How much does it cost to repair a hydrostatic transmission on a lawn mower?
Hydrostatic transmission repairs are typically a riding-mower cost category; the Craftsman 917376451 is a walk-behind mower and normally uses a belt-and-pulley self-propel drive instead of a hydrostatic transmission. For hydrostatic units, total repair cost commonly ranges from a few hundred dollars for minor service to $1,300+ for the transmission itself, and up to about $2,500 for a full replacement with labor.
What you likely have on Craftsman 917376451
Before pricing a “hydrostatic” repair, confirm the drive type in the 917376451 owner’s manual. Most walk-behind self-propelled mowers use a mechanical drive system (cable, belt, pulleys, wheels), so the fix is often a cable, wheel, or pulley rather than a transmission.
Common self-propel drive parts that affect movement:
- Drive control cable (stretched, kinked, or broken)
- Drive pulley (worn groove, debris jam)
- Drive wheel (worn teeth or hub)
- Return spring (weak or disconnected)
- Blade and deck area packed with grass (adds drag)
Typical hydrostatic transmission repair cost ranges
Hydrostatic systems are most common on riding mowers and zero-turns. Pricing depends on whether you are doing a fluid service, replacing a drive belt, or replacing the transaxle.
| Repair scenario | Typical cost range (parts + labor) | Notes |
|---|---|---|
| Basic diagnosis and adjustment | $75 to $200 | Shop minimums vary |
| Fluid and filter service (if serviceable) | $150 to $400 | Some units are sealed |
| Drive belt/idler related repair | $150 to $500 | Often mistaken for “bad hydro” |
| Hydrostatic unit/transaxle replacement | $900 to $2,500 | Parts cost can be $1,300+ |
If your walk-behind mower “won’t move”, check these first
These checks often solve the problem faster than chasing a transmission issue:
- Verify the drive control cable has proper tension and isn’t binding; consider replacing the lawn mower drive control cable 532407816.
- Inspect the drive pulley for wear; a damaged pulley can slip under load.
- Check the drive wheels for worn engagement surfaces; replace if the tread or hub is stripped.
- Clean packed grass from under the deck; heavy buildup increases rolling resistance.
- Confirm the engine is running smoothly; poor power can feel like a drive failure.
Why it matters
Hydrostatic replacement is one of the highest-cost mower repairs. Identifying whether you have a hydrostatic system (riding mower) or a mechanical self-propel drive (walk-behind) prevents unnecessary parts purchases and gets you back to mowing sooner.
Last updated: January 2026
Should I use 87 or 91 gas for lawn mower?
For the Craftsman 917376451 gas walk-behind mower, 87 octane (regular unleaded) is the right choice for normal operation. Higher octane (like 91) does not add power in small mower engines; using fresh fuel and the correct oil level matters far more for starting, smooth running, and engine life. See the fuel and operation guidance in the 917376451 owner's manual.
What to use (and what to avoid)
- Use fresh, clean regular unleaded gasoline (87 octane).
- Avoid old gas (stale fuel is a top cause of hard starting and surging).
- Avoid fuel contaminated with water or dirt (it can clog carburetor jets).
- If your mower will sit, use a fuel stabilizer and follow storage steps.
- Do not “upgrade” octane to fix running issues; address the real cause (fuel quality, air filter, spark plug, carburetor).
Quick comparison
| Fuel choice | Best for | What you will notice |
|---|---|---|
| 87 octane (regular) | Everyday mowing | Normal power and reliable operation |
| 91 octane (premium) | Not needed for typical mower engines | Usually no performance benefit |
Why it matters
Using the correct fuel keeps the engine running cooler and cleaner over time, but freshness is the biggest factor. The manual also emphasizes routine care that directly affects engine life, such as keeping the mower clean and preventing debris buildup that can make the engine run hotter. Review the maintenance and safety notes in the 917376451 owner's manual.
If you are having fuel-related symptoms
If the mower is hard to start, surges, or stalls, these checks fix most issues:
- Drain old fuel and refill with fresh 87 octane.
- Check the oil level before starting (many mowers ship without oil when new).
- Inspect and service the air filter.
- Inspect the spark plug and replace if fouled.
- Clean grass and debris buildup from the deck and engine area.
Last updated: January 2026
What model number is a Craftsman 6.75 lawn mower?
A Craftsman “6.75” walk-behind mower is not identified by engine size alone; you need the full mower model number from the ID label. For the Craftsman mower covered by our documentation, the model number is 917.376451; confirm it in the 917376451 owner's manual.
How to identify your exact Craftsman mower model
Use the mower’s product ID label, not the engine cover decal.
- Look for a label that says Model No.
- Copy the number exactly as printed (digits and punctuation)
- Record the serial number too if it’s listed
- Use the mower model number for parts diagrams and ordering
- If you also see an engine model/type/code, keep that for engine-specific tune-up parts
Why “6.75” does not equal one model number
“6.75” is commonly a power rating or marketing description used across many Craftsman walk-behind mowers. Craftsman built multiple decks, handle setups, and drive systems that can share similar engine ratings, so the mower’s model number is the only reliable identifier.
Quick ID comparison
| Marking you see | What it usually identifies | Best use |
|---|---|---|
| 6.75 (or similar HP/torque rating) | General engine power class | Rough comparison only |
| 917.XXXXXX | Craftsman mower model | Correct parts lookup |
| Engine model/type/code | Specific engine build | Engine tune-up parts |
Parts examples for model 917.376451
Once you confirm the model number, match parts by diagram key and description.
- Lawn mower mulching blade 532406707 for blade replacement
- Lawn mower drive control cable 532407816 for self-propel drive control issues
- Lawn mower grass bag assembly 583327401 for bagging and collection
Why it matters
Using the correct mower model number prevents ordering the wrong blade, drive parts, wheels, or handle hardware, even when two mowers have similar engine ratings.
Last updated: January 2026





