Spindle bearings
 

Anyone ever try machining a ST 745 spindle & housing out to accept a standard bearing? My son in law loves a challenge so I threw that out to him. Is seems like it should be a fairly easy modification, the hardest part will be getting the balls out to separate the shaft & housing. I figure a die grinder will cut a slot to roll the balls out one at a time.

Once they are apart the shaft should be an easy turn down to fit a bearing on and the inside of the housing turned out to fit a bearing plus a snap ring groove to hold everything together.

With the price of the spindle assembly anywhere from $85 - $180 I think it may be a good alternative if Tom can machine it. Even if I have to spend $20 for each bearing I will be money ahead. The spindles are one step from scrap so I really don't have anything to loose.

It works on paper!!

Greg

I don't know what a ST-745 is..... :bigthink:
Is it the deck model? It doesn't come up in the parts books......

An ST-745 appears to be a special bearing assembly used on the 38, 38A, 38C, 42, 44, 44A, 44C, 50, 50A & 50C decks for the spindle bearings. It looks to be a pair of ball bearings packaged into one case. I attached a picture off the web. A neat feature of this assembly is that you grease it from the top and the grease is dispersed into the interior cavity to both bearings.

Given the vast number of bearings out there, there stands a good chance a bearing that fits the OD/ID and overall construction (ball bearing-type) characteristics exists. A collar would need to be sourced to obtain the correct spacing for the bearings, but there again, something probably exists that would fit the application.

I have to do this to my deck before mowing season starts - it's an interesting situation. Do you spend the money up front for the bearings to save time in the end, or save the money up front to spend more time finding/applying a different solution? Either way should yield the same results (in theory).

I'd just get an older style hub that uses the tapered cup/cone and never worry about it again. :bigthink::biggrin2::biggrin2:

Around here parts used parts are starting to dry up and many of the people that have some treat them (and price them) like Gold.
One guy wanted $55. for a USED Kohler carb that was painted to give the illusion of rebuilt. And BOTH of my decks (42 & 50) take this style, The 42" spindles are shot, the 50 is not too bad yet.
If I have to I will but new spindles, but this looks like it may work. If so We may be on the way to a new venture!!! I'm sure the money will just roll in by truckload:bigeyes: I also have a few used bridges and Ocean view property in South Dakota for sale also!

Greg

I've had the same thoughts. Cut the old outer race, heat the spindle to remove the hardness, and turn the spindle to accept the new bearings, leaving a land between the new bearings to hold it in place. I'm going to try it when I get time.
Richard

I snooped around a bit more on the interwebs and found the attached picture on another site. The ST-745 is on the bottom with two other bare spindles pictured. Also found was a service kit sheet for the spindles in the attached picture.

Given the thread size for the top nut probably wouldn't be a goofy size due to it's age (read: its too old for a strange SAE or Metric thread) and seeing that the OD of the shaft itself LOOKS darn close to the major diameter of the threads, a slight modification just might do the trick to the use of other bearings.

I'm curious what you come up with Greg. This discussion is veering me towards what your doing instead of buying the new big bearings or swapping out the housings.

Tom took one this morning, he said he's going to play with it at work this week and see what happens. I'll let you guys know what happens.

Greg

I talked to Tom yesterday, He did get the first "Prototype" done. He said the shaft is "Super hard" and could only take a .005" cut at a time on the lathe and the lathe had all it could do to get through it. He said it is a little tighter than he would like, but should be fine.

I'm sending the other 2 spindles up with the granddaughter today. I'll see if he can get a few pictures of them before they go together.

Greg

Greg, might see if he will just make a new shaft. He has one to go off of, and it may take less time. Just a thought. :bigthink:

Since he is a plant mechanic I know he is somewhat limited on what he has for machines. I don't know if he can cut a key way or not. I guess that this started as a challenge and turned into an experiment. If he can find a cost efficient way to rebuild over replacing these spindles.
I really can't believe that someone hasn't come up with a system to rebuild or replace these. If you figure $150 for a new spindle, if all 3 are bad, you are at $450. how much is a deck really worth? I have not done any measuring to see if any of the new style spindles would fit. add in the out dated blades (odd sized & hard to find) and it may be next to impossible to find a reasonably priced alternative.

Greg

How little of a lathe is he using? What is he using for tooling?

I went through the same thing last month. After cutting the race off, sourcing the bearings, and costing the machine work it ended up close to 500.00. so I trashed that idea.

I did find a guy who has a set of (3) NOS spindle bearings, but he wanted 140 per unit, and like previously said is it worth it? never mind having to find replacements in the future. Trashed that idea.

I did what J-Mech said, I was able to find some of the 48" cast housings. Just know that they aren't the same as the 38/42" decks, and the spindles shafts are different too.
Mike

Not sure of the exact size, but I do know that they turn some large rollers on it. He works in a corrugated cardboard plant so it's not just a little bench top lathe.

Greg