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Crankshaft repair at Route 66 Auto Repair in Upland starts when a bearing has failed and the crankshaft journals, the polished surfaces the bearings ride on, may be damaged. The usual cause is oil starvation. We measure every journal, show you the readings, and explain whether the crank can be restored, must be replaced, or whether the engine as a whole needs a different plan. Your written estimate shows every step.
What damages a crankshaft?
- Low oil level or a failed oil pump starving the bearings
- A spun bearing that turned in its bore and scored the journal
- Coolant or fuel diluting the oil
- Debris circulating after a previous failure
- Very rarely, a crack from a severe mechanical event
How do we assess the crankshaft?
The first sign is usually a deep knock with low oil pressure. We confirm with a mechanical oil pressure gauge and cut open the oil filter to look for bearing material. If the engine must come apart, each journal is measured with a micrometer for diameter, out-of-round and taper, and inspected for scoring and heat discoloration.
Light marks may clean up with crankshaft polishing. Deeper damage means grinding to an undersize with matching bearings, or a replacement crank. Bearing work itself is covered on engine bearing replacement. If the block or rods also suffered, the engine rebuilding comparison may fit better.
Our crankshaft repair process
Step 1: Confirm bottom-end damage
Oil pressure test, filter inspection and a listen with the stethoscope.
Step 2: Tear down
Remove the oil pan, bearing caps and, when needed, the crankshaft.
Step 3: Measure and photograph
Every journal is measured and the readings are recorded.
Step 4: Choose the path
Polish, grind undersize or replace, with every step on the estimate.
Step 5: Assemble and verify
Bearing clearances are checked, then oil pressure is confirmed at start-up.
What's included in crankshaft repair
Included on the work order
- 01Mechanical oil pressure test
- 02Oil filter inspection for debris
- 03Journal measurements on the repair order
- 04Photos of damaged journals and bearings
- 05New bearings sized to the crankshaft
- 06Oil system flush steps as listed
- 07Start-up oil pressure check and road test
Need-now or need-later?
Need now: call
- Any bottom-end knock with low oil pressure. Do not keep driving.
Need later: book
- Slightly low oil pressure at hot idle with no noise, rechecked soon
How pricing and timing work
Crankshaft work is priced after measurement, because the damage decides the path. Engine removal is often required, and machining or parts lead times can add days. We set a window the board can hold and text you if it moves.
Aftercare
Check the oil level weekly for the first month and keep changes on time. If the oil light flickers at idle, stop and call us.
Frequently asked questions
What does a crankshaft knock sound like?
A deep, heavy knock from the bottom of the engine that gets faster with engine speed and louder under load. It often comes with a low oil pressure light.
Can a damaged crankshaft be saved?
Often, if the journals are within limits for polishing or grinding undersize. Cracked or heavily damaged cranks are replaced. The measurements decide.
Why did my bearing fail?
Low oil, overdue changes, coolant in the oil or a weak oil pump are the usual reasons. We check each before reassembly so the new parts are protected.