Choose transmission additives only after identifying your transmission, the required fluid and whether the vehicle manual permits additives. A conventional automatic, belt or chain CVT, hybrid eCVT and dual-clutch gearbox can have different requirements. Have persistent shudder, slipping or delayed engagement diagnosed before treating the fluid.
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Transmission additives by fluid type and label
| Product | Verified label details | Use and limits | Listing |
|---|---|---|---|
| Prolong PSL15000 Transmission Treatment | 8 fl oz | Manufacturer describes conventional automatic and manual applications. | Check Amazon availability |
| Lucas Transmission Fix 10009 | 24 fl oz | Maker advises against use in CVT or dual-clutch transmissions. | Check Amazon availability |
| Hot Shot’s Secret Shift Restore | 32 fl oz, HSSTSE32Z per retailer | Maker lists automatic and CVT use, around 1.5 fl oz per US qt. | Check Amazon availability |
| Lubegard Platinum ATF Protectant 63010 | 10 fl oz | Maker lists 1 fl oz per US qt of total capacity for normal ATF use. | Check Amazon availability |
| Lubegard Instant Shudder Fixx 19610 | 2 fl oz | Friction treatment marketed for torque-converter lockup shudder. | Check Amazon availability |
| Lubegard CVT Recharge & Protect 67010 | 10 fl oz | Belt or chain CVTs that require CVT fluid. Maker lists 1 fl oz per US qt of total capacity. | Check Amazon availability |
| Sea Foam Trans Tune TT-16 | 16 fl oz | US directions cover conventional automatic transmission fluids. Regional CVT guidance differs. | Check Amazon availability |
| K&W Trans-X High Mileage 402916 | 16 fl oz per bottle | Maker identifies automatic transmission use and excludes CVT fluids. | Check Amazon availability |
Product listings
- Prolong PSL15000 Transmission Treatment Check Amazon availability
- Lucas Transmission Fix 10009 Check Amazon availability
- Hot Shot’s Secret Shift Restore Check Amazon availability
- Lubegard Platinum ATF Protectant 63010 Check Amazon availability
- Lubegard Instant Shudder Fixx 19610 Check Amazon availability
- Lubegard CVT Recharge & Protect 67010 Check Amazon availability
- Sea Foam Trans Tune TT-16 Check Amazon availability
- K&W Trans-X High Mileage 402916 Check Amazon availability
Identify the transmission and fluid first
- Use the vehicle manual, build information or a service department to confirm the transmission code. Record the required fluid specification and whether the vehicle maker permits supplemental treatment.
- Match the exact product to that transmission and fluid. The Ford E-Series manual is an example of an automaker explicitly prohibiting supplemental transmission additives.
- Where treatment is allowed, follow the label and the vehicle’s fluid-level procedure. A label can dose by total capacity, which differs from the amount drained in a partial service. Check the required fluid temperature and avoid overfilling.
When to seek transmission diagnosis
Arrange service for a warning light, loss of drive, recurring slip, a fluid leak or a strong burning smell. A technician can compare fault codes, fluid condition and engagement behavior with the vehicle’s service procedure. For a vehicle that loses drive or develops a severe leak, follow the manufacturer’s towing guidance.
Identify the system before adding any fluid or treatment. The power steering leak guide covers a separate hydraulic system. For maintenance access and related safety, see the car jack guide. If the symptom occurs only while braking, the brake lubricant guide covers brake service applications. Use service information to diagnose the source of the noise or vibration.
Prolong PSL15000 Transmission Treatment
Prolong identifies the 8-fl-oz bottle. Its general automatic-transmission wording does not establish fit for CVT or dual-clutch designs. Check the exact fluid and application with the vehicle and additive manufacturers.
Lucas Transmission Fix 10009
Lucas lists fit and dosing notes for this product. Account for additive volume when checking fluid level. For recurring slip, check fluid loss, faults and possible internal wear with a shop.
Hot Shot’s Secret Shift Restore
Hot Shot’s Secret’s directions call for displacing an equal volume of transmission fluid. The retailer matches the linked bottle. Confirm the vehicle permits it and check the specified fluid level procedure.
Lubegard Platinum ATF Protectant 63010
Lubegard excludes CVTs and specified older Ford Type F applications. Use the vehicle-required base fluid and verify the exact Type F restriction before selecting it.
Lubegard Instant Shudder Fixx 19610
Lubegard excludes CVT, dual-clutch and specified older Ford Type F applications. A shake can have causes outside the torque converter. Diagnose the symptom before treating it.
Lubegard CVT Recharge & Protect 67010
The Lubegard CVT directions specify belt or chain drives and a maximum of 2 fl oz per quart. Check the vehicle’s approval and capacity. A hybrid eCVT name does not establish a matching belt or chain design.
Sea Foam Trans Tune TT-16
The US instructions describe one can per fluid interval and at least 30 miles of circulation before a fluid change. A US answer for a Nissan CVT permits use, while the Canadian FAQ excludes CVTs. Confirm the exact vehicle, label and market before considering CVT use.
K&W Trans-X High Mileage 402916
CRC lists the 16-fl-oz high-mileage formula and the CVT exclusion. Check the seller’s pack quantity and do not use the bulk pack as the treatment dose. A fluid leak or repeated loss of engagement warrants diagnosis.
Product documentation
- Prolong Transmission Treatment and Lucas Transmission Fix
- Hot Shot’s Secret Shift Restore
- Lubegard Platinum, Instant Shudder Fixx and CVT Recharge & Protect
- Sea Foam automatic transmission fluid instructions and CRC Trans-X High Mileage
FAQ
Can I add a conventional ATF treatment to a CVT?
Check the transmission model, exact fluid and owner’s manual. Some products explicitly exclude CVT use. Choose a CVT-labeled treatment only when the vehicle manufacturer permits it.
Does a CVT treatment also fit a hybrid eCVT?
Check the design and service instructions. Lubegard CVT Recharge & Protect specifies belt or chain CVTs that require CVT fluid.
Can an additive fix transmission shudder?
A vibration can originate in the torque converter or elsewhere in the vehicle. Diagnose recurring shudder before choosing a friction treatment.
Should I dose from the drain quantity or total capacity?
Use the basis on the product label. Some products specify total transmission capacity. Check the final level with the vehicle maker’s procedure.
What if I am losing drive or seeing a leak?
Follow the vehicle maker’s safety and towing guidance and arrange service. A leak or loss of engagement needs diagnosis.
Product photos and listings
| Product | Photo and listing |
|---|---|
| Prolong PSL15000 Transmission Treatment | Check Amazon availability |
| Lucas Transmission Fix 10009 | Check Amazon availability |
| Hot Shot’s Secret Shift Restore | Check Amazon availability |
| Lubegard Platinum ATF Protectant 63010 | Check Amazon availability |
| Lubegard Instant Shudder Fixx 19610 | Check Amazon availability |
| Lubegard CVT Recharge & Protect 67010 | Check Amazon availability |
| Sea Foam Trans Tune TT-16 | Check Amazon availability |
| K&W Trans-X High Mileage 402916 | Check Amazon availability |
Sources checked on November 11, 2026.
