HST squeal

[iwh1952]

Hi folks,
I unknowingly put this in the intro and got no response so I'll try again here. I have a 1994 New Holland 1620, 4wd, HST w/less than 1400 hrs. When starting out there is a squeal near the transmission. When in 4wd it is very noisy and just tonight, I noticed it doing the squealing in 2wd a little. When in 4wd it is very bad. the squeal sounds like an electric motor w/dry bearing and I know that's bad, so this can't be good. The noise starts out as I put pressure on the pedal to move and does it in forward and reverse until the tractor has been used for a few min. then it stops and all seems ok. Does anyone have a clue as to what this noise may be? Any help would be greatly appreciated.

 

[jinman]

Look at your 4wd driveline going to the front differential. If it is low on lube or rubbing on the protective cover, it will squeal like that. Lube up everything well and see if things improve. Your problem might be the transmission, but the most likely culprit is the driveline rubbing or needing lubed.

 

[iwh1952]

jinman
Thanks, I will check things as you said. You may have something. I had all lubs changed last year and right after I noticed front left axle leaking on floor of garage. I haven't noticed any lub leak there in quite some time. Will be checking.

 

[Halftrack]

Let's do a little more analyzing of the problem. Is it occurring only during cold weather or year round? If year round, I agree its probably a lube problem. If it is a cold weather problem, let's consider the HST. Next time you start the tractor, put the range selector in neutral and press the pedal and see if the squeal is there. If so then the pump is telling you it is not getting oil and complaining about it. If this is the case, extend your warm up time, run both pto's during warm up, depress your pedal slightly and put the cruise on, and if you have one, cover the oil cooler in front of the radiator. The other solution is a tranny drain and refill with winter grade tranny oil. NH 134 should be replaced with NH F200. A magnetic heater stuck on the transmission might also be a consideration. Let us know what works. And WELCOME to the group.

 

[jinman]

Halftrack, your points are absolutely valid, so don't think I am disagreeing. I was considering that the OP described his symptoms as "squeals" instead of "whines." Certainly, if the squeal was an HST charge pump, it would be heard all the time. Cold operation can sure also cause a loud whine if the oil is cold and the HST is working hard to pump sufficient fluid. What caught my attention was the description of the noise as a squeal. If, in fact the noise is a whine, then the HST operating cold is the most suspect.

 

[dqdave1]

The plastic tube around my front driveshaft will squeal if you don't keep it lubed

 

[iwh1952]

Glad to be here. Will do, Halftrack but gotta copy everything down to remember.been sorta busy lately putting furnace in barn.

Let's do a little more analyzing of the problem. Is it occurring only during cold weather or year round? If year round, I agree its probably a lube problem. If it is a cold weather problem, let's consider the HST. Next time you start the tractor, put the range selector in neutral and press the pedal and see if the squeal is there. If so then the pump is telling you it is not getting oil and complaining about it. If this is the case, extend your warm up time, run both pto's during warm up, depress your pedal slightly and put the cruise on, and if you have one, cover the oil cooler in front of the radiator. The other solution is a tranny drain and refill with winter grade tranny oil. NH 134 should be replaced with NH F200. A magnetic heater stuck on the transmission might also be a consideration. Let us know what works. And WELCOME to the group.

 

[iwh1952]

Well Guys, it's -2 here so I can definitely check cold weather situations.

 

[iwh1952]

Ok guys your directions have put me on to something, not sure exactly what yet. Temps around 0 and I climbed under the tractor to look at the front drive shaft. What I found was some indications of rust where the shaft comes out of the casing. Decided to spray some lithium grease around the shaft and have yet to hear the sound. My question would be, why? I don't know yet but I seem to have it narrowed to the output shaft. thanks bunches for assistance, will post again as to the outcome. thanks again. W.

 

[jinman]

W, I'd suggest that you remove the clamp on the driveline cover and see if you can position it to get some grease up into the tube. You could also carefully drill it and put a grease zerk in there so you could shoot in some lube from time-to-time. If you add a zerk, do it on the side of the tube so it doesn't hang down and catch on debris.