4840 JD Tractor

Can anyone give me an idea what could be the problem?
Driving 4840 all of a sudden it stops, runs but won't move forward or backward, no steering, have brakes but no pto or hydraulics.
Is this the transmission?
Any idea greatly appreciated.
Thanks

POSSIBLY the "torsional damper" at the engine flywheel has failed, or it's splines and/or those of the transmission input shaft have failed.

I agree with Bob about the pump drive, could be the suction screen plugged but it should not have stop it that fast.

(reply to post at 12:43:42 04/07/17)

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Possibly the transmission oil pump drive shaft ? This info is for the quad range.

http://jdpc.deere.com/jdpc/servlet/com.deere.u90490.partscatalog.view.servlets.HomePageServlet_Alt

http://jdpc.deere.com/pimages/RXP7/RXP7791________UN01JAN94.gif
TRANSMISSION OIL PUMP
(QUAD-RANGE)
Cart KEY PART NO. PART NAME QTY TRACTOR SERIAL NO. 4640 4840 REMARKS
1 AR79836 OIL LINE 1 X
2 R82161 MANIFOLD 1 X (SUB FOR R63998)
3 AR78652 GEAR 1 X (SUB AR78649) (ALSO ORDER RE20919)
4 AR78653 GEAR 1 X (SUB AR78649) (ALSO ORDER RE20919)
5 R51029 DOWEL PIN 1 X
6 RE20919 HOUSING 1 X (SUB FOR AR85539) (MARKED R63997 OR R82164) (ALSO ORDER AR78649)
7 A3606R O-RING 1 X
8 R64406 OIL LINE 1 X
9 A3917R O-RING 1 X
10 AR71016 OIL LINE 1 X
Cart KEY PART NO. PART NAME QTY TRACTOR SERIAL NO. 4640 4840 REMARKS
11 R40147 FITTING 1 X
12 A4808R WASHER 1 X
13 R53169 SCREEN 1 X (NYLON)
AR26375 SCREEN 1 X (STEEL)
14 R41008 CAP SCREW 2 X
15 R67247 BOLT 2 X (SUB FOR R64401)
16 R27218 FITTING PLUG 1 X
17 R26448 O-RING 1 X
18 R26372 SPRING 1 X
19 R42849 BALL 1 X 9MM (3/8")
Cart KEY PART NO. PART NAME QTY TRACTOR SERIAL NO. 4640 4840 REMARKS
20 R56462 O-RING 2 X (SUB FOR B2762R, THIS APPLICATION)
21 R66049 PIN FASTENER 1 X
22 F3171R O-RING 1 X
23 AR72101 FITTING PLUG 1 X
24 R41168 CAP SCREW 1 X
25 R51383 SELF-LOCKING SCREW 1 X
26 15H558 PIPE PLUG 1 X 1/8"
27 R41008 CAP SCREW 1 X (SUB FOR R43252)
28 R64407 OIL TUBE 1 X
29 R41041 CAP SCREW 1 X
Cart KEY PART NO. PART NAME QTY TRACTOR SERIAL NO. 4640 4840 REMARKS
30 24H1653 WASHER 1 X 13/32" X 1-1/4" X 0.120"
31 R48792 WASHER 1 X
32 R66061 HALF CLAMP 1 X
33 19H2284 CAP SCREW 1 X 3/8" X 7/8"
34 R30959 LOCK PLATE 1 X
35 T13814 CLAMP 1 X

4840's only came with 8spd power shift...

(quoted from post at 18:08:36 04/07/17) 4840's only came with 8spd power shift...

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TimS you are correct , my error. I should have noticed the same parts book lists the Quad or PS 4640 along with the PS only 4840.

Oh yes..you got to be sure your on the right line...

Years ago[35] we had a new 4840 and it did basically the same thing.It was the brake linings and they evidently had linings that came apart plugging all the hydraulics.Had to be completely cleaned out ,new linings installed and still going strong.It was under warranty but it is quite a job as they were everywhere.I just heard of an 8370R that had brake problems of same nature don't know details.With the IVT the brakes get a lot of use on a grain cart.

With the IVT the brakes get a lot of use on a grain cart.

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Never understood why in the US they do not put the hydraulic trailer brakes commended by the tractor. Does not make any sense to pull a 500BU grain cart without brakes, yet a 1300 bu one.

I bought a 4840 that supposedly the trasmission was bad but we noticed it had no hydraulics. Split it open to find a broken dampener. So I would say if it does have hydraulics, then that is not your problem.