Best Transmission Cleaner Additive for Automatic Transmissions

#1 · Best Overall

1. Hot Shot's Secret Shift Restore 32 oz

• Form: Liquid
• Container Type: Bottle

Best for: Larger-volume ester formula.

Why it ranks #1: Its description specifically says it dissolves gum and varnish, and the 32 oz bottle supplies the same conditioner format in a larger listed size.

Hot Shot's Secret Shift Restore uses a high-performance ester formula to dissolve harmful gum and varnish while reducing transmission operating temperatures. The 32-ounce bottle offers twice the listed quantity of the brand's 16-ounce version, giving buyers seeking this named cleaning and lubrication approach a larger supplied volume.

The ester formula is described as a transmission lubricant that serves hydraulic, lubricating, and heat-transfer roles, while reducing the coefficient of friction. Separately, the product is said to dissolve gum and varnish that forms on precision transmission components and to reduce operating temperatures. That combination connects deposit action with lubrication and heat management. The listed 32-ounce bottle gives a larger quantity for handling than the 16-ounce Shift Restore listing, though the supplied facts do not provide a dosing amount or service interval.

Skip it if you need a listed treatment for Tiptronic, Manumatic, or semi-automatic gearboxes; XADO EX120 names those transmission types.

Choose the 32-ounce Shift Restore if you want Hot Shot's Secret's stated deposit, lubrication, and temperature functions in the larger listed quantity. Check the product directions for application amount, since the supplied facts do not state one.

Listed on Amazon as: Hot Shot's Secret Shift Restore Transmission Additive, 32 oz

#2 · Broadest Listed Fluid Use

2. Sea Foam Trans Tune

• Weight: 1 lb

Best for: Fluid-system deposit cleaning.

Why it ranks #2: It dissolves gum and varnish and is listed as safe for most automatic transmission fluids, hydraulics, and power steering fluid systems.

Sea Foam Trans Tune dissolves and liquefies gum and varnish in fluid, making it a cleaner option for drivers addressing transmission deposits. It is also listed as safe for conventional and synthetic fluids and for most automatic transmission, hydraulic, or power-steering systems, extending its stated use beyond one fluid application.

Its deposit-cleaning action is paired with cleaning and lubrication of valve bodies, shift actuators, and solenoids, linking fluid cleanup to specific transmission components. The formula also helps control moisture and is stated not to swell seals or harm gaskets, O-rings, or clutch material. Compatibility covers conventional and synthetic fluids and most automatic transmission, hydraulic, or power-steering systems. The 16-ounce container gives a defined amount, while “most” makes the listed compatibility a boundary rather than a universal claim.

Skip it if you require an additive explicitly listed for CVT transmissions; XADO EX120 names CVT compatibility among its gearbox types.

Sea Foam Trans Tune suits owners addressing fluid deposits and component cleanliness across its listed fluid-system uses. Its compatibility says “most” automatic transmissions, so buyers should respect that stated boundary and the product's use directions.

Listed on Amazon as: Sea Foam Trans Tune Transmission Treatment, TT16, 16 oz, Pack of 1

#3

3. Liqui Moly Pro-Line Cleaner

• Weight: 1 kg
• Form: Liquid

Best for: Professional ATF circuit cleaning.

Why it ranks #3: This 1-liter cleaner is specifically for professional automatic-transmission servicing and is described as freeing the ATF circuit of deposits and residues.

Liqui Moly Pro-Line is specified for professional servicing of automatic transmissions, giving transmission technicians a cleaner focused on the ATF circuit. It cleans and frees that circuit from deposits and residues, with the stated aim of supporting optimum gear-shift performance and a residue-free result.

The product's cleaning action targets deposits and residues in the ATF circuit, connecting circuit cleanup to its stated goal of optimum gear-shift performance. Its professional-service designation makes the intended workflow an important distinction for buyers choosing a service product rather than a broadly described consumer additive. The liquid is supplied as a one-liter quantity, providing a defined volume for service use. The listed information does not describe compatibility with CVT or manual transmissions, so its stated scope remains automatic transmission servicing.

Skip it if you need a treatment explicitly listed for CVT as well as automatic gearboxes; XADO EX120 specifies both transmission types.

Liqui Moly Pro-Line fits professional service workflows focused on cleaning an automatic transmission's ATF circuit before pursuing shift performance. Its supplied application is professional automatic servicing, so it is not the broadest fit for other gearbox types.

Listed on Amazon as: Liqui Moly Pro-Line Automatic Transmission Cleaner 20224 1 Liter (1)

#4

4. Hot Shot's Secret Shift Restore 16 oz

• Weight: 16 oz
• Form: Liquid
• Container Type: Bottle

Best for: Automatic and CVT shift care.

Why it ranks #4: It is a transmission additive that reduces operating temperatures and friction, with listed use in automatic and CVT transmissions.

Shift Restore targets metal-to-metal contact while reducing operating temperatures, giving automatic and CVT owners a friction-focused additive for smoother gear changes. Its liquid bottle format keeps the product straightforward to handle, and the listed transmission-specific benefits make it a fit for drivers concerned with shifting feel and operating heat.

The additive reduces the coefficient of friction and minimizes metal-to-metal contact, which supports its stated goal of smoothing gear changes. It also reduces operating temperatures, addressing heat alongside shifting behavior rather than focusing on deposits alone. Hot Shot's Secret lists it for automatic and CVT transmissions, making that transmission scope an important fit check. The 16-ounce liquid bottle offers a defined quantity for handling, while the supplied information does not specify a service interval or dosing instructions.

Skip it if you need a cleaner specifically described as dissolving gum and varnish; Sea Foam Trans Tune names that deposit-cleaning action.

Choose this 16-ounce Shift Restore for an automatic or CVT owner prioritizing reduced friction, heat, and smoother gear changes. Its listed scope is specific to those transmission types, so it is not the pick for a manual gearbox.

Listed on Amazon as: Hot Shot's Secret Shift Restore Transmission Additive, 16 oz

#5 · Best Listed CVT Flush

5. MotorPower Care Transmission Flush

• Weight: 13.7 oz

Best for: Automatic and CVT flush cleaner.

Why it ranks #5: The product is described as a flush cleaner for automatic transmissions and CVTs that dissolves contamination and lubricates while working.

MotorPower Care lists compatibility with all vehicles featuring automatic transmission or CVT, giving those owners a flush cleaner with a clearly stated gearbox scope. The formula is described as dissolving contamination while lubricating as it works, connecting cleaning and lubrication in a single system treatment.

The cleaner's stated action combines dissolving contamination with lubrication while it works in the transmission system, so its function is not limited to loosening deposits. MotorPower Care also presents it for automatic transmissions and CVTs, giving buyers a defined fit range. The title calls out slipping and hesitation, and the features mention cleaning solenoids, useful context for shoppers focused on those issues. The provided information does not state a bottle volume or a specific dosing procedure beyond following instructions.

Skip it if you need a cleaner explicitly described as residue-free and for professional servicing; Liqui Moly Pro-Line names both points.

This is a straightforward candidate for an automatic or CVT owner seeking contamination removal alongside lubrication. Its listed scope does not cover manual gearboxes, and the supplied information leaves the precise application procedure to the instructions.

Listed on Amazon as: MotorPower Care Automatic Transmission Flush Cleaner Stop Slipping and Hesitation Clean solenoids, Certified Product

#6

6. BG Quick Clean for Transmissions

• Weight: 14 oz

Best for: Valve body and filter cleaning.

Why it ranks #6: Its stated cleaning targets include deposits, the valve body, and filter screen, but the listing emphasizes automatic-transmission service.

BG Quick Clean names the valve body and filter screen as cleaning targets, giving transmission-service buyers a component-focused deposit remover. The listing says it quickly removes damaging deposits and cleans other important automatic-transmission components, connecting that cleanup with keeping the transmission operating efficiently.

By naming both the valve body and filter screen, BG Quick Clean gives buyers specific components to associate with its deposit-removal function. The supplied description extends that cleaning to other important automatic-transmission components and says the aim is to keep transmissions operating efficiently. It is also identified as part of a BG Transmission Service, providing service-context rather than a standalone compatibility list. The supplied details do not state a treatment volume or list manual-transmission compatibility.

Skip it if you need a product with a stated 16-ounce quantity and compatibility with hydraulics or power steering; Sea Foam Trans Tune lists both.

BG Quick Clean suits buyers focused on deposit removal at the valve body and filter screen as part of transmission service. Its supplied description centers on automatic-transmission components and does not establish a manual-gearbox use.

Listed on Amazon as: Smilyeez BG Quick Clean for Transmissions PN 106 with Pocket Screwdriver (1)

#7 · Smallest Listed Treatment

7. XADO EX120 Automatic Transmission Fix

• Weight: 10 g
• Form: Liquid
• Container Type: Syringe

Best for: Multi-type gearbox treatment.

Why it ranks #7: The 10 g syringe treatment is listed for automatic, CVT, and several other gearbox types, but emphasizes protection and shifting symptoms over cleaning.

XADO EX120 covers automatic, CVT, Tiptronic, Manumatic, and semi-automatic transmissions, giving owners of several gearbox types one listed treatment option. Its anti-friction modifier is paired with claims of reduced shudder, noise, and vibration, while a protective coating is described as guarding metal parts against future wear.

The product's broad compatibility list can simplify selection for owners of automatic, CVT, Tiptronic, Manumatic, or semi-automatic gearboxes. XADO says its anti-friction action helps reduce shudder, noise, and vibration, addressing several shifting-related symptoms together. The treatment also claims to rebuild and restore metal parts and apply a durable protective coating, with protection stated for 60,000 miles. Supplied as a 10-gram liquid syringe, its format is compact, though the available facts do not specify dosing workflow.

Skip it if you want a deposit cleaner with a stated 16-ounce bottle; Sea Foam Trans Tune specifies that amount and names gum and varnish removal.

Consider EX120 if you need a treatment listed for varied gearbox types and want its stated anti-friction and wear-protection functions. The supplied facts identify a 10-gram syringe, so check the product directions for your application workflow.

Listed on Amazon as: XADO EX120 Automatic Transmission Fix – Treatment for CVT & Other Gearbox Types | ATF Additive & Protectant – Reduces Sticking, Shudder and Slipping

#8

8. Lucas Oil Transmission Fix 12 oz

• Weight: 1.5 lb
• Form: Liquid
• Container Type: Bottle

Best for: No-drain fluid addition.

Why it ranks #8: Its no-solvent formula can be added without draining fluid, but the listed focus is slipping, hesitation, rough shifting, and seal leaks.

Lucas Oil Transmission Fix can be added to existing fluid without draining any out, enabling an addition-based workflow for owners who want to avoid a fluid drain. Its no-solvent formula also lowers operating temperatures and stops foaming, while the description identifies worn-transmission slipping, hesitation, and rough shifting as target concerns.

Because it can be added to existing fluid without draining, the product supports a simpler addition workflow than a treatment requiring fluid removal. Lucas says its no-solvent formula lowers operating temperatures and stops foaming, giving the additive two stated operating effects alongside its described aim of addressing slips, hesitation, and rough shifting in worn transmissions. The description also says it can help eliminate most seal leaks. The listing identifies a 12-ounce bottle, but supplies no specific dosing amount or service interval.

Skip it if you want an additive that explicitly dissolves harmful gum and varnish; Hot Shot's Secret Shift Restore lists that cleaning action.

Lucas Transmission Fix fits owners of worn transmissions seeking a no-drain addition and the listed temperature and foaming benefits. Its supplied description emphasizes shifting symptoms and seal leaks, not a specific deposit-cleaning mechanism.

Listed on Amazon as: Lucas Oil Transmission Fix,Bottle,Red,12 oz. 10009 – 1 Each

#9

9. Lucas Transmission Fix

• Weight: 1.6 lb
• Form: Liquid
• Container Type: Bottle

Best for: Worn-transmission shift support.

Why it ranks #9: This no-solvent product targets slipping, hesitation, rough shifting, and seal leaks rather than cleaning deposits, making it the least direct fit.

Lucas Transmission Fix combines a no-solvent formula with the ability to add it to existing fluid without draining, supporting a direct maintenance workflow. Its description targets slipping, hesitation, and rough shifting in worn transmissions, while the listed benefits also include lower operating temperatures and reduced foaming.

The no-drain addition method lets owners add the product to existing transmission fluid rather than first removing fluid, as the listing expressly states. Its no-solvent formula is associated with lower operating temperatures and stopping foaming. The description further says it addresses slips, hesitation, and rough shifting in worn transmissions and can eliminate most seal leaks. It is also listed for light-duty manual transmissions to increase shifting ease, a distinct use from the general transmission preventative-maintenance claim.

Skip it if you need an additive explicitly listed for CVT use; XADO EX120 names CVT among its compatible transmission types.

This Lucas formula suits owners of worn transmissions who want a no-drain addition, including light-duty manual-transmission users seeking easier shifting. The manual application is specifically described as light duty, which sets a clear boundary.

Listed on Amazon as: Lucas Transmission Fix