Simplicity 9020 PowerMax Deck Needle Bearings?

[curvecrazy]

I've got a Simplicity 9523 which is the late 70's two cylinder diesel tractor with a 60" center mount deck. This is the same deck as the Simplicity 9020 gas version, the 616, 620 etc...

My problem is my spindles. The center spindle was just shot so I replaced it with a new one $135. I also found the two side spindles to be somewhat spalled. I assume lack of greasing by the prior owner. I just bought this tractor last year.. first tractor. {smiles} So the spalling is worse on one than the other. I know the one is useable for sure and the second probably. Enough so I plan to try. Unfortunately, both of these spindles have broken dust shields and whoever worked on it before left out parts like the upper thrust bearing cup. There were springs missing from the bottoms too. And all the thrust bearings were shot in one form or another. Of the two bearing cups that were actually there, both were punched in my the careless assembly and the keys walking in the keyways and hitting the cups... making thrust bearing failure emminent. LOL

So I went to the local bearing supply for the bearings. They had the thrust bearings and washers. No problem. The upper and lower needle bearings they had are the full complement bearings. Not the caged type needle bearings that were used stock.

I've put a lot of thought into this. As to whether I can use these full complement bearings or not. They can handle the RPM's of the mower deck according to tech support at Torrington[bearing company]. According to them the full complement will probably work. The oem caged types have lower load ratings but higher RPM ratings. The caged hold grease better by design due to the spaces tweenst the needle rollers. I was sort of thinking the full complements would put less pressure on the shaft where the spalling is present and possibly work better but the tech support guy at Torrington seemed to think the opposite that the caged would be easier on the shaft due to less continuous contact. It is expected the full complement would have more drag in operation due to their design and needles on needles rotating in opposite directions.

So I am debating. Use the full complement bearings I have in hand, and grease each time I use the mower. Or hold out and buy caged needle bearings. Most would say, it was designed with the caged bearings so just go with the caged but I will have to mail order those cause nobody local has them. It is also worth noting that the bearing and metallurgy technology has come a LONG way in 30 years time. But that would apply to both needle bearing styles. I also have considered using possibly using 1/4 inch longer needle bearings than the oems to reach up the shaft a bit further past the spalled area, also greasing each time. The tech guy seemed to think either/or would work fine with consistent greasing but he said he would go with the stock bearing lengths.

I know the right way is to replace the outer spindles too but at $168 each for those I'm wincing. Anyone with experience here? Ideas on compatible arbor assemblies aftermarket or otherwise much appreciated. These are beefy arbors. I've no doubt this tractor will run forever and it mowes nice so maybe I should just spend the $700 or so for all new spindles and assemble it. fwiw

Thanks George

 

[curvecrazy]

Would also be interested if anyone has some good used arbors for these older needle bearing decks. Or even a used in good shape parts deck for sale... I'm in NYS. Thanks.

 

[curvecrazy]

For better or worse... It finally came down to me physically running the needle bearings on the spindle shafts themselves and feeling the smoothness of each of them running around my not perfect shafts. I found the longer 1" needle bearings were far smoother than the 3/4" versions. I went with the full complement bearings. Put an oversized 1" in the bottom and a 3/4" in the top of each cause the bearing seat is too shallow for a 1" at the top and the amount of modifying to make it so would have been too much. So I installed the 3/4" full complement needles on the top and instead of running them full down to the shoulder in the seat just drove them in flush with the top of the bearing hub. The idea being to have the bearings run higher than before and hopefully acting on a better shaft surface.

I need to weld back on my dust shields today cause those were both broken off by the prior owner too. I'll see how it goes but my preliminary findings show the hubs spin pretty freely with little hint of roughness on quick grease/preassemble.

Time will tell here.

Interestingly enough. It almost looks to me like the center spindle on the deck went bad and had lots of freeplay back and forth in its operation. I assume the whole thing didn't have enough grease applied and it looks like the center arbor rocking applied unequal torques on the side arbors and bearings which wore them on basically one side of the top and bottom. What I mean is, on the top of the spindle for example, the one side is mint like new and the other was spalded from the force of the rocking center arbor working that side arbor. And on the bottom of the spindle, the same phenomena but the opposite side from the top spalded area. LOL So it was getting pulled hard as the center spindle rocked in operation. This was the case on both side arbors but one is worse than the other. fwiw


Would grease have helped? Hard to say....... I don't know if he ever greased it.

Now I wonder if the belts themselves can develop loose and tight spots from say the center spindle being damaged and maybe I should replace that too??? The center spindle shaft had about .060" groove cut into the top where its spalded and the bottom probably .080" groove. That ones really cut in. So that play was the source of the rocking on the side shafts.

Anyone?

 

[mostly_gas]

I have seen a bad spot in a chain drive do the loose/tight thing but not a belt. As long as the belt is not frayed or glazed it should be OK.

 

[curvecrazy]

Upon reassembly, the belt is not slapping around and its all running smooth and quiet. Cuts nice.