JD 4020 hydraulic pump coupler torque specs

J Key · Sep 10, 2014

Can someone advise if known what the torque is on the 4020 hydraulic pump coupler drive pins (4) and 3/8 x 2 1/2 in. bolts holding the halves together? Also the 2- 3/8x 1 1/4 in. bolts clamping the coupler to the pump shaft?
could I put longer bolts in the coupler to the pump shaft with lock nuts installed? Would that be recommended?

I was curious about the pump. The shaft has no play in it. You can turn it with you hand although not real easy. not sure if that is normal or it should turn easily with the coupler removed.

buickanddeere · Sep 10, 2014

(quoted from post at 14:39:07 09/10/14) Can someone advise if known what the torque is on the 4020 hydraulic pump coupler drive pins (4) and 3/8 x 2 1/2 in. bolts holding the halves together? Also the 2- 3/8x 1 1/4 in. bolts clamping the coupler to the pump shaft?
could I put longer bolts in the coupler to the pump shaft with lock nuts installed? Would that be recommended?

I was curious about the pump. The shaft has no play in it. You can turn it with you hand although not real easy. not sure if that is normal or it should turn easily with the coupler removed.

The pump is a variable displacement eight piston closed Center pump.
What grade of bolt and fine or coarse thread ? Dry or oiled ?
For dry threads on a plain 3/8 bolt . The torque depending in the grade of fastener could be 13,20,31,38 or 44ft lb.

Tx Jim · Sep 10, 2014

(quoted from post at 14:39:07 09/10/14)
could I put longer bolts in the coupler to the pump shaft with lock nuts installed? Would that be recommended?

I was curious about the pump. The shaft has no play in it. You can turn it with you hand although not real easy.

I don't know the correct bolt torques but you can put longer bolts with nuts in the 2 halves. Hyd pump should be fine.

tim s · Sep 10, 2014

Bolts are special, a regular bolt won't thread through all the way, it bottoms out on the thread before it gets tight...you can re-thread a bit more on a regular bolt to make it work..

D- · Sep 10, 2014

Regardless of the torqe you should use medium (blue) loctite on the studs and bolts at splined end of shaft.
The clamp bolts should have locknuts on them.
Hard to turn is normal.
For b&d all are course threads.

Mike M · Sep 10, 2014

I can't remember if the book gives torque specs. on those or not ? On bolts not listed in the book I would use a common bolt torque chart and go by the bolt size and thread pitch and grade marking on the top.
Google should bring up a chart.

J Key · Sep 10, 2014

thanks for the quick info. I am using grade 8 bolts and was planning on blue lock tite. I did cut the threads on the 2 1/2 in bolts a little deeper this morning so they would bottom out, then will apply lock nuts on the end for the two clamp halves.
one of the drive pins had broke off causing the coupler to finally break. replacing all parts with new. Biggest job was getting the big gash in the bottom of a one year old radiator repaired. Looks like we are on track. thanks again

ET · Sep 10, 2014

Deere says 35ft lbs on those.

Bob · Sep 10, 2014

Here's the correct bolts for the coupler...
19H2116 $1.30 each

Specification
Weight: 0.09 LBS 0.04 Kg
Diameter 0.375 IN
Thread UNC2A
Length 2.500 IN
Thread Length 2.344 IN
Width Across Flats 0.562 IN
Head Height 0.243 IN
Material Grade A17D

The locknuts are #E50102 at less than a buck.

buickanddeere · Sep 10, 2014

(quoted from post at 20:54:37 09/10/14) Here's the correct bolts for the coupler...
19H2116 $1.30 each

Specification
Weight: 0.09 LBS 0.04 Kg
Diameter 0.375 IN
Thread UNC2A
Length 2.500 IN
Thread Length 2.344 IN
Width Across Flats 0.562 IN
Head Height 0.243 IN
Material Grade A17D

The locknuts are #E50102 at less than a buck.

To think about all those owners who re-used the bolts as new were "too expensive ".

Tech 7 · Sep 11, 2014

IIRC for the clamping bolts you are to install the bolts and torque them to 35 ft/lb then while preventing the bolts from turning install the locknuts and torque them to 35 ft/lbs.

jrsavoie · Nov 9, 2018

The correct torque for the 2 bolts that hold the yoke on is 35 ft lbs.

The bolts and nuts through the aluminum clamp are 20 ft lbs. You torque the bolts first, be sure to hold the bolt heads and tighten the lock nuts.

I put a center bolt in while assembling. Just seems to make it easier since I can't hardly get my hands in there. I just snug the nut up and that lines things up and makes the threaded bolts much easier to start.

Don't forget to remove the center bolt.

JD 4020 hydraulic pump coupler torque specs

J Key

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buickanddeere

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Tx Jim

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tim s

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D-

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Mike M

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J Key

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ET

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Bob

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buickanddeere

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Tech 7

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jrsavoie

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