+$200 Core Exchange Charge
Part# 07-06410
MFR Model# ALX-9525BR
Hartzell Part No.Volt/AmpDriveReplacesPN
ALX-9525BR12V/70ADirectCMI 643008 07-06410


We carry the full line of alternators, generators, and starters which are re-manufactured by Hartzell Engine Tech for installation in general aviation aircraft.

Prestolite series alternators see widespread use on OEM applications. This aircraft alternator line was originally developed by Prestolite, but the designs have continued to be refined and improved by Hartzell.

Fully FAA approved. All prices shown are exchange prices. Core charges are billed when unit is shipped. Core credit is issued upon return of acceptable like model core to us.

Attention: These charts are for reference only. Check owners manual or current part installed to verify the model required prior to puchase. NOTE: If core is not in stock at factory, customer must send core to us at time of order to have the core overhauled.

Core Return Policy:

Any unit being returned for core or warranty core credit shall be, as removed from the engine, complete and not disassembled. No core or warranty core credit will be allowed for automotive units. Units that are rusty or cannot be overhauled for any reason will be classified as scrap, having no value. Units which have been weld repaired, as well as units which have been disassembled and then reassembled with old parts, will also be classified as scrap, having no value. A percentage of the core value will be charged for all missing or damaged parts. At no time will the damaged or missing parts charge on any unit exceed the core value of that unit.

1. Core will only be accepted for credit 12 months from date of invoice.
2. Cores returned in excess of cores invoiced will not be accepted.
3. Cores must be of like purchase, a directly superseded unit or replaced unit when installing an STC'd product.
4. Competitive product cores are acceptable returns.
5. Cores must have a legible data tag for part and serial number verification.

Note: Customer will need to provide core for overhaul in the event our supplier does not have cores available to overhaul.

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Alternator came complete with cooling shroud and pully ready to install. Worked perfectly and got the aircraft back in the air.

July 27, 2020

The garlock seal is in the unit, but it does not come with a gasket, that would have been important to state. Why are accessories sold without gaskets? Absurd.

Burbank A
April 9, 2020

Good price for the alternator and fast ship. It should state the oil seal part number and the fact that it’s not included with the alternator. I understand it’s considered part of the coupling, but a new one is needed to replace the alternator. This is really important for AOG part 135 aircraft.

Eastwest A
February 3, 2019

The rebuilt unit does not come with the Garlock seal. Would be nice to know for AOG situations. [ALX-9525BR]

September 20, 2016


Please note, Aircraft Spruce's personnel are not certified aircraft mechanics and can only provide general support and ideas, which should not be relied upon or implemented in lieu of consulting an A&P or other qualified technician. Aircraft Spruce assumes no responsibility or liability for any issue or problem which may arise from any repair, modification or other work done from this knowledge base. Any product eligibility information provided here is based on general application guides and we recommend always referring to your specific aircraft parts manual, the parts manufacturer or consulting with a qualified mechanic.

Q: Is the ALU-8521 (08-07127) unit 70A?

Yes, part number 08-07127 is 24V / 70A.

Q: Do I understand right that ALU-8521 is a new alternator, not overhauled (and ALU-8521R is the overhauled one)? If we buy new alternator, will we pay an additional core price? If yes, how much?

Yes, that is correct. ALU-8521 is a new alternator and ALU-8521R is the overhauled version. If you buy a new alternator, there will be no additional core charge added to the order. The core program is only valid for purchases of overhauled alternators.

Q: I want to purchase an ALY-8520R alternator which supercedes my old unit which is ALY-8403. Is this acceptable for a core exchange?

Yes, this is an acceptable core.

Q: Does the ALY-8520R alternator come with a pulley and cooling fins?

Yes, this will come with the pully and cooling fan.

Q: Does the ALY-8520R have built-in over voltage protection?

No, the ALY-8520R does not incorporate internal regulation of any kind.

Q: Does the ALY-8520 come with the pulley?

Yes, it does.

Q: Is a Prestolite ALY-8420R an acceptable core exchange for an ALY-8520R? Additionally, is the 8520 as delivered a direct replacement for the 8420?

Yes that should be an acceptable core and 8520 superseded the 8420.

Q: I receive an alternator but it doesnt come with pulley. Can i know what part no. Does the pulleys of aly 6521r alternator? Thank you.

The pulley part number is 07-03391.

Q: What is the difference between an ALT-8520R and an ALT-8521R? Also the photos of both show a blast tube coming out out of the side of the alternator. The blast tubes come out of the back on the ALT-8520R and ALT-8521R not the side. The only difference we can see the direction the tube points.

The ALT-8520 is approved for TCM and ALT-8521 is approved for Lycoming.

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