Guidance for replacing spindle bearings on Tiger Cub

[aggiejet]

My local Scag dealer will no longer rebuild (replace bearing and seals) in my Tiger Cub spindle so I thought I might attempt it myself as opposed to buying a new $250 spindle. However, my first attempt at removing the spindle nut proved futile. I am using a 1/2” impact gun on the nut, but I can’t keep the spindle from spinning while clamped in the jaws of a 4” vise.

So is there a technique for removing the spindle nut beyond the obvious ( bigger vise and impact)? Additionally, what is the torque for installation of the new bearings?

 

[bertsmobile1]

The usual method is to take the pulley bolt off first while holding the blade then pull the spindle out leaving the blade on the spindle
Unless they bearings are heat shrunk into the housing ( heat the housing & chill the bearings ) there are only so many times you can replace the bearings before there is too much wear and the bearing will not be held secure enough in the housing
As for the blade retainer, they self tighten in use particularly if you do not keep the blades sharp
I often have to cut the heads off after which they will undo with my fingers .
Round things need to be held in a pipe clamp or between a pair of V blocks

 

[StarTech]

You would need a thin wall impact socket. I believe I use a 12 point 1-1/2" deep well socket here but it has been a few year since my last rebuild of one these as I can get Oregon 82-325 spindles as low if not lower then the parts alone. You also need a long punch and heavy to drive out the bearing cups and Approiate OD sized socket to drive the cups back in. And of course wheel bearing grease. EP2.

For each spindle you would need:
481024 upper seal (35UC05)
481025 lower seal (Rotary 13523)
481022 taper bearing and cup set, 2 each (L44649/l44610)

And possibly the spindle shaft 43589 and the nut 481035, Reason being the threads on the lower side gets damaged from mowing.

From a shop view point it is less time consuming and more profitable to install the after market spindles.

 

[aggiejet]

You would need a thin wall impact socket. I believe I use a 12 point 1-1/2" deep well socket here but it has been a few year since my last rebuild of one these as I can get Oregon 82-325 spindles as low if not lower then the parts alone. You also need a long punch and heavy to drive out the bearing cups and Approiate OD sized socket to drive the cups back in. And of course wheel bearing grease. EP2.

For each spindle you would need:
481024 upper seal (35UC05)
481025 lower seal (Rotary 13523)
481022 taper bearing and cup set, 2 each (L44649/l44610)

And possibly the spindle shaft 43589 and the nut 481035, Reason being the threads on the lower side gets damaged from mowing.

From a shop view point it is less time consuming and more profitable to install the after market spindles.
View attachment 65399

Thanks for the replies. Good idea about V block. I also didn’t give the race replacement much thought. That would be a challenge as well. Just seems a waste not to “just“ replace the bearings, but it appears to be a much larger task than I envisioned.

I have gotten about 1200 hours out of my original spindle bearings. What kind of life are you getting with the Oregon brand? Do you know what brand of bearings they use?

 

[bertsmobile1]

Fortunately most tapered roller bearings are fairly good.
I have a lot of old 2000 & 3000 series Cubs that also use the correct bearing for blade spindles, tapered rollers .
When they get a little slack I take a few thou off the spacer.
To date the only actual bearings replaced were off a couple of mowers where the owners never greased them
Down side is of course the spacers will need to be replaced when new bearings are fitted but on these housing the bearings should last almost forever .

The shop up the road replaces the bearings when they get the slightest wear because he does not machine the spacer so he can not take up the wear .
Think about wheel bearings , you just keep repacking them and nipping up the bolts till you get significant grooves in the cups .

 

[aggiejet]

The usual method is to take the pulley bolt off first while holding the blade then pull the spindle out leaving the blade on the spindle
Unless they bearings are heat shrunk into the housing ( heat the housing & chill the bearings ) there are only so many times you can replace the bearings before there is too much wear and the bearing will not be held secure enough in the housing
As for the blade retainer, they self tighten in use particularly if you do not keep the blades sharp
I often have to cut the heads off after which they will undo with my fingers .
Round things need to be held in a pipe clamp or between a pair of V blocks

I’m not sure what you mean by “pulley bolt”? The belt pulley is held in place by a tapered collar, which uses two 1/4”x1” bolts to attach it to the pulley.

 

[StarTech]

I’m not sure what you mean by “pulley bolt”? The belt pulley is held in place by a tapered collar, which uses two 1/4”x1” bolts to attach it to the pulley.

It just Bert throwing something out without even looking up the mower. Assuming things will get you into trouble at times. This is why I normally need the equipment actual model number so I can look it before responding. Just too many designs to remember everything.

Those same screws are used to remove the pulley pressing out the tapered collar. Personally I recommend those 1/4" cap screws be grade 8 rated. Even then those collars can be a little stubborn about coming out.

 

[aggiejet]

It just Bert throwing something out without even looking up the mower. Assuming things will get you into trouble at times. This is why I normally need the equipment actual model number so I can look it before responding. Just too many designs to remember everything.

Those same screws are used to remove the pulley pressing out the tapered collar. Personally I recommend those 1/4" cap screws be grade 8 rated. Even then those collars can be a little stubborn about coming out.

Not only grade 8, but fresh new grade 8. I twisted both of mine off removing the right spindle last week. But mine are the originals and about 20 years/1200 hours old. I’m sure they’re a little fatigued. I’m working on making a YouTube of it in an effort to save somebody a little frustration.

 

[bertsmobile1]

It just Bert throwing something out without even looking up the mower. Assuming things will get you into trouble at times. This is why I normally need the equipment actual model number so I can look it before responding. Just too many designs to remember everything.

Those same screws are used to remove the pulley pressing out the tapered collar. Personally I recommend those 1/4" cap screws be grade 8 rated. Even then those collars can be a little stubborn about coming out.

Guilty as charged
Memory is not what it used to be .
However the tip about shortening the inner spacer still holds
The outer races are a problem because they are really difficult to knock out .
It is SOP for tapered rollers where the bearing cones do not have adjusters
Some gear ( not mowers ) use shims to set the bearing preload

 

[aggiejet]

update :
I was able to disassemble the hub today. I soaked the spindle nut in Kroil for a couple of days and then today heated the nut and spindle with a hand held Mapp gas torch. Used a pipe wrench on opposite end of nut and used a standard 1 1/2” socket on 1/2” impact and nut came right off. Threads on spindle are in good shape.

I was only able to remove the race for the top bearing. The bottom bearing race does not display enough of a lip to get a bite with any punch or chisel I have.

I understand why nobody rebuilds these hubs now. It seems to me that the above mentioned race is not removable, and therefore most shops rebuilding one probably just replaces the bearings only. That’s really not a proper repair.

I also base my assumptions on the dearth of information regarding spindle rebuild guidance. That said, I’m looking for a torque value for the spindle nut. I’ve messaged Scag for the info and of course they haven’t replied.

I’m on a mission now. Keep ya posted.