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856 gear noise


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My neighbor has an 856 that has developed a noise in neutral when idling in lo or second gear. This sounds like gear clash as if you were to shift between 1-4 when the tractor is running and the range is in neutral. But the noise is not present when in third or fourth gear. This noise is when the tractor is running but not in motion. I split this tractor this spring to put in a clutch and ended up splitting it further to replace the TA as it did not work and the input splines were very poor. However this was the first time I had been into a tractor this far so I just split it and hauled it to town and the dealer did the work on the center section. I know that the speed trans is in the center section so could it be something the dealer did? The noise wasn't present when I got it back together but the tractor now has only about 200 hrs on it since the TA split. I'm assuming it would possibly be under the speed trans cover, maybe a broken roller or damaged shift fork. Any suggestions on where to start would be helpful as the dealer will not work on it unless I briong them the center. I would rather not split it that far if not necessary to. This tractor is also hard to get into low gear, it jumps out. Is it worth rebuilding the shafts that go down to shift linkage( the tie rod ends seem tight but there is some play at the trans end of the shift shaft) or would it be better to replace range trans cover, maybe with a Wenz cover. I did that on Dads 856 and it shifts very well since. Hope you guys can point me in the right direction, Thanks, Rob

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My neighbor has an 856 that has developed a noise in neutral when idling in lo or second gear. This sounds like gear clash as if you were to shift between 1-4 when the tractor is running and the range is in neutral. But the noise is not present when in third or fourth gear

First inclination is that the 3-4 shift roller has broken. That doesn't really explain the clashing noise disappearing when moving. Another possibility is that the speed transmission countershaft nut has loosened. Easy enough to check, drop the transmission bottom plate and see if the countershaft spacers are still tight. (they shouldn't turn by hand)

This tractor is also hard to get into low gear, it jumps out. Is it worth rebuilding the shafts that go down to shift linkage( the tie rod ends seem tight but there is some play at the trans end of the shift shaft) or would it be better to replace range trans cover, maybe with a Wenz cover.

By hard to get in low do you mean you have to bang the lever to get it to flip into gear?

What's a Wenz cover?

Often times the headed pins in the shift linkage will be worn. Not enough to cause problems but it does add alot of lost motion.

If the range cover is excessively worn we usually have the local machine shop install bushings.

Jim N.

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If you have lost first gear completely I would say its the lower counter shaft nut. Seems like they usually let go in first couple hundred hrs if they are going to get loose anyway, but usually they don't make much noise till they come off and the shaft moves forward enough to fall out of the rear bearing and by then first is not reachable and second will be noisy! Also there is usually a large amount of fine metal grindings going to show in the filter at about the same time. Maybe you have caught it before it moved forward. If its not the counter shaft its more than likely forks or linkage. Lifting steering column and fuel tank will allow easy access down into the slider gears etc. I hope its the external linkage because anything else is some work.

hope this helps

Ed

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Dad's 1256 lost the countershaft nut a couple of hundred hours after a new ta installation. Better check into this possibility quickly, we had to replace the countershaft and a gear or two because of that nut backing off. His tractor went blank in first gear, lo or hi side, just like it was in neutral. :(

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This tractor has use of all gears yet and its hard to say if noise goes away when moving as it has a noisy cab on it. Wenz Manufacturing rebuilds the cover for the range transmission with some improvements. They also make other IH parts improved. They're located in Nebrakska somewhere, I have the papers in the shop. If you call the old guy, be prepared to talk for a while, the last time I did, I was on the phone for close to 2 hrs! I'll check the countershaft and hope its tight and post later, Thanks , Rob

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Ed&Jim, is the basic design the same as or similar to a 1486? We got our 1486 with a supposed "new T?A" and it has a chatter/knock in all four low range gears but high range is very quiet and acts fine. Low range is noisy enough that I do not even use it as it just does'nt sound good at all. I have been trying to figure this one out, whatever is making the rattle in ours must not turn when you shift trans to High range. I just wish we would take it in before it grenades itself and gets really expensive.

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Ed&Jim, is the basic design the same as or similar to a 1486? We got our 1486 with a supposed "new T?A" and it has a chatter/knock in all four low range gears but high range is very quiet and acts fine. Low range is noisy enough that I do not even use it as it just does'nt sound good at all. I have been trying to figure this one out, whatever is making the rattle in ours must not turn when you shift trans to High range. I just wish we would take it in before it grenades itself and gets really expensive.

Get it checked out, Nick. :( Very similar basic design.

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Its my friends tractor and I can't get him motivated to do it, I KNOW there is something gone in there, the noise makes me cringe. If High first ever goes out the tractor won't get used for anything :)

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Ed&Jim, is the basic design the same as or similar to a 1486? We got our 1486 with a supposed "new T?A" and it has a chatter/knock in all four low range gears but high range is very quiet and acts fine. Low range is noisy enough that I do not even use it as it just does'nt sound good at all. I have been trying to figure this one out, whatever is making the rattle in ours must not turn when you shift trans to High range. I just wish we would take it in before it grenades itself and gets really expensive.

Check the range countershaft bearings.

Remove the hitch pump. You can then reach up into the range section and see if there is end play in the countershaft.

As long as no gears have been damaged the coumtershaft bearings can be replaced without a complete disassembly of the rear end.

Jim N.

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If I read this right your friend has a tooth or teeth off the constant mesh gear in the rear housing. Or the tapered bearing on the shaft which carries the constant mesh gear has gone bad and lost its preload. Yes,the transmissions on those tractors are very similar. Seemed like IH just stayed with the same setup and made minor improvements as they increased HP. I think this noise is in the rear housing.

The speed trans is up front in the center housing along with the TA if tractor is so equipped. If the noise changed when using different gears of the one through four selector I would suggest gears in speed trans.

The Hi/Lo and Reverse gears are in the front area of the REAR housing. When tractor is in High Range the power comes straight in on the pinion shaft and goes straight to the differential, when in lo range the power drops down to the lower counter shaft via the constant mesh gear and then comes back up to the pinion shaft through some other gears. This gives the slower speeds of the Lo Range. This is also where most noises from Lo range are created. When using HIGH range there is no load on the gears of the lo range and they are usually quite but they are rotating.

I will be interested to see what Jims diagnosis is. One thing for sure, putting off fixing it is a good way to create lots more demand for Parts! And the labor is about 20 hours because it is the last gear to come out of the rearend.

Hope this helps.

ED

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Thank you fellas for your replies, I think if I am reading this correctly that you are both on the same page about our problem and it makes perfect sense to me the way you described it, light load or little load on the countershaft causing no noise in Hi range but when you load it, it "talks". If you change the gear you are in when in low range it speeds up or slows down appropriately, shift to Hi range and there is no noise in any gear 1-4. I think if I tell him it's 20 hours labor if it destroys itself maybe we can get it fixed this winter before that happens. I like preventive maintenance when possible, it's cheaper and simpler. Thaks again guys, you have been a great help :)

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I finally got it into the shop and removed the lower cover and could not move the spacers on the copuntershaft, so I lifted the cab and fuel tank enough to remove the trans cover.Under there the shift rollers were there and in good shape. So after furthe review, I found that the 3-4 shift fork is cracked on both sides and bent some. I am hoping this is the problem, although in my search I noticed that the 3-4 gear seems to have a fair amount of play on the splines. If yo were to move the gear front to back on the top oof the gear, it moves probably at least a 1/16 of an inch in either direction, forward or back. I wonder if this gear should also be replaced? Dealer says 600 bucks and doesn't have one although he has two forks on the shelf. Is this just a fatigue issue, the tractor has 10500 hrs on it and trans has never been apart until the TA replacement 200 hrs ago? Is the 3-4 gear supposed to have tapered splines on the inside where it meshes with the gear on the rear of the TA? This one the splines look pretty flat ended, and blunt. Also the shift cam seems plenty loose in the cover, but I'm not sure if this would cause the noise in conjunction with the bent fork ( too many loose parts) ? I was just wondering if anyone else has had experience with this stuff? Thanks, Rob

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Start with rebuilt shift cover, Probably the detent arm and roller under shift cam worn and shaft worn also. The gears are going to seem loose with that many hours, hard to say for sure how bad yours are for sure via the internet.Get your fork replaced and make sure those screws get pounded down on the edges of the shift shafts so they don't come loose.(I always use new screws) Use grease on the rollers, it helps so they don't get knocked off when installing cover. I put the cover in fourth gear position and tranny gears when installing Good Luck.... This isn't fun with that cab in your way is it!!!!!!

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I replaced the 4 speed cover wityh a reman HyCap and a new shaft. the detent roller was replaced when TA was installed. The new fork must have fixed it as the noise is gone. Its getting easier to work on these tractors as I learn a few shortcuts, like not removing the cab completely, just lifting it enough to get at shift cover(cab pivots at back). I didn't want to take this apart the second time, but it turns out it wasn't anything I or the dealer did, and this is how to get a little knowledge and experience. Thanks for the help, Rob

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