john deere 3020 tractor hydraulic pump

Gary Godfrey · Jun 23, 2021

Early 3020 with synchro-range trans occasionally makes hammering noise from what I believe is main hydraulic pump. Happens when warmed up and at idle speed but not consistently. Noise quits when engine speed is increased. I believe the transmission pump feeds the main hydraulics up front. Could that tranny pump be starting to fail and not get enough flow to main hydraulic pump (causing hammering noise) at idle? Anyone run into this before? Thanks

Tx Jim · Jun 24, 2021

Hyd noises can be caused by various hyd components. How long since hyd filter has been changed & hyd oil suction screen checked/cleaned?

One of the easier things to check is for wear in frt hyd pump drive coupler.

coonie minnie · Jun 24, 2021

As Jim said, look at hydraulic pump coupler first... both the two aluminum halves with the rubber bushings, and the yoke that tightens to the the pump shaft. SOmething could be loose/worn.

Gary Godfrey · Jun 24, 2021

Coupler was checked and although not taken apart to inspect it, local tractor mechanic got under and pried around finding no play.

coonie minnie · Jun 24, 2021

Good to know. I've been fooled with those already in regards to where the yoke slides on to the pump shaft. Had a couple i've made a lot of noise go away by tightening the bolt on the yoke, tightening it down to the shaft.

Gary Godfrey · Jun 24, 2021

Fresh hydraulic oil and filter within last 50 hours, but I did not remove or clean screen behind pipe plug down by the filter housing. I believe coupler good, backed by
local mechanic who checked it first thing. Maybe I should take coupler apart anyway as that seems to be the first thought of everyone. Thanks

Gary Godfrey · Jun 24, 2021

Thanks, I think I should take that coupler apart and inspect. Thanks

4520BW · Jun 24, 2021

I agree the coupler should be checked first. Broke one on the 4020 and it busted the boss on the damper and that was no fun to change.

Fritz Maurer · Jun 24, 2021

Out of curiosity, with lift arms down and engine off, if you were to start it at an idle with the lever in the raise position, would the arms raise with a jerking motion that coincided with the hammering of the pump?

Gary Godfrey · Jul 11, 2021

Gentlemen, you steered me right. The coupler when taken apart showed scuffing on both halves where one bushing was no longer cushioning between pin it rides on and the coupler. That coupler sure seemed tight before disassembled, but it must not take much wear to make that hammering noise. New coupler halves, bushings and pins put it back to normal. Thanks to you all, lesson learned.

Tx Jim · Jul 12, 2021

Thanks for posting update. Faulty frt hyd pump drive coupler bushings are a relatively simple repair.

john deere 3020 tractor hydraulic pump

Gary Godfrey

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Tx Jim

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coonie minnie

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Gary Godfrey

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coonie minnie

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Gary Godfrey

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Gary Godfrey

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4520BW

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Fritz Maurer

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Gary Godfrey

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Tx Jim

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