How Much Does It Cost to Replace a Synchro?

Expect to pay about $1,000–$2,500 to replace a single synchro in a manual transmission in the U.S., with multi-gear or full-rebuild jobs commonly ranging $1,500–$4,000 and performance/exotic models reaching $3,500–$7,000+. The parts themselves are relatively inexpensive—often $20–$200 per synchronizer ring—but labor (8–20+ hours at $110–$250/hour) dominates the bill because the transmission must be removed and disassembled. Below, we explain what drives the price, typical scenarios, symptoms, alternatives, and how shops approach the job.

What a Synchro Is—and Why It’s Expensive to Replace

Synchronizers (or “synchros”) are friction components in manual transmissions that match gear speeds to allow smooth, grind-free shifts. Replacing one isn’t like swapping a belt: the transmission must be removed from the car, opened on a bench, and reassembled with precise tolerances. That teardown/rebuild time—plus fresh bearings, seals, fluid, and sometimes damaged gears or hub/sleeve parts—is where most of the cost comes from. Note: Automatics and CVTs don’t use synchros.

Typical Price Ranges

The following estimates reflect 2025 U.S. shop rates and common scenarios. Actual costs vary by vehicle, region, shop type, and the condition of internal parts.

• Single-gear synchro replacement (economy/manual, minimal collateral damage): $1,000–$2,500
• Multiple synchros or partial rebuild (bearings/seals, hubs/sleeves as needed): $1,500–$4,000
• Performance/exotic or AWD with complex removal: $3,500–$7,000+
• Used transmission swap (unit $400–$1,800; install/fluids $600–$1,200): $1,200–$3,200 total
• Rebuilt/reman transmission (unit $1,800–$3,800; install $800–$1,200): $2,600–$5,000 total
• DIY parts only (rings $20–$200 each; hub/sleeve $150–$400; bearings/seals $150–$400; fluid $50–$120): $400–$1,200+ in parts, plus specialty tools

These ranges show why shops often recommend a broader refresh once the case is open: the marginal labor for additional internal parts is relatively small compared with the base tear-down and reassembly time.

What Drives the Cost

Several variables influence whether your bill lands at the low or high end of the range.

• Labor hours: 8–22+ hours depending on engine/trans layout (FWD vs. RWD vs. AWD), subframe drops, and packaging
• Shop rate: Independent shops often charge $110–$160/hr; dealerships in major metros can run $170–$250/hr
• Parts scope: A single blocker ring vs. rings plus hub/sleeve, shift forks, bearings, seals, or damaged gears
• Vehicle specifics: Performance gearboxes (triple-cone/carbon-lined synchros) and AWD drivetrains are costlier
• Parts availability: OEM-only or backordered parts can add cost and time
• Region: Urban coasts typically cost more than rural areas; taxes and shop fees vary
• Warranty expectations: Reman units or full rebuilds often carry better warranties than piecemeal repairs

In short, the more complex the removal and the more internal wear discovered, the higher the final invoice.

Symptoms That Point to a Bad Synchro

Before authorizing an overhaul, confirm that the issue is actually the synchro and not the clutch or shifter linkage.

• Grinding or crunching when engaging a specific gear (often 2nd or 3rd), especially at higher RPM
• Gear that resists engagement unless you double-clutch or rev-match
• Downshifts that balk or pop out under load
• Shifting improves notably when you slow the input shaft (e.g., pausing in neutral, double-clutching)
• Noisy shifts persist despite a healthy clutch and correct gear oil

Because clutch drag, worn bushings, or incorrect fluid can mimic synchro failure, accurate diagnosis saves money and downtime.

Alternatives and Ways to Save

Depending on your vehicle, usage, and budget, there may be less costly steps to try or different repair paths to consider.

• Rule out clutch and hydraulics: A dragging clutch can cause grinding. Check pedal free play, master/slave cylinders, and bleeding.
• Service the fluid: Use the manufacturer-specified viscosity and GL rating (many manuals need GL-4, not GL-5). Fresh, correct oil can modestly improve shift quality.
• Shifter/linkage/bushings: Worn bushings or misadjusted cables can hinder engagement.
• Used gearbox swap: Faster and sometimes cheaper than a bench rebuild; risk is unknown history and limited warranty.
• Rebuilt/reman unit: Higher upfront cost but predictable results and a real warranty.
• Targeted vs. full rebuild: If one gear is affected and internals are otherwise healthy, a focused repair can save; if wear is widespread, a full refresh may be wiser.
• DIY for experienced enthusiasts: Requires press, pullers, service manual, and precision measuring tools—mistakes are costly.

These choices balance cost, downtime, and risk. For high-mileage or high-power cars, a rebuilt/reman unit often offers the best long-term value.

Time and Process Overview

Understanding the workflow helps set expectations for scheduling and labor hours.

1. Diagnose: Road test, check clutch operation, scan for related faults if applicable.
2. Remove transmission: May require subframe drop, exhaust/axle removal, and support of engine.
3. Disassemble: Split the case, inspect synchros, hubs/sleeves, forks, bearings, and gears.
4. Replace parts: Fit new rings and any worn components; replace bearings and seals as prudent.
5. Reassemble and set clearances: Torque specs, endplay checks, and sealant application.
6. Reinstall and fill: Refit transmission, align linkage, and fill with specified fluid.
7. Test drive and verify: Ensure smooth engagement across gears under various loads.

Shop time can range from a day to several days, depending on parts availability and vehicle complexity.

Example Cost Scenarios

The following examples illustrate how different vehicles and findings change the bottom line.

• FWD compact (single 2nd-gear synchro, independent shop): 10–14 labor hours + parts = $1,200–$2,000
• RWD sports car (2nd–3rd synchros + hub/sleeve, dealer rates): 16–20 hours + parts = $2,200–$3,800
• AWD performance model (multiple synchros, bearings/seals, complex R&R): 18–24 hours + parts = $3,000–$5,500
• Used transmission swap (average sedan): Unit $900 + install/fluids $900 = ~$1,800

These are typical, not guarantees. A clean teardown with minimal collateral wear can land below these figures; damaged gears or hard-to-source parts can push higher.

Quick FAQs

Common questions from owners weighing repair options.

• Is it safe to drive with a bad synchro? You may limp along by rev-matching, but continued grinding risks gear and hub damage—costs can climb fast.
• Will new fluid fix a failed synchro? It can improve marginal cases but won’t restore a worn or chipped ring.
• Do automatics have synchros? No. Automatics and CVTs use clutch packs/bands or pulleys, not synchros.
• Why does 2nd gear fail most often? High torque at low road speeds and frequent use make 2nd particularly stressed.

If in doubt, get a second opinion and ask for an inspection report with photos of any worn components.

Summary

Replacing a manual-transmission synchro typically costs $1,000–$2,500 for a single gear and $1,500–$4,000 for broader work, driven primarily by labor and the extent of internal wear. Verify that the clutch, linkage, and fluid are correct before committing. Depending on your car and goals, a used, rebuilt, or reman transmission can be a cost-effective alternative with clearer warranty coverage.

Can synchros be repaired?

If you are experiencing difficulty with your synchros, let one of our experienced technicians take a look. Sometimes, a fluid change or cleaning additive will solve the problem, freeing up a malfunctioning synchronizer, or the synchro can be replaced altogether.

How much does synchro replacement cost?

Synchro replacement cost is highly variable, but typically ranges from $2,000 to $3,500 or more, including labor and parts for a full rebuild, though a single synchro replacement for a specialized part could cost around $200-$400 in labor after the transmission is out for other work. The primary costs are the labor to remove and disassemble the transmission and the price of the synchro rings themselves, which can be expensive and difficult to source, especially for specialized performance transmissions. 
Factors influencing cost

• Labor to remove the transmission: This is the most significant cost, as the transmission must be removed to access and replace the synchros. 
• Parts costs: Synchro rings can be expensive, and the price varies depending on the car model and whether standard or performance/carbon synchros are used. 
• Scope of work: You may choose to have more work done during the transmission overhaul, such as a full rebuild or replacement of other components, which increases the overall cost. 
• Vehicle and transmission type: The complexity of the transmission and the availability of parts will impact the cost. 

When to consider synchro replacement

• Grinding gears: Worn-out synchros typically cause gears to grind when shifting, a problem that often worsens over time. 
• Transmission jumping out of gear: In some cases, bad synchros can cause the transmission to jump out of gear after it’s engaged. 
• During other major work: It makes economic sense to replace synchros when the transmission is already removed for other work, such as a clutch replacement. 

Alternatives to replacement

• Transmission fluid change: Opens in new tabSometimes, a different transmission fluid or a cleaning additive can resolve issues with malfunctioning synchros by freeing them up. 
• Transmission replacement: Opens in new tabDepending on the cost of the synchro repair, purchasing a new transmission may be a more cost-effective option. 

What do worn out synchros feel like?

This can manifest as a stiff or grinding sensation when engaging the clutch or moving the gear lever. If you notice resistance or the gears not engaging smoothly, it could be a sign of worn synchros, clutch problems, or a failing gearbox.

What happens when synchros go bad?

When synchronizers (synchros) go bad in a manual transmission, you’ll typically experience a grinding or crunching noise when shifting gears, hard shifting or difficulty getting into gear, and gear “popping out” while driving. These issues occur because the worn synchros can’t properly match the speed of the gears, leading to a poor engagement and preventing the gear from staying engaged. If left unaddressed, this can lead to further damage to the gears and may eventually require a transmission rebuild.
 
Symptoms of Bad Synchros

• Grinding or crunching sounds: This is the most common sign and happens when the synchro fails to synchronize the speeds of the gears, causing them to grind together. 
• Hard or stiff shifting: You might feel resistance or stiffness in the gear lever as you try to move it into gear. 
• Gears not engaging: The transmission may refuse to go into a particular gear, or it might feel “notchy”. 
• Gear popping out: In some cases, a gear that you’ve engaged might pop back out of place, especially when accelerating or decelerating. 
• Whirring or humming noise: A whirring sound specifically when a particular gear is engaged can also indicate a failing synchro. 

Why Synchros Go Bad

• Wear and tear: Over time, the friction surfaces of the synchros wear down, reducing their ability to synchronize gears. 
• Poor lubrication: Incorrect or dirty transmission fluid can accelerate wear and hinder the synchros’ function. 
• Abusive driving: Aggressive or rapid shifting, especially without proper rev-matching, puts extra stress on the synchros. 
• Clutch issues: A failing or misadjusted clutch can prevent the transmission from fully disengaging, which can damage the synchros. 

Dangers of Driving with Bad Synchros 

• Damaged transmission gears: Continued grinding can cause permanent damage to the gear teeth and other components.
• More severe failures: A failing synchro can lead to more significant transmission problems, potentially requiring costly repairs or a full rebuild.