Frequently Asked Questions

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Do I need to fill out a work order?

Yes. All work must include a work order form. Go to the New Work Order Form or the Remanufacture Work Order Form page and complete the form online, print it and include with your parts. We ask that you fill these forms out prior to sending in your part so that we have all instructions and contact info handy. If you prefer, you can print out a hard copy of the forms and complete them by hand by clicking on the Remanufacture Work Order Form(PDF), or the New Work Order Form (PDF). 

Do you line-lap Evolution cases?

Yes. Your pinion shaft bearing race MUST be used for proper fitment. We will not be responsible for improper fitment if our machinists are unable to measure your pinion race. When pinion races do not meet our specs, have the pinion replacement serviced and toleranced checked and proper bearings fitted. 

What guidelines do you use to bore cases?

Darkhorse Motor Companys bore cases according to cylinder manufacturer's tolerances which vary. We have specific processes for each manufacturer and may choose to position center case bolt as a "through bolt "versus a "tapped blind hole" for added structural integrity. You may receive top center case bolt with cases that are integrated to that specific bore and case. The positioning of this bolt is critical and must align with case opening so it does not distort cylinders upon installation. Weeping at center case bolt may occur if not sealed properly. We recommend a semi-drying liquid gasket and a clean surface behind the sealing washers of case bolt supplied to deter any weeping from occurring on either side. 

What specifications does Darkhorse follow?

We blueprint all crankcase and crankshaft work to meet or exceed OEM specifications. 

What guidelines do you use to install crankshafts?

Our crankshafts will install as any stock flywheel per the manufacturer's recommendations. We hold strict tolerances according to or exceeding manufacturer's recommendations and ask that you do the same. 

Where do you measure crankshaft total indicated run-out?

Our stance on this issue has not changed or wavered since 1980.  The most important unit of measurement is at each main bearing race with a crankshaft orientated on proper shaft centers. Our warranty is based off this measurement - without exception. 

Do you work on motorcycle heads or cylinders?

No, we do not. We do work for almost all the top builders around the world. We would not think of competing against them. This is why they trust us and recommend our services in return. 

What cam or heads should I run with my engine?

We do not get involved with cam or head decisions. Please consult with your chosen engine builder or top-end professional. 

Can you recommend an engine builder?

We work for many throughout the USA and would find it difficult to recommend one over another. Review our dealer locator map to locate a dealer near you that listens to what you want and one that you feel confident will get the performance and output YOU require. 

Can I speak directly with a technician?

Yes. You may contact a technician to answer any question regarding our work or process between 9:00 AM - 5:00 PM CST Monday through Friday. 

I have a question on the assembly procedures. What do I do?

Refer to the factory service manual for information on assembly procedures or feel free to call us between 9:00 AM - 5:00 PM CST Monday through Friday.  

How long will you store a crankshaft without a work order

Crankshafts designated by supplier without a clear direction of work to be done, will be considered abandoned after 12 months. All associated parts will become property of Darkhorse Motor Company.   

How do I assemble my Timken® bearing conversion crankcase?

For any questions or concerns regarding one of our Timken bearing conversion cases in late model Twin Cam applications, please refer to Harley Davidson 1999' or 2000' FLT service and parts manual for FLHT, FLT and FLHR models, 99' or 00' Dyna service and parts manual for any Dyna series and 2000' service or parts manual only for Softail series bikes. Or, you can contact us directly from 9:00 AM - 5:00 PM CST Monday through Friday

Can I interchange INA spacers for Timken?

No! You CANNOT interchange INA® bearing sprocket shaft spacers for Timken-style bearing spacer. This will cause damage to primary components and may cause injury or death. We will supply the corresponding correct sprocket shaft spacer unless notified at time of shipping. 

What is the Timken end-play set at?

We install races and preset Timken bearing end-play between .001” - .003”. You must check this measurement upon final installation into case and make sure they are within factory specs of .001” - .005” This is very critical to the longevity of your motor and related parts. 

Must I send in both case halves for a Timken bearing upgrade?

Yes. We first verify that case halves are concentric to < .001”  before we install our conversion insert.  This is critical to the longevity of the entire motor. When we verify main bearing bore alignment, we will also cut a groove to retain the pinion bearing in the right side case half. 

How do I get a dealer discount?

To receive a dealer discount, a Dealer Application must be approved and on file upon completion of work. Our procedures do not include part costs. Please do not assume it will be all-inclusive. We work on brand new to very old crankshafts and cases. It would be impossible for us to have set flat rates for our procedures. Contact us if you need a quote prior to beginning work. 

What dealers do you recommend?

We work for many throughout the USA and would find it difficult to recommend one over another. Review our dealer locator map to locate a dealer near you that listens to what you want, and one that you will get the performance and output YOU require. 

I work out of my garage part time. Can I be a Darkhorse Crankworks dealer?

No. We require all dealers to be full-time dealers who work on Harley Davidson motorcycles as their primary source of income. We understand there are many great mechanics who work on the side. However, we must protect our dealers and their ability to make a fair living representing and focused on our product.  You can purchase our product at retail prices through us. We encourage everyone to support our dealer network as their first choice. 

What is your warranty?

The Darkhorse Limited Warranty covers all street versions of our crankshafts and casework including remanufactured components. The 2 year/unlimited mileage warranty protects you against workmanship defect. We true all crankshafts to within .0015” total indicated run-out at each main bearing race and guarantee all street/OEM applications to stay within  .0005” for 2 years and unlimited miles. See warranty page*

Do you insure parts that are shipped?

We will insure the package for estimated value of product plus services. If something exceeds normal value, you must document the need for added insurance value on the work order. 

Are you responsible for damages?

Darkhorse Motor Company shall not, under any circumstances, be held liable for consequential damages, including parts not sold by Darkhorse Motor Company, labor not performed by Darkhorse Motor Company, or loss of profits.  Installation of any aftermarket part, including parts and services by Darkhorse Motor Company, may adversely effect the OEM vehicle warranty. 

How are packages shipped?

All packages are shipped UPS regular ground unless requested and stated. Prices do NOT include return shipping. 

How do I ship a crankshaft and/or entire lower end?

If you are uncomfortable with your box building capabilities, please call our sales department and they can send you a boxing system that will give as much safety as possible in getting to our facility!  Just call 920.726.9999 for details.
Crankshafts that are not captured, have a tendency to rock back and forth during shipment and damage associated parts.  Please lock-down crankshaft and cases from any movement. Double walled corrugated cardboard boxes should be used at a minimum for shipping. We recommend you include a base of wood or extra cardboard to support product. Heavy paper or cardboard must be used in direct contact with engine parts. Packing peanuts or bubble wrap are not satisfactory packing materials for heavyweight crankcases or crankshafts.  Please package accordingly when shipping product to us, and we will package with that same expectation in return to you. We will insure product in return shipping for our estimated cost for product replacement (including our services). We recommend you insure the product too. We will not be held responsible for any shipping damage.