As with any product or service, the cost of repairing a crankshaft will greatly depend on the region in which you reside. Are there many machine shops around? If so, this competition tends to drive down prices and the consumer realizes lower repair costs. However, if there are few automotive machine shops around, the cost to weld or grind a crankshaft will likely be higher. Setting local market conditions aside, which do influence labor costs, let’s look at some of the prices you can expect to pay when taking your crankshaft to an automotive machine shop for repair.
To understand how pricing crankshaft repairs are billed, it is important that you understand that most automotive machinists have a procedure that they follow to perform repairs. While grinding a crankshaft may have a flat fee, its current condition directly impacts the customer’s total out of pocket cost. For example, no automotive machinist wants to machine a dirty crankshaft in a $50,000.00 crankshaft grinding machine. Before internal engine parts are remanufactured, they must be cleaned, inspected and repaired in a sequence that matches the damage that must be repaired.
Dirty crankshafts are most often cleaned in a hot tank that contains a caustic soda chemical solution to remove grease and oil. This process, which is also often mistakenly called an acid dip, is quite effective when used in conjunction with an agitator. The agitator helps to move the solution around a crankshaft’s counterweights, into the oil galley holes and around the journals. In most cases the fee to “dip” a crankshaft in a hot tank is approximately $30.00.
Crankshafts that are rusty, from being exposed to the weather during storage, are often cleaned with a bake and blast process. Baking a crankshaft allows all the grease and oil to harden, which then is blasted off with very small steel shot peen pellets. Cast iron cleaned with this process often looks like aluminum when completely cleaned. The cost to bake and blast a crankshaft is approximately $100.00.
Many automotive machine shops that grind crankshafts do not have baking and blasting capabilities, so they often rely on glass beading crankshafts that are rusty. To glass bead a crankshaft, it must first be free from dirt, grease and oil so that the glass particles do not stick to the crankshaft being cleaned. Many people erroneously refer to glass beading as sand blasting, although both processes use compressed air and particles to act as an abrasive. The cost to glass bead a crankshaft is approximately $50.00, but also may be combined with hot tanking for a total cleaning fee of $80.00.
When a crankshaft is to be ground, it is first inspected with a micrometer to measure the main and rod journals. If the machinist suspects the crankshaft is bent, they will use a pedestal base dial caliper to measure the runout of the crankshaft’s main journals to determine how much it is bent. Most automotive machine shops do not charge separately to inspect a crankshaft that is to be ground. However, if on inspection the crankshaft is determined to be beyond repair, the bill may cost approximately $40.00 for checking the crankshaft for straightness and the journals for size.
Crankshafts that are slightly bent can often be straightened and are normally billed at an hourly rate. For example, if your shop’s labor rate is $80.00 per hour, a crankshaft that takes fifteen minutes to straighten will cost $20.00. Most passenger car crankshafts can be straightened within fifteen minutes, but large industrial crankshafts often take longer to straighten because of a larger journal radii.
When extreme damage to a crankshaft must be repaired, it may need a thrust or journal to be welded. Welding a single journal or thrust can cost approximately $90.00, and this process must be performed before the crankshaft receives its finish grind. Most automotive machine shops include any straightening and the rough grind needed to perform this operation as part of the total cost of the weld.
Grinding a crankshaft does vary slightly for passenger cars. For example, a V6 crankshaft has more rod journals to grind than a V8. Generally speaking, it costs approximately $130.00 to grind a passenger car crankshaft and considerably more for industrial crankshafts. The reason why industrial crankshafts cost more to grind is that a special wheel often must be used that is better suited to machine large diameter journals and the significantly larger radii.
The fees assessed for polishing and chamfering a crankshaft are often bundled into the cost of the grind itself. The reason for this is that the grinding process does not leave a suitable finish for the engine bearings, and it is customary for most automotive machine shops to include the cost of this process in all crankshafts that they grind. However, some crankshafts that are being reused are in good condition and do not require grinding. When polishing is the only labor operation being performed on the crankshaft’s journals, the fee normally does not exceed $50.00.
Now that you have a better understanding of what it may cost to repair your crankshaft, it is always wise to receive an estimate from your automotive machine shop before they perform any work. Additional labor operations not covered in detail on this page may include repairing a damaged keyway, using a helicoil insert to fix a damaged flexplate bolt hole, balancing and other issues which are not so commonly seen in your average crankshafts. Obtaining an estimate first allows you, the customer, to be fully informed of what the machinist will do to correct the defects in your crankshaft and what the expected total cost will be upon completion.