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2018 GMC Sierra 1500 · Torque converter replacement
2018 GMC Sierra 1500 torque converter replacement cost
A 2018 GMC Sierra 1500 torque converter replacement typically costs $1,070 to $2,355 at an independent shop, parts and labor included across its engine options. The torque converter itself runs $200 to $650, and the job takes 6 to 9 hours. Prices updated September 2026.
Estimated cost, selected engine
$1,070 to $2,070
Charlotte, NC area
Prices updated September 2026
Which engine? They price differently, so pick yours for a closer number.
Torque converter (part)
$200 to $650
Labor (6 to 9 hours)
$780 to $1,485
ATF (11-13 qt), gasket, flush
$90 to $220
2018 GMC Sierra 1500 torque converter replacement: parts and labor
Labor runs $780 to $1,485 (the job takes 6 to 9 hours at typical independent-shop rates), and the torque converter itself typically costs $200 to $650 for the 2018 GMC Sierra 1500, plus $90 to $220 in atf (11-13 qt), gasket, flush. Prices updated September 2026.
| Engine | Parts | Labor | Estimated total |
|---|---|---|---|
| 4.3L V6 | $200 to $450 | $780 to $1,400 (6.0 to 8.5 hrs) | $1,070 to $2,070 |
| 5.3L V8 | $200 to $625 | $780 to $1,400 (6.0 to 8.5 hrs) | $1,070 to $2,245 |
| 6.2L V8 | $250 to $650 | $845 to $1,485 (6.5 to 9.0 hrs) | $1,185 to $2,355 |
Coverage note: 5.3L eAssist mild hybrid (MHEV) excluded: it uses a different 8 speed converter (GM 24297075, $673) plus hybrid system handling, and 2018 volume is negligible. No diesel was offered in the 2018 Sierra 1500.
Dealers price this repair from the GM playbook: the $611 list GM new 8L90 converter (or a reman transmission exchange around $5,400 installed), Mobil 1 LV ATF HP at dealer markup, and $180 to $220 per hour labor, which is how forum posters end up with $2,800 to $3,500 dealer quotes. Generic estimators run the other direction: RepairPal style national averages of $600 to $2,000 and the often quoted 4 to 5 hour labor figure undershoot this truck because they assume a car with an easier trans drop and skip the 13 quart Dexron HP refill and TCM relearn the 8L90 requires. The independent shop reality for this specific truck sits between those two, right in the ranges above.
Where these numbers come from
- Estimate ranges: a hand-verified research pass for this exact vehicle and repair, cross-referenced across 14 independent sources (parts retailers, labor guides, and published shop pricing), completed September 2026.
- Recall and complaint data: NHTSA (National Highway Traffic Safety Administration) records for the 2018 GMC Sierra 1500 specifically, filtered to transmission relevance and refreshed daily from the federal API.
- Local prices: real, accepted quotes from verified Fixxr marketplace jobs, published per metro once five verified jobs of this type have closed. Never estimates dressed up as transactions.
Not included in the estimate: Full rebuild or reman transmission exchange (the $3,500 to $5,400 path when debris is found), Pump or valve body replacement if converter clutch material has circulated, Transmission cooler replacement or auxiliary cooler line flush kit, Billet or performance upgrade converters (Circle D and similar run $600 to $1,500 part alone), The TSB 18-NA-355 fluid exchange only attempt ($250 to $400) that should precede converter replacement on 8L90 shudder, Diagnostic fee, taxes, and shop supplies percentages.
What actually goes wrong on this exact vehicle
Federal safety data for the 2018 GMC Sierra 1500, filtered to the transmission specifically.
0
transmission recalls
103
transmission owner complaints
Real owner report, verbatim from NHTSA:
“The transmission has always been rough. It has now gone out at 75,000 miles. This transmission issue really seemed to get worse about 50,000 miles. But when I called the dealer, they said they were backed up and couldn't get to it for 9-12 weeks (Covid excuses at that point). Then, it really had an issue going down a large grade into [XXX] . But the issues seemed fairly intermittent. I had an independent shop who said it was hard to tell if it was intermittent. They didn't find metal shavings at the time. ADDITIONALLY, it has also always been a little rough driving. A mechanic looking at it today told me there are no sway bar links at all. This truck has not been modified. This had to have come off the line faulty. Among all the other things. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)”
Get the failure confirmed with a real diagnosis before you approve the repair, so you fix the part that actually failed.
Recall fixes are free at the dealer. Everything else deserves a fair price.
Source: NHTSA (National Highway Traffic Safety Administration), recalls and complaints for the 2018 GMC Sierra 1500. Refreshed periodically.
Not sure what’s wrong?
A shudder or slip can be the torque converter, the transmission itself, worn mounts, or even misfires. Describe what your truck is doing and our free diagnostic tool narrows it down before you spend a dollar.
Diagnose it freeKnow what you need?
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Get connected with a mechanicHow your torque converter works
The torque converter is the fluid coupling between the engine and the automatic transmission in your 2018 GMC Sierra 1500. It lets the engine keep spinning at a stoplight, multiplies torque when you pull away, and at cruising speed an internal lockup clutch grips solid to stop wasting fuel. That clutch is the part that wears out, and because the converter bolts on between the engine and transmission, replacing it means removing the transmission, which is why labor is most of the bill.
Four signs it’s the torque converter
Shudder at steady speed
A rumble-strip vibration at light throttle on the highway. The classic sign of a worn converter lockup clutch.
RPM flares, truck doesn't
Engine revs climb without matching speed. The converter or transmission is slipping instead of gripping.
Delayed or harsh engagement
A pause or clunk when shifting into drive or reverse, especially cold.
Hot, dark, or burnt fluid
A slipping converter cooks the fluid. Dark color or a burnt smell means friction material is circulating.
The free check: on a quiet road, hold a steady 45 to 55 mph at light throttle. A vibration that appears in that zone and fades when you accelerate or lift off points at the converter clutch. Mention exactly when it happens to your shop; it is the single most useful thing you can tell them.
What a torque converter replacement is like on the 2018 GMC Sierra 1500
Which transmission you have decides half the bill, and on the 2018 Sierra it splits by trim, not just engine. The 4.3L LV3 V6 runs the 6L80 six speed only. The 5.3L L83 runs the 6L80 on base and SLE trucks but gets the 8L90 eight speed (RPO M5U/M5X) on SLT and Denali. The 6.2L L86 is 8L90 only. Check the RPO sticker in the glovebox before pricing anything: a GM new six speed converter lists at $314 to $370 on RockAuto while the eight speed unit (GM 24297076) is $611 plus a $100 core, so two otherwise identical 5.3 crew cabs can be $250 apart on parts alone.
If your truck is an 8L90 and the symptom is the 25 to 50 mph rumble strip shudder, do not let anyone sell you a converter first. GM TSB 18-NA-355 covers exactly this on the 2015 to 2019 trucks, and step one is a full fluid exchange with Mobil 1 Synthetic LV ATF HP, the blue label Dexron HP fluid, about 13 quarts at $14 to $16 each. A flush runs $250 to $400 and cures early shudder in most cases because the failure mechanism is water absorption in the original fluid glazing the TCC lining, not a broken converter. Only a shudder that survives the exchange, or one that has been grinding away for tens of thousands of miles, actually needs the converter in this estimate.
There is no converter access shortcut on the K2XX platform: the whole transmission comes out. Figure 6 hours on a 2WD V6 truck and up to 8.5 to 9 hours on a 4WD, which adds the transfer case, front driveshaft, and skid plate to the job. The 8L90 also wants a TCM fast relearn after reassembly (the adaptive shift values are garbage against a fresh converter), which is why eight speed trucks sit at the top of the labor spread. The transmission electrical connector and cooler line fittings on these trucks are one time use prone, so a $20 to $40 small parts line on the invoice is normal, not padding.
Parts pricing anchors from the RockAuto catalog for this exact truck: TC Remanufacturing eight speed converters at $208 to $257 (watch the stiff $225 refundable core), LuK TC0017 for the 6L80 at $443 with mounting bolts included, GM Genuine six speed units 19435562 and 19435460 at $314 to $370, and the GM new eight speed 24297076 at $611. On the 8L90 specifically, insist on the current GM revision or a reman built with the updated clutch lining; installing an old stock converter with the original lining just restarts the shudder clock.
Forum quotes of $2,500 to $3,500 for this job on Silverado and Sierra boards are almost never a straight converter swap. Read the fine print and there is a pump, a valve body, a billet upgrade converter, or a full rebuild in there, usually because the shop found clutch material in the pan. That is the real caveat on a high mileage 8L90: if shudder ran long enough to shed friction material through the cooler circuit, a converter only repair fails again, so a good shop will pull the pan first and quote from what is in it. A clean pan and a converter R and R at an independent lands in the $1,100 to $2,400 window this estimate shows.
Estimate note: these are researched independent-shop ranges, not a guaranteed quote. The only exact number is one from a shop that has seen your car.
Frequently asked questions
How much does a 2018 GMC Sierra 1500 torque converter replacement cost?
A 2018 GMC Sierra 1500 torque converter replacement typically runs $1,070 to $2,355 at an independent shop, parts and labor included. The torque converter itself is $200 to $650, labor makes up most of the rest, and the job takes 6 to 9 hours.Why does the price change with the engine?
The 2018 GMC Sierra 1500 came with more than one engine, and they do not share the same part or the same access. A tighter engine bay or extra teardown adds labor hours, and the part price moves too. Sites that show one national number flatten that out. Pick your engine on the estimate above for a closer figure.What are the signs of a bad torque converter?
The classic sign is a shudder at steady highway speed under light throttle, a rumble-strip vibration that comes and goes as the converter's lockup clutch grabs and slips. Others: engine RPM flaring up without the truck speeding up, a delayed or harsh clunk into drive, a whine that changes with gear, and transmission temperature climbing on grades. These symptoms overlap with internal transmission problems and even engine misfires, so get a real diagnosis before paying for either.Can I drive my GMC with a bad torque converter?
Briefly, but it gets more expensive the longer you wait. A slipping converter sheds clutch material into the transmission fluid and runs hot, and that debris circulates through the entire transmission. Caught early, this can be a converter and fluid job. Ignored, it becomes a full rebuild at several times the price. If it shudders occasionally, book the repair soon; if it slips hard or overheats, stop driving it.Should the transmission be rebuilt at the same time?
Fluid condition is the tell. If the fluid is clean and the failure is isolated to the converter clutch, a converter-only replacement is a legitimate fix, and the labor is already paid since the transmission comes out either way. If the fluid is dark, smells burnt, or carries metal or friction material, converter debris has been through the whole unit and a reputable shop will recommend a rebuild instead of bolting a new converter to a dying transmission. Ask to see the fluid and the pan.How long does a torque converter last?
Usually the life of the transmission, commonly 100,000 to 200,000 miles. The weak point is the lockup clutch inside the converter, which wears like any friction clutch, and worn-out fluid accelerates it. Regular transmission fluid service is the cheapest way to extend converter life, and it is also what keeps a future repair converter-only instead of a rebuild.Are there recalls on the 2018 GMC Sierra 1500?
Yes, NHTSA lists 7 recalls for the 2018 GMC Sierra 1500. Recall repairs are done free of charge at a franchised dealer for that brand, so it is worth checking your VIN before paying a shop for related work.
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