
Your Auto Crane NexStar hydraulic system is down — the pump motor has failed, it's running slow, drawing excessive current, or the brushes are burnt out. The dealer wants $1,052+ for a replacement motor. That's over a thousand dollars for a standard wound field DC motor. Your service truck is sitting on a job site with a fully functional crane that has no hydraulic power. Every hour it sits is money lost.
We sell the direct replacement hydraulic pump motor for $489 — saving you over $500 vs the dealer. This is the same specification motor: 12 Volt DC, 4.5-inch wound field, slotted (tang) shaft, CCW rotation. It bolts directly onto the hydraulic power unit on your Auto Crane NexStar 3203EH or 4004EH. Replaces Auto Crane part number 320991271.
Auto Crane NexStar power units come in two electrical configurations:
How to check: Look at the end cap (rear) of your existing pump motor. Count the terminals (posts). If there is one post, this is the correct motor. If there are two posts, contact us — you need the isolated ground version.
The hydraulic pump motor on the NexStar power unit is the heart of the entire crane system. When it fails, you lose all hydraulic functions — boom, outriggers, rotation, everything. The motor runs hot, the brushes wear out, and eventually the armature burns up or the field windings short. The dealer replacement is $1,052 — an absurd price for a standard wound field DC motor. And the lead time from the dealer can stretch to weeks, leaving your truck and crane completely out of service.
This is the same specification wound field DC motor sized for the Auto Crane NexStar hydraulic power unit. Same 4.5-inch frame, same slotted (tang) shaft that interfaces directly with the hydraulic pump gear, same CCW rotation, same 2-bolt thru-bolt flange mounting pattern. It is a direct bolt-on replacement — remove the old motor, bolt on the new one, reconnect the power cable, and you're back in service.
The 320991271 hydraulic pump motor fits the following Auto Crane NexStar models:
⚠️ Verify your terminal configuration (1-post vs 2-post) before ordering. Also verify Auto Crane part number 320991271 in your service manual or on the data plate of your existing motor. Some older NexStar units may use a different motor specification — contact us with your crane model, serial number, and terminal count to confirm fitment.
How do I know if I need the 1-terminal or 2-terminal version?
Look at the rear end cap of your existing motor. If there is one power post (stud), you have the standard case ground motor — this listing is the correct one. If there are two power posts, you have the isolated ground version and need a different motor. Contact us with your crane model and serial number if you're unsure — we'll confirm which version you need.
Why is this so much cheaper than the dealer?
The dealer price of $1,052 includes significant markup on a standard wound field DC motor. This motor is built to the same specification — same voltage, same frame size, same shaft type, same rotation, same mounting pattern. We source it at a fraction of the dealer cost and pass the savings to you.
Is this motor as good as the one the dealer sells?
Yes. This is the same specification heavy-duty wound field motor. Same 4.5-inch frame, same slotted shaft, same CCW rotation. It is built for continuous-duty hydraulic pump applications and uses heavy-duty brushes designed for extended service life.
Will this work with my NexStar computer controls?
Yes, as long as you have the correct terminal configuration. The 1-terminal (case ground) version is compatible with standard NexStar systems. If your NexStar has advanced electronic controls that require an isolated ground motor (2-terminal), contact us for the correct version. Using a case ground motor on an isolated ground system can damage the electronic controller.
How long does installation take?
About 30–45 minutes for a qualified mechanic. The motor is secured by two thru-bolt flange bolts and one or two power cables. It slides straight out and the new one slides straight in. No special tools required — standard wrenches and sockets.
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Direct replacement 12V DC hydraulic pump motor for Auto Crane NexStar 3203EH and 4004EH power units. 4.5-inch wound field motor, slotted (tang) shaft, CCW rotation. 1-Terminal (case ground) configuration. Save over $500 vs dealer pricing. Verify terminal count before ordering — some NexStar units use 2-terminal isolated ground.
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