Tree Farmer C4D Forwarder Tranny

[Corley5]

  The four speed tranny in my forwarder began making noise in 1st gear today.  The noise is loudest in 1st but is faint in neutral.  It's a "light" intermittent grinding noise not like you'd hear if you tried shifting without clutching.  It sounds almost like a gear is bouncing off another or something else  :-\ ???  There's no movement in the shift lever when it's making the noise.   First still works fine, doesn't jump out of gear etc.  Would a bad synchronizer do that?  It shifts into 1st fine with no grinding or force required.   2nd and 4th work fine.  3rd doesn't, it's been "lost" for a while now.  It worked fine but it got so you had to hunt to find it.  Put it in the other gears a couple times to get things lined up just right before it would go in then it got to the point that didn't work.  I think that's wear in the shift forks.  Never used third much anyway  ;)   I sure don't want to pull the transmission but that's where I think this is headed :-\  We're almost done with this job.  The cutter has about a days's worth of work left and there'll be 75-100 cords of pulp and few sawlogs to gather up.  Wish it would have waited a couple weeks  ;D  

[bushmechanic]

Did you chech the obvious-oil level?A noise in first gear will be in the rear of the gearbox most likely a bad bearing or a tooth gone from either the gear or the bottom shaft.Check the output bearing by grabbing the rear yoke and moving it up and down.Also check the rear yoke it my be stripping out on the spline.Too bad it had to happen with all that wood on the ground.

[Corley5]

We're going to look at it closer in a little bit.  It was late in the day yesterday    The fluid level hasn't been checked in a while but there haven't been any signs of leaks either.  That's the first thing on the list to check 

[Corley5]

  The grease was low but it wasn't dry.  Drained what was in it and flushed it with fuel oil.  Not much in the way of metal came out.  Filled it up with 80-90 and the noise is gone  :-\  Ran it around the landing a bit and all seems well.  The noise is gone  :-\  It's still a concern.  I've never had anything that started making sounds it shouldn't last long    Also replaced the alternator belt, cleaned the cooling air intake screen, greased and checked the rest of the fluids.  I don't see any obvious leaks from the tranny  :-\ but it's going somewhere.
  Going to bale hay now.  Enough skidder fun for the day  ;D

[bushmechanic]

You would be suprised how long that gearbox will last.The trouble with a forwarder is that unlike a skidder when you are stopped loading the gearbox rpm is up so you can use the loader and low oil level translates into more heat.Also if I think correctly your gearbox is a New Process 442 then there is no seal on the input shaft just a worm seal so you may get some seepage into the bell housing.You had better get cracking on that wood!