I replaced all of the steering components on my WH 312-8 at about 1,000 hours last year. This included a new steering shaft and pinion, steering sector and shaft, tie rods, spindles, and wheel assemblies with ball bearings. The original spindles were still good but since I increased the front wheel size, I needed shorter spindles in order to keep the tractor level.

Each new component took out some slop. The new tie rods took out the most. My tractor now has extremely tight steering.

-Deerslayer

One thing to be aware of is that if you use roller bearings for wheels, you really should have a separate bearing, or other method to take up the the thrust loads (which are pretty high on a tractor). With the bushing setup, they do it with just the flange on the axel and the wheel retaining washer, but if you are trying to improve the system, that isn't a very good way to do it, plus the derbis from wear on the thrust surface may get into the roller bearing. This is why they use ball bearings with moderate thrust load capabilities on wheels, plus they are a lot easier to seal. By far the best for wheel bearings is tapered rollers, but that is probably overkill for a lawn tractor.

The WH 520 has roller bearings in the front wheels. The inside bearing has a seal with a spacer between it and the spindle flange. The outide bearing has simply a washer. The spindles are threaded and accept a slotted nut/cotter pin for precise bearing adjustment. The hubs have metal dust caps to keep out debris.

-Deerslayer

Deerslayer: I have never seen a WH520, but you say "inside" bearing, so I assume it has two bearings per wheel. Are they straight or tapered? The fact that you said there is an adjusting nut would imply tapered, which is, as I said, the best around. I assume the OP was talking about putting in a single, non tapered, roller bearing, which is a totally different animal, and not able to take up thrust like tapered rollers.

Tapered. Here's a drawing.

{{gwi:357802}}

-Deerslayer

My impression of butchs hobby's plan is that he wants to equip the king pins with a roller thrust bearing instead of the plain thrust washer that is used on many machines. I did not get the impression that he was referring to the wheel bearings at all. I hope he isn't intending to replace the "king pin bushings" with roller bearings.

Mownie, I agree that Butch isn't referring to wheel bearings/bushings. I was responding to Booster's posts.

-Deerslayer

10-4 deerslayer, I guess I kind of wandered away from that point. (you'd never know it but I tend to ramble sometimes). I hope everyone is having Merry Christmas morning.

I am putting roller bearings instead of the kingpin bushings and a flat needle roller bearing between the bottom of the axle and the kingpin. Everything in the steering will be roller bearing instead of bushings when I get done. The tractor came with ball bearing frt wheel bearings. I really think this will cut the steering effort almost in half. I've got 18-850-8 frt tires on the tractor and wanted to make it easier to go around these darn trees. The kingpin bearings are 3/4" ID 1"OD by 3/4" long, same bearings for the sector shaft, the bellcrank uses 7/8"ID 1 1/8"OD by 1" long. That leaves enough space in the center to leave the grease zerks where they are. The pivot bearings are 3/4" ID 1 1/4"OD by 62.5 thousnads thick, a flat harden thrust washer goes on each side of those and are available in .30"-.60"-.90" thick. I'm useing one of those at the end of the sector turn plate shaft, plenty of room for the added thicknes there but might have to have a little machined off of the bottom of the axle.

butchs hobby, my earlier remark ("I hope he isn't intending to replace the "king pin bushings" with roller bearings.") needs some explanation as to my concern with that conversion.
Will you have enough metal left over (in the spindles) after you overbore the vertical holes in order to accomodate the roller bearing assemblies that will replace the OEM bushings? You want to make sure the improvements don't weaken the basic structure of the OEM spindles. Of course, since this is a pretty ambitious project, it would not be much more of a leap if you need to lay in some weld deposit metal to restore the thickess to a satisfactory dimension. Let me caution you though, IF you need to resort to weld deposition to increase the thickness, have all the welding done BEFORE the overboring is done to the spindles. This way, any "drawing" or "warping" that occurs in the welding, will be addressed during the machining process. Also, you will not run the risk of errant weld spatter entering and bonding to the freshly machined surface in the bore (which would need to be removed before the spindle can be used). I love it when people ain't afraid to weld and/or machine. I tip my hat to you.

I'm not trying to start a silly argument, but have you ever seen a axle with needle bearings ? In short, if it worked better, surely someone would be using them.

If "ABC Outdoor Power" made a tractor using needle or roller bearings in all the places the OP intends to "retrofit", it could add $300.00 (or more) to the costs of manufacture and marketing of that machine. In today's "price point" manufacturing & marketing strategies, $300.00 is a major stumbling block for the OEM to overcome (10 stumbling blocks at $30.00 is as bad or worse). Also there is the "planned obsolescence" factor in sound manufacturing & marketing (from the OEM's perspective). If you build something that lasts "too long", your future sales of both unit assemblies AND replacement parts will suffer in the long run. A major detail in manufacturing and marketing (to offset R&D) is to price the finished product unit near, or a little bit greater than, the actual "cost per unit build" expense borne by the OEM, with additional revenue being generated from the sales of replacement parts and maintenance products. It is to this end that OEM's walk a "tightrope" of hope that enough consumers will return to the OEM network for parts and services. And what would be the gain to the OEM or the consumer to build one system (steering for example) to a greater standard of quality or endurance while leaving the rest of the product at the market median level? The marketplace will dictate that products will be built at the lowest possible cost to the OEM, but will be sold at the highest price that the consumer (collectively speaking) is willing to pay. "After sale" revenues from replacement parts, etc. is more lucrative to the OEM than the sale of the machine. If you wish to test (or contest) this, just pick any product you can think of, select 5 MAJOR replaceable parts or components from the OEM's parts list and price them. In most cases the total $ amount for those items will exceed the selling price of the entire assembled product from the OEM.

Mownie, yes I checked to make sure there was plenty of metal to allow for the bore increase. And you're right about the reason for bushings instead of bearings by the OEM. I always look for a way to improve my old tractors when something needs fixed. The spindles/kingpins themselves are worn at the top bushing area. The machine shop is going to weld that area and then remachine them which should make them like new again. I'd sure buy new ones if I could get em, but since I can't I have to go this route. The tractor is only 35 yrs old, what's a matter with those parts people? This tractor is a 1650MF that was generally thought of as too expense new, but I disagree, 35 yrs equals how many box store mowers? Original motor and hydro still work like new.

I think that most of the steering friction occurs between the front tires and the ground. Therefore, I doubt that replacing king pin bushings with roller bearings will reduce steering effort substantially on a GT. This is pure speculation on my part since I haven't done such a replacement. However, I have noticed that my steering effort is dramatically reduced when my front tires are on ice.

Butch, please post your results after the upgrade.

-Deerslayer

You may be right Deerslayer, this is something I've been thinking about doing when I realized I'd have to have the spindle/kingpins welded up and remachined because of all the wear on them where the bushing contacts them. This tractor really don't turn very hard, I'm getting spoiled after useing my 445JD with power steering and what the heck, it may help a good bit. Guess I'm in the steering improvement mode right now, I recently put p/s on my 1855MF, plan to go completely thru the steering on my 1450MF when I complete the 1650. With these frt end rebuilds it should be the last time I ever have to fool with them, they'll outlast me!