On this page
The transmission case is the metal housing that holds every internal part, and Route 66 Auto Repair in Upland assesses and repairs cases that are cracked, holed or have damaged threads or mounting ears. Damage usually comes from road debris, a broken internal part or a failed mount. Our ASE-certified technicians tell you honestly whether the case can be repaired or should be replaced, and your written estimate shows every step.
What are signs of transmission case damage?
- A fast leak from a crack or hole in the housing
- A visible impact mark from road debris or a curb
- A stripped bolt hole where the pan or a cover will not tighten
- A broken mounting ear or bellhousing bolt boss
- Internal noise followed by a sudden leak
- Leaking at a case seam or cover
How do we decide between repair and replacement?
We clean the case and inspect the damage. Stripped threads can often be repaired with thread inserts. Some small cracks in non-pressure areas can be repaired. A hole caused by a broken internal part means the inside needs inspection too, and often the case repair is the smaller part of the job.
Cracks near bearing bores or pressure passages are riskier to repair. In those cases, a replacement case or a replacement transmission may be the honest answer, and we explain the tradeoffs. We also look for the cause, such as a failed transmission mount or a stretched chain on 4WD units. Bigger decisions tie into our transmission repair page.
Our case repair process
Step 1: Clean and inspect
The damage is cleaned, measured and photographed.
Step 2: Find the cause
We check mounts, internal parts and debris damage.
Step 3: Explain the options
You get a written estimate that compares repair and replacement where both apply.
Step 4: Repair, refill and test
The approved repair is done, fluid is filled and the unit is road-tested and rechecked for leaks.
What's included in case repair
Included on the work order
- 01Damage cleaning and photos
- 02Cause check for mounts and internal parts
- 03Written repair versus replacement comparison
- 04Approved thread, crack or component repair
- 05Fresh fluid to the specified level
- 06Leak check and road test
Can case damage wait?
Need now: call
- Any crack that leaks steadily
- A hole from an internal failure
- A broken mounting point
Need later: book
- A dry cosmetic scrape
- A single stripped cover bolt with a temporary seal holding
How case repair is priced
Price depends on the location and type of damage and whether the transmission must come out. Thread repair can be modest. Internal damage changes the scope completely, and we stop and call you before going further. The diagnostic fee is stated at the counter and applies to approved related repair.
After a case repair
Check for leaks for a couple of weeks. If you drive on rough roads or off-road, consider a skid plate to protect the case. Any leak from the repair area comes back to the front of our line.


Frequently asked questions
Can a cracked transmission case be fixed?
Sometimes, depending on where the crack is and what caused it. We inspect and tell you honestly if repair makes sense.
What causes a transmission case to crack?
Road debris, hitting a curb or rock, broken internal parts and failed mounts are the common causes.
Is replacing the whole transmission cheaper?
Sometimes. When the damage is severe or internal parts are also damaged, replacement may be the better value. Your estimate compares both.
