John Deere 870 weird sound

[Freedom.acres]

I recently bought a 1992 John Deere 870 it has 1300 hours on it after owning for 3 days or so and putting probably 8 hours on it i started hearing a whoooo sound accompanied by the rpm’s jumping up. It appears to be happening in all ranges and in all gears it usually happens when accelerating or putting load on the engine. Any ideas as to what it could be or things I could check. Thanks

 

[5030]

Sounds like one of the air intake hoses is loose.

 

[Freedom.acres]

I will check that for sure I’m seriously hoping for something simple as this was a large investment and am hoping to get many years of service out of this tractor

 

[Freedom.acres]

Sounds like one of the air intake hoses is loose.

Sounds like one of the air intake hoses is loose.

When you say one of the air intake hoses do mean the hose coming from air intake filter? If so that hose seams tight on both ends. Any other thoughts?

 

[Deleted member 216442]

I agree probably clutch slipping, as it is likely to do that under load causing the rpm rise. Not sure about the described sound. Removal or leaking of entire air inlet system is unlikely to change rpm much since this is a diesel engine, unless the filters are horribly clogged. I would think it'd be smoking alot if inlet was clogged. 870 has a 2 stage clutch - first half of pedal push disengages engine clutch, second half disengages pto. Check the clutch free play, and if that is up to spec, there is a little window on the side of the clutch housing with a screen you can remove and look at the thickness of the clutch disc. If you are lucky it'll be an adjustment. If not, clutch replacement requires splitting the tractor. I'd check over the whole unit to make sure all bolts on engine to clutch and transmission are tight to be sure something is not loose and throttle linkage not changing length under load. It is low hours for a clutch to go bad but not everybody is good at using clutches properly.

 

[Deleted member 216442]

Here is a link to people discussing the 870 clutch adjustments. It describes how to access the view port.

870 Dual Stage Clutch Question

Hi! JD Model 870 tractor 1994, 3500 hrs. Could someone help me understand what's going on with my dual stage clutch? Over the last year or so I've had to adjust the pedal linkage out several times in order to get the pto clutch to disengage. Now I seem to be at the limit of the adjustment...

www.greentractortalk.com

 

[Freedom.acres]

New developments it appears that the sound which I can best describe as a whine or hum almost like a tired bearing would make. I believe it is coming from the distribution box located above transmission at base of steering column. Is there a bearing or anything in there that would make a sound like that. Also not sure why it would increase tractor rpm’s. Thanks for all the support here

 

[Freedom.acres]

I agree probably clutch slipping, as it is likely to do that under load causing the rpm rise. Not sure about the described sound. Removal or leaking of entire air inlet system is unlikely to change rpm much since this is a diesel engine, unless the filters are horribly clogged. I would think it'd be smoking alot if inlet was clogged. 870 has a 2 stage clutch - first half of pedal push disengages engine clutch, second half disengages pto. Check the clutch free play, and if that is up to spec, there is a little window on the side of the clutch housing with a screen you can remove and look at the thickness of the clutch disc. If you are lucky it'll be an adjustment. If not, clutch replacement requires splitting the tractor. I'd check over the whole unit to make sure all bolts on engine to clutch and transmission are tight to be sure something is not loose and throttle linkage not changing length under load. It is low hours for a clutch to go bad but not everybody is good at using clutches properly.

The tractor makes the sound in neutral and continues making sound even if I depress clutch to the floor

 

[Freedom.acres]

Here is a video link to YouTube of the sound as I view through port in side of transmission. The tractor is in neutral at idle to start you can hear it faintly and it gets louder as I increase rpm.

 

[Deleted member 216442]

Have you measured the free play in the clutch pedal and measured or observed the thickness of the clutch plates? Why chase the sound when you can look at the working clutch parts from the side and determine if they are worn out. If sound changes when you depress the clutch it is likely something in there like the pilot bushing or bearing or whatever the 870 uses. I'd be interested in seeing an illuminated photo of what is in there with the engine stopped.

Free play is the distance the clutch pedal moves down before it feels like it is doing anything - it should be around 1/2 to 5/8". The clutch linings should not be paper thin - more like 1/4" or so.