Dorman Truck Parts Procurement Checklist: 6 Steps Before You Place the Order

Who This Checklist Is For

This checklist is for anyone sourcing Dorman parts for a company or fleet. Transmission oil cooler lines, Cummins N14 fuel pumps, alternator brushes, wheel bearing assemblies — these are the kinds of parts I buy, and these are the six steps I use to evaluate suppliers before I commit. It's not a consumer shopping guide. It's a supplier vetting process that keeps me from explaining to finance why the invoice came in 30% above the quote.

Step 1: Verify the Part Number Before You Compare Prices

"Dorman" is a brand, not a spec. A single transmission oil cooler line can have three or four variants depending on the truck's configuration. Before anyone quotes you anything, confirm the exact part number — the one stamped on the old part, or from the VIN if you're doing a fresh install.

When I first started managing these orders, I assumed writing "Dorman transmission oil cooler line" was specific enough. It wasn't. Six weeks later I had a part in the warehouse that fit nothing, and a line down at the shop waiting on the right one.

Step 2: Calculate Total Landed Cost, Not Unit Price

Unit price is the smallest number on the page. Before comparing any two suppliers, put these side by side:

• Shipping (flat rate? free over a threshold? hazmat surcharge?)
• Core charges (almost always present on alternators and hub assemblies)
• Restocking fees if the part comes back
• Rush shipping penalties (a stuck truck makes this worse by the hour)
• Payment terms — net 30 versus a company card changes your true cost

I've seen an $85 quote come in at $112 landed. The $95 "all-in" quote — shipping, core return, everything — turned out to be the cheaper option. It took me about 18 months to actually build the habit of checking all six line items every time. Before that I was missing one or two on every comparison.

Step 3: Confirm What "In Stock" Really Means

Plenty of distributors say "in stock" when they mean it's sitting in a regional warehouse two states away. Before a delivery promise becomes a promise, ask:

• Which warehouse does it ship from?
• What's standard transit from that location?
• If I order today, what's the ship date?

A wheel bearing is not something you gamble on with "it should arrive." I learned that the hard way after a truck sat for three days waiting on a bearing that was supposed to be there two days earlier. Now I get ship dates in writing. If it's not in an email, it doesn't count.

Step 4: Ask About Core Charges and Return Windows Up Front

If you're buying alternators or hub assemblies, core charges can add 20–30% to the sticker. Ask:

• Who sets the core charge — the supplier or the factory?
• How many days do I have to return the old part?
• Does the old part need to be in sellable condition, or is a worn one accepted?

I had a supplier not mention core charges once. It cost me $180 out of my own budget line. That's now the first question I ask on every quote.

Step 5: Check the Paper Trail, Not Just the Review Score

Star ratings don't mean much. What helps:

• How many price changes have they made in the last 12 months? (Ask them, then cross-check.)
• Call two other buyers who've used them — not reference accounts they hand you.
• Pull their business registration — if the address keeps moving, that's a flag.

I don't care if a supplier has a brand. I care if they're likely to have a different phone number tomorrow.

Step 6: Get Verbal Commitments Into Email

If they say "Yeah, no problem, it'll be there" on the phone, have them put it in a follow-up email. If they won't confirm in writing, you have your answer.

I thought we had a good enough relationship with a long-running supplier that verbal agreements were fine. Then one verbal deadline got forgotten — verbal ones always do. Now I ask for written confirmation regardless of how long we've worked together.

Common Mistakes

• Comparing unit price only. Total landed cost is the real number.
• Accepting "in stock" without a ship point. Where it ships from matters more than whether it exists.
• Skipping core charge questions. A $180 lesson will make you remember.
• Trusting verbal deadlines. If it's not confirmed in writing, it wasn't agreed to.
• Assuming "Dorman" means fitment. The part number is the only spec that matters.

If you're holding a wheel bearing job and the shop tells you the truck "can still drive" — don't make that call yourself. Write it into the purchase order as a note. By the time that bearing seizes, the time you saved won't have saved anything.