Very basic operating question: Grinding gears

[amashinga]

Hi,

I have a small Ford 1100 tractor. I am moving a lot of roadboase which requires frequent shifting between 3rd and reverse. I have noticed some gear grinding sometimes moreso than others. Rather than simply assuming something is wrong, I was wondering if this could be operator error.

The first issue, I noticed that if there was a heavy load on the hydraulics, the gear grinding was worse, I simply solved that by avoiding those situations.

The second part of this, I typically change without down revving at all. Is this SOP, or is it a dumb thing to do ?. Should I be dropping down from operating rev's, changing, and then shifting up again ?

Thanks
Bruce

 

[oosik]

I had a small Ford 4WD tractor - 1700. The only thing that caused gear grinding on the Ford was shifting too fast from a forward to reverse gear. The tractor must come to a complete stop before you do any shifting. The engine rpm should have no bearing on the gears grinding. The heavy load on the hydraulics (bucket full of something) is only a factor in that it causes the tractor to continue to roll after you push in the clutch. The gears will grind every time if you attempt a rapid shift from forward to reverse. The gears in the tranny must come to a stop before this shift is made. If this does not work then you may need to make an adjustment in the clutch linkage. Your owners manual should tell how to adjust the clutch linkage.

 

[strum456]

If traveling forward, stop completely THEN move the shifter from whatever forward gear to reverse. RPMs can definitely cause gear grinding if there is any clutch drag at all. In some situations, high RPMS can cause grinding, even if the clutch is working properly. See below

Picture this. Engine::Clutch::in-Transmission-out::Rear axle and tires

Grinding is generally caused by 3 things:

1:
If you take the tractor out of gear before stopping, the tires will cause the output side of your trans to rotate until the tires stop moving. This can cause grinding if you try to switch gears before stopping because the input (clutch side) of the transmission may be rotating at a different speed than the output.

2:
On the clutch side, if you take the transmission out of gear before stopping, the clutch and and transmission input shaft will continue rotating due to rotational momentum (these parts rotate at engine speed). The higher your engine RPMs, the more momentum on the clutch and input shaft, and therefore more grinding. To avoid this, stop the tractor completely, then take the trans out of one gear, into neutral and to the next gear. By stopping with the trans still in gear, this maintains a connection with the rear tires. When the rear tires stop, they stop the entire drive line with them all the way to the clutch. This eliminates the rotational momentum that would cause grinding.

3:
Clutch drag. This may be due to improper adjustment or rust buildup on the flywheel from long periods of non-use. To check for clutch drag, put the tractor in gear as normal. While holding the clutch in the whole way, take the tractor out of gear for about 5 seconds and then put the transmission back into gear. If the gears grind, your clutch is dragging.

All info above is for non-synchronized transmissions. Newer, synchronized trannys will be different in a couple ways. I won't get into it, because I don't think syncros apply to the OP's question.

 

[crashz]

My guess is that you will recognize at least one of the reasons above.

My 770 is a collar shift, and when i do loader work i tend to grind once in a while. It stems from shifting out of gear before stopping fully. Trying to go to fast. Used to shuttle shifts on wheel loaders.

 

[Grandad4]

Many compact tractors lack a synchronized transmission. You pick a gear and you're not expected to be shifting to another gear without coming to a full, dead stop first. There is a lot of gear reduction in a tractor transmission, so even a little movement of the wheels can prompt grinding when you shift. It's possible to double clutch when shifting, which supposedly gets the gears spinning enough so they don't grind, but it takes more skill than I ever had to make it work.