grinds in neutral

[waterman74]

I just bought what I believe is a 51" 8n (serial # not readable). While tractor is idling in neutral or while in gear there is a slight, sort high pitch grinding coming from transmission/ clutch area. Any clues anyone?

 

[ZANE]

Probably some worn transmission bearing/s. My 8N has done it since I bought it dead and got it going again. If I ever break it apart at the front of the transmission I will replace the input bearing there. Make sure the drive train oil is not real milky looking meaning water in the oil. That is bad on everything including the lift and rear end as well as the transmission.

Zane

 

[Bruce (VA)]

Tractor in neutral, clutch out, is it making the noise? When you put the clutch in, does it still do it?
50 Tips

 

[waterman74]

with the clutch out it does it in neutral or in any gear. with clutch in it does not make the noise. i was thinking a throw out bearing? not sure, my first tractor, but I already love it. my 2 year old too.

 

[waterman74]

tranny fluid looks brand new, noise not real loud, and not clunking, but there is defiantly a grinding noise going on, other than that it seems to run fine, any threat of doing real damage if it isn't fixed right away?

 

[Bob]

If the noise continues with the clutch pedal "DOWN" (disengaged) AND the tranny in gear it sounds like a throwout bearing/lack of clutch free travel problem.

If it only occurs with the clutch pedal "UP" (engaged), transmission in gear or not, it sounds like a transmission input bearing or countershaft bearing. Is there any type of auxiliary transmission ahead of the main transmission?

 

[Jim(S.E.Mich)]

The only time the throwout bearing touches anything or rotates is if the clutch is in(engaged).
When the clutch is out the throwout bearing should not be touching anything and therefore will not be rotating or moving. (If the clutch is properly adjusted.
Probably a bearing in the transmission.

 

[waterman74]

when the pedal is pushed down, isn't that engaged? or am I backward? anyway with tractor not moving but running in neutral, or when in gear and rolling regardless of gear, is when the noise is heard. when clutch is pushed down (changing gears), is when it stops?

 

[waterman74]

tractor is (stock) as far as i can tell, 4 forward and 1 rev

 

[Bob]

Depressing the clutch pedal disengages the clutch.

You say depressing the clutch STOPS the noise, so that would rule out a bad TO bearing and indicate a bad transmission bearing.

Since it makes the noise with the tranny running, even if not moving, that would indicate an input shaft bearing, mainshaft pilot bearing or one of the countershaft bearings.

Based on your description, the bearing(s) most likely to cause the noise are circled in green.

<img src = "http://i167.photobucket.com/albums/u125/27Grainfield/N%20Ford/NoisyBearings8N.jpg">

 

[waterman74]

ok to run for a while? or does need attention right away? looks like a pretty major fix.

 

[Bob]

Hard to tell.

OBVIOUSLY not a good thing, but if it's not rapidly getting worse AND there's no/few filings in the oil, it MAY work for YEARS of light-duty with no problems.

OR, if the bearing wear is bad enough, it may start to damage the gear teeth from the shaft(s) running outside of their intended centerline.

 

[Bob Harvey]

I'll go with your first guess - throw-out brg. Pedal down it is under pressure (clutch disengaged), pedal up (clutch engaged) free wheeling and .......

 

[Dell (WA)]

Waterman......as pointed out, it aint'chur throwout bearing and most likely yer tranny input bearing, not difficult to replace, but you haffta "split" yer tractor. Its NOT going to damage ennythang as long as you keep yer 5-gals of hydro-tranny full. (full is the bottom bolthole in yer 6"-roundy round dipstick plate behind yer right heel, PULL to check. Don't trust yer dipstick) Too full and yer pumpin' hydraulic fluid out yer axle trumpet mouths and greesin' yer brakes. NOT GOOD ......Dell

 

[Hobo,NC]

I would fix it (transmission problem),,, they normally do not make noise,,, if they do its tell'n ya sum'n,, are wait till all ell tears up (you will here it then) your call... New oil is not gonna fix it... Bob gave ya some good free advice,,, listen to'em

WARNING :shock: all I know I read on the Internet,,, do it enuff and you can become a guru also,,, not responsible for damages,,, I read it and just pass it along,,, proceed with caution

 

[Greybeard - PA]

Remember, we're dealing with 60+ year old parts here. That transmission input shaft bearing that is making your noise is the one bearing in the gear box that turns ALL the time the engine is running and the clutch pedal is up, so it gets more wear than the rest of the tranny bearings. Stands to reason that during all those years of service the oil level likely was allowed to get low - the most logical cause of bearing failure.

If you do replace the input shaft bearing, you should know that there are two available - a standard duty and a heavy duty type. Go for the better of the two if you have a choice. See John Smith's Old Ford Tractor web site ror part numbers on the two bearings.

Good Luck

 

[Bob]

Beard,

The statement you posted "That transmission input shaft bearing that is making your noise is the one bearing in the gear box that turns ALL the time" is NOT true.

There are FOUR bearings in an 8N transmission that are wearing at all times the engine is running and the clutch is engaged, NOT just the input bearing. They are the ones I circled in the diagram.

The input (pilot shaft) is turning and constantly drives the countershaft (lower shaft). If that were not true the PTO would not work unless the tractor was MOVING.

Here's the drawing again, to refresh your memory:

<img src = "http://i167.photobucket.com/albums/u125/27Grainfield/N%20Ford/NoisyBearings8N.jpg">

The gear at the rear of the input shaft (Key #1) is in constant mesh with the gear (Key #25) at the front of the countershaft.

 

[waterman74]

Sorry to bring back a dead thread, but I'm looking at splitting the tractor to fix this bearing issue. I think splitting the tractor is covered in these and other forums. What I'd like to know are specifics in removing these shafts and bearings, and what other parts to check or replace while I'm in there. Thanks