Farmtrac 785- Front & Rear Mechanical Differential Lock

[Slacker]

The Farmtrac 785 4wd states Front & Rear Mechanical Differential Lock as a feature. Can anyone explain to me how it works? Does it actually give true 4WD? Is this a common feature on tractors this size? (85hp)

 

[daTeacha]

A differential lock makes both wheels turn at the same speed. Normally, driving wheels are designed to run at differing speeds to allow for turning. Most tractors that I am familiar with allow the operator to lock the rear differential by stepping on a pedal. This helps prevent getting stuck now and then. The articulated machines can make a front diff lock work, but I've never seen one on a conventional tractor -- I think there would be too many torn up front drive units.

 

[schmism]

i thought ive read that some of the smaller AG tractors have an optional front diff lock.

it can be key for keeping the tractor pulling in a slightly wet feild in a straight line.

With the diffs locked the machine will NOT want to turn and you WILL get a lot of wheel scrub when TRYING to turn.

 

[Rara Avis]

You don't need them when you use JD's Greenstar for field positioning...
The GreenStar™ Family of Products

 

[redlevel]

You don't need them when you use JD's Greenstar for field positioning...
The GreenStar™ Family of Products

Am I missing something obvious? I don't see how this feature would negate the need for limited slip or locking diffs.

If I am not badly mistaken, I believe the Kubota M6800 I had for a while had diff lock pedals for both front and rear axles. I could be wrong, though.

My Farmtrac 535 has the pedal for locking the diff, but I have discovered that the differential automatically locks when one wheel starts slipping. None of the other utility tractors I have owned did that. It is very convenient.