle is a shaft supported by bearings that transfers power from the pulley to the blade, rotating hundreds of times per second. After so many rotations, it’s inevitable that these parts will fail, requiring replacement. How do you know a spindle has gone bad, and what do you need to do to install a new one?
When Do I Need to Replace a Spindle?
Spindles fail because the bearings inside break down. As the metal in the bearings grinds down, the shaft is harder to turn and can move out of alignment, stressing the housing, pulley, deck and drive belt. There are three symptoms that indicate spindle failure:
– The spindle won’t spin freely. This can cause belt squeal, and will be noticeable if you try to turn the spindle by hand.
– The bearings make grinding or squealing noises.
– The resistance creates large amounts of heat around the spindle.
Premature failure is caused by a lack of grease. While this requires physical damage to cause failure in the sealed spindles found on most Cub Cadets, there are still some professional models that use grease fittings. Check your owner’s manual for instructions and guidelines for greasing your mower’s spindles.
Planning Your Repair
A little preparation and the right tools will make this job a lot easier.
The bolts that have held the spindle to the deck have been exposed to years of water and debris, which makes it highly likely that they have rusted in place. Penetrating oil is an absolute must. If possible, spray down the bolts and pulley the day before working on your mower to give the fluid time to loosen things up. A small impact wrench will also make it easier to remove these bolts, as the impact action helps break the rust loose without applying steady torque that can strip the bolt head.
Most Cub Cadet spindles come as a complete assembly, but a few models use a separate pulley or shaft. While it may seem frugal to reuse these parts, they should be inspected thoroughly: a pulley that has seen the same wear that has caused a spindle to fail may be all but impossible to remove, while a shaft of the same age is likely to be pitted.
Removing the Old Spindle
First, remove the deck from the mower. Instructions can be found in your mower’s owner’s manual.
If your deck has a center spindle, it will be exposed, while the spindles on the sides of the deck may have covers that need to be unbolted from the top of the deck to provide access. Once the pulleys have been uncovered, slide the drive belt off of the pulleys.
Most replacement spindles come with a pulley installed. If yours didn’t, now is a good time to remove the pulley from the old spindle. Use a wood block to keep the blade from spinning and unscrew the top nut on the spindle. Lift the pulley off of the spindle. Some penetrating fluid and some light tapping around the face of the pulley may be needed to shake it loose. If the pulley is tight enough to require a puller, it’s probably a good time to replace it.
Flip the deck over or lift it to a height that allows access to the bottom of the deck. Remove the blade, then unscrew the bolts holding the spindle to the base. The spindle can now be removed from the deck.
Installing the New Spindles
Clean the area around the mounting holes and spindle mount on the deck: more than likely, there will be a thick layer of compacted grass that can get stuck in the holes, preventing the spindle from mounting flush.
Turn the deck over, positioning the spindle underneath it. Screw in the bolts.
Follow the removal instructions in reverse, reinstalling the pulleys, belts, and covers, then put the deck back on the mower. Don’t remember how the belt fits? There should be a diagram on the top of the deck.
Getting the Right Spindle for Your Cub Cadet
www.cubparts.com isn’t just an online parts warehouse, we’re a certified Cub Cadet dealer. Our site has factory descriptions and parts diagrams to find the OEM replacement you need to get your mower working again, whether you need a new spindle assembly or just a new blade bolt. We ship to the United States and Canada.