Knocking in Rear End of Jinma 354

[cnsJohn]

I apologize for the double post in the Parts/Repair forum:

My Jinma 354 has always had a slight knock in the rear end. However, lately its been getting really loud. I can't tell if it's drive train or PTO. The knocking speeds up with the trottle and it is there regardless of whether the PTO is engaged. It only stops when the clutch is completely depressed, so it may well be PTO related. Any idea what could be causing the knock? Could it be in need of a clutch adjustment?

Just for extra info, the PTO does grind slightly when engaging; and also it does stop fully when the clutch is depressed.

Any insight is greatly appreciated.

JohnJ

 

[greg_g]

Sounds like your clutch adjustment could use a tweak, but I don't think that's the cause of the "knock". I haven't heard this complaint before, so I'd have to do a little more troubleshooting. Do you have access to a mechanic's stethoscope? It would help a lot to isolate a more specific location of this noise.

//greg//

 

[cnsJohn]

Greg,

Thank you for the reply. No I don't currently have a mechanics stethoscope, but I guess Auto Zone would loan me one. I'll give it a try. The knock is pretty loud, but the steel casing does make it difficult to determine exactly where the noice is coming from. Hopefully the stethoscope will narrow it down.

Thank you again for the reply and suggestion.

 

[RonMar]

Does it still knock when under load/running a PTO impliment? I was initially surprised by the ammount of noise my geartrain made at idle without a load on the PTO, especially when warm. The power pulses and the geartrain backlash worked together to make a very loud knocking noise. The noise is hard to localize, as the cast case really conducts well. It comes from everywhere and nowhere at the same time Once under load, the gearbox is noticeably quieter... What lube are you using in the gearbox?

If the PTO is stopping when the clutch is fully depressed, that sounds like it is pretty close to the right adjustment. Sometimes they will keep spinning a little just from the little bit of friction between disk and plates in contact, especially with no impliment attached. The drag of a PTO device is usually enough to break this friction and the impliment should coast to a complete stop with clutch all the way in.

My china tractor will occasionally grind when engaging the PTO. Especially if I don't give it enough time to come to a stop after I push in the clutch. Remember straight cut gears and no syncros so the gear teeth must be in sync/stopped to engage quietly. Due to the above mentioned disc to plate friction, without an impliment it is sometimes impossible to engage untill you stop the engine as that little bit of friction will make it seem like you have never stepped on the clutch even when it is fully depressed.

 

[fredw]

hi, i think the wristpin has end play and i hittihg on the housing, but if you depress the clutch andit doesnt do it,then I dont have an answer. fredw

 

[cnsJohn]

Ron,

Thank you for the great information. Your description sounds a lot like what I'm experiencing. I'm not sure of the lube in there now. I plan to change all fluids before I use the tractor again. Any recommendations for a good gear lube?

JohnJ

 

[fredw]

JohnJ

Im not familiar with this tractor, but if its got an inside brake system, do not use reg hydrolic fluid, use hydrolic brake fluid.Do not mix hydrolic fluids because it will cause a mess of foaming.
Fredw

 

[RonMar]

John, i am a big fan of using gear oil in gear boxes, so perhaps something along the lines of 80W90. It needs to be yellow metal friendly though. For hydraulics, I am a big fan of aw-32, simple all purpose hydraulic oil. Of course in the diesel I like Rotella-T 15W40...

 

[greg_g]

JohnJ
Im not familiar with this tractor,

Then it's not prudent to respond Fred. This is not a common sump tractor, hence conventional gear oil is specified for the gear trains; typically 80W90, or 80W140 in warm climates. Plus, the braking is mechanical, not hydraulic. This tractor employs a wet disc system.

//greg//