The REAL 7520

[NY_JD4240]

Please educate me here.
I don't know much about the 7520, it is true that you can not disengage the front axel? It just does not make sense to me that you can not disengage the front axel to go down the road. Seems like this would eat the drive train up.

 

[wore out]

(quoted from post at 06:45:52 11/30/20) Please educate me here.
I don't know much about the 7520, it is true that you can not disengage the front axel? It just does not make sense to me that you can not disengage the front axel to go down the road. Seems like this would eat the drive train up.

Yes that's TRUE, same situation with most (if not ALL) other large 4X4's (at least here in North America).

 

[Tx Jim]

My guess without researching is that the large 4 wheel drives frt & rear tires are geared to turn the same revolutions whereas MFWD tractors the frt tires are geared to turn a little faster than rear tires to help in turning corners.

 

[NY 986]

I was told quite a number of years ago that the 4wh dr tractors from that era had the front axle lead the rear axle by approximately 3 percent with a MFWD tractor at a
higher percentage. As to disengaging the front axle I don't know of any North America made 4wd from that era that can do that. The engineers most likely saw
roading the tractor as a tiny percentage of the time the tractor was in operation. Nobody envisioned running a tractor 30 miles down the road to get to a rental
property in a 20,000 acre operation or pulling manure tankers up and down the road for days on end or pulling a several hundred bushel wagon to town when the 7520
was built.

 

[Brendon-KS]

If the articulation point is midway between the two axles (as most any articulated tractor would have it) the front and rear wheels follow exactly the
same track when turning. So, there is no need to provide a disconnect since there is no tire scrubbing or driveline binding that takes place. As Wore
Out also said, no articulated 4WD tractor that I am aware of has a disconnect. It is different on a front-wheel-steered tractor (or truck/car for that
matter) where the front wheels must travel faster than the rears when turning since they scribe a larger circle.

 

[SVcummins]

It wasn’t designed by case

 

[NY_JD4240]

(quoted from post at 14:25:58 11/30/20) If the articulation point is midway between the two axles (as most any articulated tractor would have it) the front and rear wheels follow exactly the
same track when turning. So, there is no need to provide a disconnect since there is no tire scrubbing or driveline binding that takes place. As Wore
Out also said, no articulated 4WD tractor that I am aware of has a disconnect. It is different on a front-wheel-steered tractor (or truck/car for that
matter) where the front wheels must travel faster than the rears when turning since they scribe a larger circle.

Thank you. This make sense how you explained it with the center pivot being in the center. Both front and rear axels are on the same turning radius where the newer MFWD the front wheels are on a larger turning radius.