PRO Program members can receive tiered savings on this line—up to 20% more off for qualifying accounts.
Shipping estimate & delivery timing
Share this product on social media and get an exclusive discount code!
Click any platform below to share this product. After sharing, you'll receive a discount code!
Built to support repair shops, fleets, and equipment owners with dependable parts sourcing and responsive service.
Qualifying new parts include 1-year coverage. Review the Warranty Policy section for coverage details, claim steps, and exclusions.
Eligible orders may qualify for returns within 90 days. See the Easy Return Policy section for conditions and next steps.
Send a question through Ask a Product Question or the contact form. Our team reviews requests on business days and follows up as quickly as possible.
Flywheel 3999603 for Cummins Engine ISDE ISBE QSB 4B 4BT 4BTA 6B 6BT 6BTA 5.9
Replace Part Number:?3999603, C3999603
Fit for Engine:?Cummins ISDE, ISBE, QSB, 4B, 4BT, 4BTA, 6B, 6BT, 6BTA, 5.9
| original | 3999603, C3999603 |
Official answers about compatibility, package contents, specifications, installation, shipping, and warranty for Flywheel 3999603 for Cummins Engine ISDE ISBE QSB 4B 4BT 4BTA 6B 6BT 6BTA 5.9 (SKU: ES13029).
No product questions yet. Ask us using the product question form.
Send us your product question and we'll reply by email.
Every new aftermarket part from us includes a 1-year warranty. Full terms, coverage, and how to make a claim: Warranty Assistance.
We ship to customers around the world. Orders are sent with our standard courier service—trackable, dependable, and easy to work with. On this product page, use Get Estimate under the price to see shipping cost and estimated delivery for your location. For destinations, rules, and full details, read our Shipping Policy Details.
We want you to be confident in your order. If you are not satisfied, you may qualify for a return or refund within 90 days, subject to conditions. See our Easy Return Policy for eligibility, steps, and exceptions.
