3
verified units in stock
2020 Used Chevy Silverado 3500 Transmissions For Sale
Three verified 2020 Chevy Silverado 3500 transmissions are in stock and ready to freight. Each one is listed against the 2001-Up Silverado 3500 span, each is an automatic, and each sits behind a 6.6L — so the badge on the tailgate will not narrow this page down for you. Fuel and drivetrain will. Every unit is VIN-matched to your truck, shift-tested under load by ASE-certified technicians and photographed before it ships, backed by up to a 3-year warranty and 30-day money-back. Free freight to all fifty states.
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Shift-Tested & Verified
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Free Nationwide Shipping
2020 Silverado 3500 Transmission Fitments In Stock
Every 2020 Silverado 3500 transmission we hold, one card per build. All three share a displacement and a gearbox type, so what separates them is what the truck burns and how many wheels it drives. Pick the card that reads like your truck, then let the VIN confirm it at the order step.
Looking for a diesel 4x2? We stock the gasoline truck in both drivetrains, but the diesel only in 4x4 today — text us the VIN and we will source the right one rather than ship you a box that bolts up and fails. Need the other half of the job? 2020 Chevy Silverado 3500 engines are listed separately, or go back up to all 2020 Chevy transmissions.
Why Buy a 2020 Chevy Silverado 3500 Transmission from Auto Power Source
Each transmission here was pulled from a low-mileage 2020 Silverado 3500 donor, logged against that truck's VIN on arrival, and stored indoors in a climate-controlled warehouse instead of a yard. Nothing on this page has been rebuilt or reshelled — it is original Chevy hardware, sold as what it is. Before a unit is listed, our ASE-certified technicians cycle it through every gear and then drive it with weight behind it, because a transmission out of a working truck can pass a no-load bench check and still be finished.
One detail on this page is worth more than it looks: every 2020 Silverado 3500 unit we list carries the 2001-Up span, where our 1500 and 2500 listings run from 1999. That is the interchange family the part belongs to, and it is the sort of thing a cross-reference table gets wrong at two in the morning. After that, the order is simple. Fuel first — two of these trucks are gasoline, one is diesel, and no amount of matching litres makes those gearboxes interchangeable. Drivetrain second: gasoline in 4x2 or 4x4, diesel in 4x4 only. Text us the VIN and we will name which of the three is yours — or tell you honestly that it is one we have to source.
📱 Fastest way to match: text us your VIN, get options in minutes.Text Your VIN →
Your 2020 Silverado 3500 Transmission Options: Compared
When the transmission goes on a 2020 Silverado 3500, there are four routes open to you. The honest comparison:
← Swipe sideways to see all columns →
| Option |
Cost |
Reliability |
Warranty |
Fitment Match |
| Used OEM (this collection) |
$$$ Best Value |
High |
Up to 3 years |
VIN-matched |
| New OEM (dealer) |
$$$$$ 2-4× more |
High |
Manufacturer |
Exact |
| Aftermarket / Reman |
$$$$ |
Varies |
6-12 mo |
May adapt |
| Junkyard |
$ Cheapest |
Unknown |
None |
DIY |
Tested used OEM is where the value sits — factory hardware with a real warranty attached, without the dealer markup on a new-in-box unit.
2020 Silverado 3500 Transmission Buying Guide
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Check the span before the specs. Our 2020 Silverado 3500 transmissions are listed on the 2001-Up span, while the 1500 and 2500 pages run from 1999. If you are working off a generic interchange chart, confirm you are reading the 3500 column and not the row above it.
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Then settle fuel — it decides everything downstream. Gasoline or diesel is the real first cut here. Both are 6.6L, so litres will not tell them apart; on most other 2020 Chevys displacement does that work, and on this truck it does none of it.
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Then 4x2 versus 4x4. We hold the gasoline truck in both, and the diesel in 4x4 only. A 4x2 unit and a 4x4 unit differ at the output and the transfer interface — matching the engine perfectly does not make them the same part.
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On the diesel, order from the option code. Our diesel listing carries opt MGM and ID OMKF. These trucks were built to order, and the codes — not the trim badge, not the model year — are what confirm the match.
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Ask for the donor VIN. We release it on request for any Silverado 3500 transmission in stock, so you can check mileage and history for yourself instead of taking our word for it.
Our ASE-certified technicians verify every one of these points against your VIN before any transmission ships.
📞 Not sure whether your 3500 left the line gasoline or diesel? Talk to our team live, 24h Mon-Sat.Call 1-877-313-8995
Frequently Asked Questions
What is the warranty on a 2020 Silverado 3500 transmission?
Up to 3 years, depending on the specific unit. The exact term is shown on each product page.
What does shift-tested mean?
ASE-certified technicians run the unit through its full gear range under load and check for slip, flare and harsh engagement before it is cleared for sale.
How long until delivery?
Prep and ship time is 3-5 business days. Transit time is 2-3 business days via freight carrier after dispatch.
Can I see photos before I buy?
Yes. Multi-angle photos of the actual unit are sent before payment.
Do I need my VIN?
On this truck, effectively yes. All three units are 6.6L automatics, so displacement cannot separate them — the VIN is what settles gasoline versus diesel and 4x2 versus 4x4, and it is the only thing we will match your order against.
What if I do not approve the photos?
Every dollar back — no restocking fees, no return freight charges.
Why is this cheaper than a dealer replacement?
It is used OEM out of a low-mileage donor Silverado 3500 — the same Chevy engineering, minus the new-part markup.
When can I reach customer service?
24 hours a day, Monday through Saturday.
46,000+
engines + transmissions shipped
0%
fitment-related returns
All 50
states covered, free freight
Excellent
Customer Reviews
rated on Trustpilot
Our 6-Step Inspection & Shipping Process
No 2020 Silverado 3500 transmission reaches this page until it has cleared all six:
1. VIN-MatchingYour VIN answers the two questions this listing turns on: gasoline or diesel, and 4x2 or 4x4. We read it rather than guess it.
2. Tested & VerifiedASE-certified technicians shift-test the unit through every gear, watching for slip, flare and harsh engagement.
3. Shift & Road VerificationDriven under load, not idled on a bench. A worn converter stays polite at no-load and only tells the truth with weight behind it.
4. Visual InspectionCase, bellhousing, pan, cooler lines, harness connectors and every mounting point go under the light.
5. Photograph & CatalogMulti-angle photos reach your inbox BEFORE the freight is booked. Your approval is what moves the pallet.
6. Palletize & ShipStrapped to a heavy-duty wooden pallet and freighted to your door at no charge.
What Our Customers Say
Rated Excellent by our customers on Trustpilot.
★★★★★
Transaction was perfect
"Found me the right engine at a great price. Got it in 2 days and installed the car the next day. Runs absolutely beautiful."
— Kevin Graham, 2026-04-29
★★★★★
Repeat customer
"AutoPowerSource is a great company. I've used them several times for used motors. Low mileage when other companies gave up."
— Curtis Haines, 2025-12-23
★★★★★
Highly recommend Mike
"Mike reached out first thing in the morning regarding my inquiry for a used engine. Very informative and helpful."
— Beatrice, 2026-03-31
★★★★★
Great experience
"Daisy kept me in the loop every step. My original engine was damaged before shipping; she found a different one quickly."
— Bryan Perkins, 2026-03-25
Our Photos-Before-Shipment Guarantee
Before any 2020 Silverado 3500 transmission leaves our warehouse, we send you multi-angle photographs. You approve. If you do not approve, you get every dollar back — no questions, no restocking fees, no return freight charges. That sits on top of 30-day money-back and up to a 3-year warranty.
✉ Email Us at info@autopowersource.com
