pulling vs. carrying a load

[Diesel_Boy]

hi. i've read several posts where they say it is unhealthy for the front gears to pull a heavy load in reverse. it often times will result in a situation with a broken front gear, because they're made to pull in forward, not reverse. what about just carrying a load, instead of pulling? with 400-500 lbs IN the FEL, will that damage the front gears on say, a B3030, with any appreciable amount of backing up? thanks.

 

[RoyJackson]

If you look at the gear geometry of the front drive assist, you would see how the design is greater for a pulling load in the forward direction. This applies not just to a particular gear, but to how the gears mesh.

It's a bit tough to explain without a visual aid, so see the attachment...particularly item 14. This picture shows the front axle of a Deere 790.

The first tractor I read about (on TBN) that suffered a failure was a Deere 790. In fact, this is the only model I've read about that suffered such a failure...even then it was only one or two tractors. My dealer has never repaired such a problem.

So, we've got to make sure one or two instances (which may not have been due to the direction of load, but to a production issue) don't become "urban legends".

However, since the tractors have many more gears in the forward direction then in reverse, it seems logical that the design intent is to pull a load in the forward direction.

As far as the load in the bucket...well, you're still going forward. The load on the axle won't be on the gears, so you won't be overstressing them.

That doesn't mean you can't bust an axle by overloading the bucket...it probably won't be the gears though.

As an addendum...for those of you who leave their FEL's on all the time: Just the weigt of the loader puts more stess on the front axle, hence, increasing or accelerating wear on the components. My loader is off most of the time (well, I do leave it on during the snow season) unless I have work to do with the loader.

 

[Toolguy]

Gears and axle tend to break when they are subject to extreme loading such as "popping" the clutch or "rocking" the machine back and forth while stuck. I would think that the gradual application of load inherent to a hydrostatic drive would lessen the chances of breaking gears compared to a gear drive even in reverse. Also the extreme load placed on a MFWD axle when backing away from a dirt pile with a full bucket would soon find the weak link in the design. That is normal operation in my book and the tractor should be built to take it as I think they are. I would not be concerned with breaking anything as long as you drive with common sense. "Speed Kills" and that goes for machinery, too. Drive too fast on rough ground while carrying a full load on the FEL and all bets are off. Even then, it is nothing short of amazing how much abuse a well built machine can handle and still keep going as if nothing happened.