How Can We Help?

Answers to the questions we hear most — ordering, shipping, cores, fitment and warranty. Can't find it? A real diesel tech is one call or text away.

Need help matching a part? See what to send us.

Ordering & Payment

Use our OEM Cross-Reference tool — enter the number stamped on the part or box to look for a reference match. Confirm the application details before ordering. If it doesn't return an instant match, call or text (720) 445-6249 and a specialist will cross it by hand.

All major credit cards, plus Shop Pay, Apple Pay and Google Pay at checkout. Approved trade/fleet accounts can buy on net terms — ask about opening a fleet account for volume pricing.

Yes. Shops and fleets get dedicated pricing and a direct line to a specialist. Contact us to set up an account.

Yes — pay monthly with Shop Pay Installments on eligible orders. The available options show on the product page and at checkout.

Shipping & Delivery

Dispatch and delivery timing vary by item and destination. Send the part number, quantity, delivery ZIP code and when you need it so we can check available options. Full details on our Shipping Policy page.

Eligible orders of $1,000 or more shipping to the lower 48 get free standard ground freight, applied automatically at checkout. Expedited and air upgrades are billed at cost.

Sign in and open Track Order to see live status and carrier tracking for every order. You'll also get a tracking email as soon as it ships.

Note the damage on the delivery receipt before signing, photograph it, and report it within 5 business days. We file the carrier claim and ship a replacement — see Shipping Damage & Claims.

Cores & Returns

A refundable deposit on parts built around a rebuildable core. Core-return deadlines vary by product and are confirmed before purchase. Follow the deadline and return instructions provided for your order. A refund depends on the core meeting the applicable condition requirements. Details on our Core Charge Policy.

Most new, uninstalled parts can be returned within 30 days with an RMA. Call or text us for an RMA number, then ship it back. See the full Returns & Refund Policy.

Built-to-order heads (Stage 3 / Stage 6) are non-returnable once machining starts, and warranty claims are subject to the applicable coverage terms. Not sure which stage fits? Call a builder first.

Fitment & Compatibility

The Cross-Reference tool lists selected part-number references; a reference match alone does not establish exact fitment. For a final check, text a photo of your part tag to (720) 445-6249 and we'll confirm fitment by hand. Engine serial number (ESN) matters on kits and heads.

We cover Caterpillar, Cummins, Detroit, Mack/Volvo, Paccar and International. Shop by engine or cross a number to confirm.

Warranty & Support

PAI Industries parts carry a 2-year, unlimited-mileage warranty (3 years on the High-Performance tier). JAK'S Diesel cylinder heads carry a one-year, parts-only warranty from the invoice date. Labor and warranty shipping costs are excluded. Full terms are on the Warranty & Returns page.

Call or text (720) 445-6249 with the part or serial number. We work the claim with the manufacturer for you — we will explain the next steps for your claim.

Always. You're talking to experienced diesel techs, not order-takers — before and after you buy. Contact us. Customer-service hours: Monday–Friday, 7:00 AM–6:00 PM MST.

No articles match that search. Try a different term — or call a specialist at (720) 445-6249.

What to send when you need help matching a diesel part

A useful parts request starts with the engine and the number on the part you are replacing. Sending both helps separate similar-looking options before you order.

1. Start with the numbers you have

Send the manufacturer or replacement part number exactly as it appears, including letters and dashes. If you have more than one number, identify where each came from: the old part, a box, an invoice or a supplier listing. A clear photo helps us check what you are reading.

2. Include the engine information

Provide the engine make, model and serial number if available. The truck model or a broad engine name can be a starting point, but it does not establish that every part listed for that family fits your engine. If you do not have the serial number, send the information and photos you do have.

3. Tell us what you need in the order

Include the quantity and whether you are replacing one component or looking for a kit. Check whether the listing is for an individual piece, a multipack or a kit. For kits, ask about the exact included components rather than assuming everything shown in a related listing is included.

4. Add your delivery ZIP code and timing

Your destination and required date help us check shipping options. For larger shipments, tell us whether the delivery location has a loading dock or forklift and whether it is residential. Available dispatch and delivery options depend on the item and destination.

5. Check core terms where a core charge applies

Core-return deadlines vary by product and are confirmed before purchase. Keep the return instructions supplied with your order, and contact us with your order number before sending a core back.

A quick message you can copy

I’m looking for [part number or description] for a [engine make/model]. Engine serial number: [if available]. Quantity: [number]. Deliver to ZIP [ZIP]. Needed by [date]. I’ve attached a photo of the part number or tag. Please help me check the match and available shipping options.

Email parts@jaksdiesel.com or call or text (720) 445-6249. If you already know the part you need, you can browse our parts collections and use the optional fitment-verification choice when available.

Customer-service hours: Monday–Friday, 7:00 AM–6:00 PM MST.

Request help matching a part

Still Need A Hand?

Talk to a real diesel specialist — no call-center runaround, no scripts.