Mowing NH 930B 72" Rear Mount Finish Mower

[The Haymaker]

Back to the original thread, I'm curious. What is the actual failure on the spindle? Is it bearing surfaces or something else?

 

[Welshman]

Back to the original thread, I'm curious. What is the actual failure on the spindle? Is it bearing surfaces or something else?

Originally, the bearings failed on the right side spindle. After the bearings, seals and shaft were replaced, the spindle loosened up rather quickly. I believed, at that point that the preload was not set properly. Since the dealer was doing the work, I only know what they told me. The spindle "loosened" four more times, before they replaced the complete spindle assembly, and so far, no problem with it. The dealer told me that the bearings and seals were replaced each time, and he thought that perhaps the lock nut was "walking up" the spindle threads. I removed the spindle assembly four of the five times, and each time the tabbed lock washer was securing the lock nut, and the nut seemed to fit the shaft properly.
As I mentioned earlier, the manual states the preload should be reset every 100 hrs. of operation - I can't get anywhere near that.

I emailed New Holland Thursday, and told them I didn't think it was right that they would discontinue parts on a two year old piece of equipment, and asked if they would resolve this issue for me. So far, no response.

I haven't had a chance to view your other videos yet, but am looking forward to it.

 

[The Haymaker]

That blows. I'd start harassing New Holland about the change simply because, to me, upgrading a part on a 2 year old piece of equipment would be for only two reasons. They made a slight change so it would work in another piece of equipment to drop mfg. costs, or there was an obvious design flaw in the first version so they revised it. Any car or bike I have ever worked on has been that case. For instance, the clutch bushing and oil seal on a y2k XR650R dirtbike. Both were prone to fail easily, quickly, on the first two years of the bike.

If you had a good shape spindle to compare, I'd be curious of two items. The diameter of the spindle at the bearing locations, and the length of whatever maintains bearing spacing. If the bearings were ever preloaded to heavily, it'd push the inner races towards each other. But, that wouldn't explain the first failure unless it was overdone at the factory. Was the original shaft blued from a high heat condition?

I find it hard to believe too much belt tension would cause a premature failure. A chain drive yes, but seems to me a belt jus wouldn't be capable. I could be wrong though, done it many times. Trouble shooting is tough when doing it over the net!

Suppose I should get my butt to studying for my written exam tomorrow.....

 

[Welshman]

That blows. I'd start harassing New Holland about the change simply because, to me, upgrading a part on a 2 year old piece of equipment would be for only two reasons. They made a slight change so it would work in another piece of equipment to drop mfg. costs, or there was an obvious design flaw in the first version so they revised it. Any car or bike I have ever worked on has been that case. For instance, the clutch bushing and oil seal on a y2k XR650R dirtbike. Both were prone to fail easily, quickly, on the first two years of the bike.

If you had a good shape spindle to compare, I'd be curious of two items. The diameter of the spindle at the bearing locations, and the length of whatever maintains bearing spacing. If the bearings were ever preloaded to heavily, it'd push the inner races towards each other. But, that wouldn't explain the first failure unless it was overdone at the factory. Was the original shaft blued from a high heat condition?

I find it hard to believe too much belt tension would cause a premature failure. A chain drive yes, but seems to me a belt jus wouldn't be capable. I could be wrong though, done it many times. Trouble shooting is tough when doing it over the net!

Suppose I should get my butt to studying for my written exam tomorrow.....

I'm confident that the first failure was from too much belt tension. It was REALLY tight, and the belt is thick enough not to stretch appreciably. I disassembled the spindle, and the bearings were shot. After that first failure, I can't say for sure whether or not the bearings were bad, or if the dealer just replaced them to be on the safe side, or for that matter, if they actually replaced them (I only got one set back). In the "old" spindle, the bearings are spaced by means of steps in the housing. The "new" spindle has an actual bearing spacer - which I think is a better set-up. According to the manual, you preload the "old" bearings by tightening the lock nut until the spindle binds, the loosen just enough for it to turn freely. Interestingly, there is no service sheet with the "new" spindle to indicate the procedure or torque spec. The dealer told me that NH "doesn't have any info on it" (this was one of the questions I just asked NH in my email).
I suspect these new spindles will hold up. If I don't have any further trouble out of the two I have now, I will replace the third over the winter. By the way, I agree with your "two reasons" to redesign the spindle, and since the new one costs over $100.00 ea. more - that points to the other reason.

What exam are you taking?

 

[The Haymaker]

It frustrating to see the mixed responses from NH. SO FAR they have been excellent when I have needed them, which was for a faulty filter bracket, a cracked fender pan on a TZ25, and a brake cable that broke the second use on my T2220. The one issue I have had was being told that a regular HST filter would take the temps here in Maine, yet EXPLODED the first 20f morning. They wouldn't help with the 35.00 filter or 4 gallons of oil that rot proofed my shed floor. That was a local dealer issue though, not NH.

The written is round one of the National Truck Driving Championships here in Pittsburgh. I'm stuck here until Sunday AM.

 

[Welshman]

Rayrla - if you're still out there - how much time does it take you to mow, and how often do you mow (weekly?)?

Haymaker - I was looking at the parts break-down for your mower on the NH site. What tensions the belt? That is just one humongous belt, isn't it?

 

[Rayrla]

Rayrla - if you're still out there - how much time does it take you to mow, and how often do you mow (weekly?)?

Haymaker - I was looking at the parts break-down for your mower on the NH site. What tensions the belt? That is just one humongous belt, isn't it?

Currently with my 930B mower, I cut three sections of my property. Section 1 takes about 5 hours to cut and is cut every 2-3 weeks. Section 2 takes about 3 hours and is cut every 7-10 days. Section 3 takes about 2 hours and is cut every two weeks. Mowing season with the 930B generally starts toward the end of May and lasts until the beginning of October.
Two days ago, I replaced the belt. The center blade was not cutting very well. The belt was worn and needed to be replaced. It measured slightly less than 122". I toyed with the idea of buying a correct length Gates belt, but used the new CNH spare belt that I had. Replacement belt seemed tight, but not overly tight. Spindles appeared to be okay. Still don't understand why you are having belt related problems.

 

[Welshman]

Still don't understand why you are having belt related problems.

I sure don't either, but maybe this is more of a spindle issue than a belt issue. Interesting point: now that I have two new style spindles on the mower, the belt tension got a little tighter (at the same spring length), which I think tells me the new pulleys are a hair larger diameter. Do me another favor - even if it's over the winter. When you have your covers off again, measure the distances between the center points of the spindle pulleys, and also between the centers of the middle spindle pulley, and the fixed idler pulley. Please don't make a special point of this, because I feel I've imposed too much on you already.
I've sent a second request to NH without so much as an acknowledgement.

 

[The Haymaker]

I haven't ;ppked at the parts fiche, but the manual makes me think it has two belts. One from gbox to center pulley, then another to drive the three pulleys. Tension is same as yours, manual. Blech......

 

[Rayrla]

I sure don't either, but maybe this is more of a spindle issue than a belt issue. Interesting point: now that I have two new style spindles on the mower, the belt tension got a little tighter (at the same spring length), which I think tells me the new pulleys are a hair larger diameter. Do me another favor - even if it's over the winter. When you have your covers off again, measure the distances between the center points of the spindle pulleys, and also between the centers of the middle spindle pulley, and the fixed idler pulley. Please don't make a special point of this, because I feel I've imposed too much on you already.
I've sent a second request to NH without so much as an acknowledgement.

Will do. Within the next 3-4 weeks should have the covers off again. You previously mentioned that you removed the pulleys from the spindles with a puller and broke out a piece of one pulley. Could the pulleys be pressed out of the spindles instead?