By Michael Nielsen, Publisher | 15+ Years in Diesel Repair
Last Updated: October 2026
Shortages and lead times for heavy-duty parts look different in October 2026 than they did from 2021 through 2025. The evidence points to a problem that is now more about price and predictability than empty shelves, and that still needs a plan.
This Heavy Duty Journal guide covers what the data shows, how tariffs affect parts, how to measure your own lead times, and a response plan for late parts. It replaces unsourced lead-time tables and downtime figures from an earlier version with named sources and examples labeled as examples.
Key Takeaways
- ✓Price now matters as much as supply. TMC fleet members ranked cost containment first in Spring 2026, and parts availability did not make the top five in either 2025 or 2026 surveys.
- ✓A 25% Section 232 duty applies to listed imported parts. Proclamation 10984 took effect November 1, 2025, with USMCA treatment for qualifying parts handled separately.
- ✓Quoted lead times are not planning numbers. Log promised and actual dates, then plan around the actual ones.
- ✓Protect only the parts that stop a truck. Compare a downtime day to the carrying cost of a part before you stock it.
- ✓Set up the second supplier before you need it. Accounts, cross-references, and written escalation contacts save days.
In This Guide
- Shortages and Lead Times: Where Things Stand in October 2026
- What Is Driving Parts Cost and Availability Risk Now
- Deciding Which Parts Deserve Protection
- Measure Your Own Lead Times
- Diversifying Suppliers and Substitutes
- Supplier Terms and Communication
- Using Maintenance Planning to Buy Time
- What to Do When a Critical Part Is Late
- Frequently Asked Questions
- The Bottom Line
Shortages and Lead Times: Where Things Stand in October 2026
Start with what fleets themselves report. TMC's Spring 2025 survey listed Parts Shortage/Availability among concerns that tied for sixth, just outside the top five. See the Spring 2025 results. In Spring 2026, more than 400 fleet members ranked cost containment first and inflation in parts, oil, fuel, and equipment third. See the Spring 2026 results.
Cost data tells a similar story. As of October 2026, the latest Decisiv/TMC benchmark I could find shows combined parts and labor costs fell 3.0 percent quarter over quarter in Q1 2026, with parts down 4.6 percent and labor down 0.6 percent. Year over year, combined costs were down 0.8 percent. See the TMC benchmark release.
25%
Section 232 duty on imported medium- and heavy-duty trucks and listed parts, effective November 1, 2025, under Proclamation 10984.
Do not read that as the end of the problem. Costs fell in 15 of the 25 VMRS systems tracked, but year-over-year costs were still higher in 18 systems. ATRI reported that repair and maintenance costs rose 8.6 percent in 2025 and that average truck age and annual mileage increased. See the ATRI release. Older trucks run more miles and need more parts.
What Is Driving Parts Cost and Availability Risk Now
The main new factor is trade policy. Proclamation 10984, signed October 17, 2025, imposes a 25 percent ad valorem duty on imported medium- and heavy-duty vehicles and the parts listed in its Annex I, effective for goods entered on or after November 1, 2025. See the proclamation text.
The text has parts-specific details. Imported parts that qualify for USMCA preferential treatment are not subject to the added duty until Commerce, working with CBP, establishes a process to apply it to the non-U.S. content and publishes a notice. The Secretary can also add parts to the covered list. A February 2, 2026 Federal Register notice set documentation procedures for importers of vehicles. See the notice.
For a fleet or shop, the practical questions are simple. Ask suppliers where a part is made, whether it qualifies under USMCA, and how long a quoted price is good for. Because the rules can change, confirm current duty treatment with your supplier or a customs broker before you rely on any pricing.
Labor adds to the squeeze. TMC's Spring 2026 survey ranked technician shortage second and technician staffing fifth, so even when a part arrives, a short-staffed shop may take longer to fit it.
Deciding Which Parts Deserve Protection
You cannot stock everything, so decide what to protect. Sort parts by what happens if one is missing. A part that stops the truck, has one source, or has a long quoted lead time deserves attention. A commodity item does not. HDJ's reorder point and safety stock guide covers the calculations.
| Tier | Typical parts | Response |
|---|---|---|
| 1: Stops the truck | Electronic control modules, aftertreatment components, major assemblies, parts with one source or long quoted lead times | Hold stock or a pre-arranged alternate, and review lead times monthly |
| 2: Common failures, several sources | Brake components, belts, hoses, sensors, wear items | Min-max stock and two approved suppliers |
| 3: Commodity items | Fasteners, filters, fluids, common hardware | Reorder on usage and keep it simple |
Test each stocking decision against downtime. Daily downtime cost is the revenue lost that day, plus idle driver cost, plus any tow or rental cost. Compare that with the cost of carrying the part, which includes the capital tied up, storage, and the risk it never gets used.
Here is an example with assumed numbers. A truck earns $900 a day, a part costs $1,200, and carrying cost is assumed at 20% a year, or $240. One avoided downtime day is worth $900, which exceeds a year of carrying that part. Use your own numbers, and avoid stocking parts that fit only one retiring unit or one customer.
Measure Your Own Lead Times
Supplier quotes are promises, not data. Build a simple log for every critical-part order with the part, the supplier, the order date, the promised date, and the actual receipt date. After 90 days you will know which suppliers and part types run late, and by how much.
Here is an example. Five orders were each promised in 10 days and arrived in 8, 12, 15, 10, and 22 days. The average actual time was 13.4 days, or 3.4 days (34%) over the promise, and the worst case was 22 days. Plan critical repairs around the worst recent case, not the quote.
Add context to the log: whether the part was in stock at the supplier, whether it shipped from another region, and whether the date slipped once or several times. Those notes show whether a delay is a supplier habit or a one-time event.
Review the log monthly. If a supplier's actual times keep running past the promise, ask for a written commitment, move the part to another source, or raise your stock level. Keep entries by VMRS system so you can see which parts are slipping.
Diversifying Suppliers and Substitutes
Open accounts with a second and third supplier for critical categories before you need them, and place a small order now and then so the account stays active. Suppliers prioritize customers they know, and a new account during a shortage rarely gets priority.
Document cross-references and approved substitutes in your records, including part numbers, source, and the result. A tested alternate is worth much more in an emergency than a search on the day a truck is down. HDJ's OEM and aftermarket sourcing guide covers the trade-offs.
Remanufactured parts can shorten waits for some major components, and cores matter to the price and timing. Check warranty terms before you substitute anything, since coverage conditions come from your warranty contract. HDJ's remanufactured parts guide explains quality and cost considerations.
Use salvage or used parts with caution. They may suit non-critical applications but should be avoided for brake, steering, and other safety systems, and for emissions components where certification matters. Record condition and source, and set a written standard for what you will accept.
Supplier Terms and Communication
Ask suppliers for the terms that matter in a tight market: a committed delivery date, a named escalation contact, how long a quote is valid, and how they handle allocation when stock is short. Put those expectations in writing, and review performance against your delivery log.
Share your forecasts. A supplier that knows your PM schedule and expected volumes can plan around it, and suppliers tend to favor customers who give accurate information. Talk to both the sales contact and someone who can see inventory and orders, so you hear about problems early.
Where you commit volume for priority, protect yourself with price-adjustment language that spells out how tariff changes will be handled, and keep an exit if performance slips. HDJ's vendor management guide covers scorecards and reviews, and its supplier performance and cost control guide covers cost.
Using Maintenance Planning to Buy Time
The cheapest way to handle a long lead time is to start early. Condition checks and PM inspections show wear before failure, so you can order a part while the truck is still running. A planned repair with a part on the shelf beats an emergency repair with a part on order.
Route driver vehicle inspection report defects into the same process. When a defect needs a part that is not in stock, order it the same day and record the expected date on the work order. This keeps the truck, the part, and the repair connected.
Plan for known demand. If a group of trucks will need the same parts at the same mileage, buy them together, and watch your own history for seasonal peaks such as battery, cooling, and heater parts before winter.
What to Do When a Critical Part Is Late
Have a short written plan so nobody improvises on the day. Confirm the new date in writing and ask what caused the delay. Then ask for alternates, check remanufactured and cross-referenced options, and look at what other trucks in your fleet could lend as a donor, if your policy allows it.
Decide who can approve an expedited order, a rental, or a repair using an approved alternate, and set a spending limit so the decision is quick. Tell the customer or dispatcher early and give them a date range, not a single promise you may not keep.
After the event, record what happened in the delivery log and review it. Each late order is data about the supplier and about your stocking decisions. HDJ's emergency parts sourcing guide covers 24/7 options.
Key Recommendation
For the next 90 days, log promised and actual delivery dates on every critical-part order. Plan around your actual numbers, not the quote.
Frequently Asked Questions
Is there still a heavy-duty parts shortage?
The evidence points to a bigger problem with price and predictability than with empty shelves. TMC fleet members ranked cost containment first and parts inflation third in Spring 2026, and the Q1 2026 benchmark showed costs falling. Late parts still happen, so track your own suppliers.
How do tariffs affect heavy-duty parts?
Proclamation 10984 imposes a 25 percent duty on imported medium- and heavy-duty trucks and listed parts, effective November 1, 2025. USMCA-qualifying parts are treated separately until Commerce sets a process. Ask suppliers about origin and price validity, and confirm current duty treatment before relying on a quote.
How should I plan around shortages and lead times?
Log promised and actual delivery dates for critical-part orders for 90 days. Calculate the average and worst-case actual time, and plan critical repairs around the worst recent case. Review the log monthly and act on suppliers that keep running late.
Which parts should a fleet stock?
Stock parts that stop a truck, have one source, or have long quoted lead times, and compare a day of downtime with the carrying cost of the part. Commodity items can be reordered on usage. Avoid parts that fit only one retiring unit or customer.
What should I do when a critical part is late?
Confirm the new date in writing, ask for the cause, and check alternates, remanufactured options, and cross-references. Use pre-set approval limits for expedited orders or rentals, tell the customer early, and record the result in your delivery log.
The Bottom Line
The heavy-duty parts shortage has changed shape. Price, tariff exposure, and unpredictable delivery dates now matter as much as raw availability, and the response to shortages and lead times is the same: measure your own lead times, protect the parts that stop a truck, and set up alternates before you need them.
Heavy Duty Journal's guidance at heavydutyjournal.com, from publisher Michael Nielsen and the HDJ editorial team, is to log promised and actual dates for 90 days, to spend stocking money only where downtime justifies it, and to confirm tariff treatment with your supplier.
As of October 2026, tariff rules, benchmarks, and survey data change, so confirm current figures before relying on them.
Forward This to Your Parts Buyer
Whoever orders critical parts and talks to suppliers can use this plan to cut downtime from late deliveries.
