The timing chain on a Chevrolet 350 engine (also known as the 350 SBC, for small block Chevy) rotates the camshaft in synchronization to the crankshaft rotation. After years of service (or tens of thousands of miles of use) timing chains can stretch. This can affect the performance of the engine. Additionally, the camshaft gear can wear. (Older cam sprockets were made with nylon teeth for quieter operation and would fail, rendering the engine inoperable.) As a do-it-yourself project, the replacement of these parts can take the better part of a single day, so plan accordingly and organize the required tools and parts beforehand.
Things You'll Need
- Assorted sockets/wrenches
- Harmonic balancer puller
- Harmonic balancer installer
- Timing chain/sprocket set
- Timing gasket set
- Engine coolant drain pan
Preparation and Accessory Removal
Order or purchase the correct timing set (chain and two sprockets) and gasket set for the engine model being repaired. Be certain to specify the model year and application of the engine. Also include a small tube of gasket sealer in the purchase. Local parts stores typically have these items in stock and may have balancer puller and installation tools available for rent. You can also order the parts online from parts vendors.
Remove the fan from the water pump. Next, identify and remove all drive belts and accessory fasteners/bolts so you can remove the water pump. These will vary from vehicle to vehicle, but examples might be steering pump, alternator or A/C brackets.
Before you remove the water pump, be certain all of the water from the cooling system has drained completely. (The goal is to avoid getting any coolant in the engine crankcase once you've removed the timing cover.)
Tining Chain Replacement
Loosen and remove the water pump (four bolts attach the water pump to the front of the engine block). Scrape and clean the gasket surfaces of each. Remove any pulleys attached to the harmonic balancer. Remove the balancer bolt and attach the harmonic balancer puller to the front of the balancer and tighten the center bolt to pull the balancer off the crankshaft. Remove several of the front oil pan bolts and loosen the remainder so that the oil pan can be partially lowered away from the timing cover. Remove all timing cover bolts and gently pry the cover away from the engine block. Scrape and clean all gasket surfaces. Remove and replace the front crankshaft seal in the timing cover.
Rotate the engine by hand so that the two timing marks on both sprockets are aligned. Remove the three cam sprocket bolts and slide the cam sprocket off the camshaft. Slip the chain under/off the crank sprocket. Install the new chain and camshaft sprocket, making certain both timing marks are aligned at their closest point. (Tip: Crank sprockets rarely fail or wear. If no damage is visible, you can save time by not replacing it.) Tighten the cam sprocket bolts to 20 pound-feet of torque.
Apply a modest amount of gasket sealer/adhesive to the mating surfaces of the timing cover and engine block. Reinstall the timing cover with 6 pound-feet of torque to each bolt. Apply a small "dab" of silicon sealant at each end of the oil pan seal. Replace/tighten all the oil pan bolts. Apply a small amount of oil or assembly lube to the surface of the front seal and balancer hub, then reinstall the harmonic balancer with the replacement installer/press. (Do not reinstall the balancer with the bolt or a hammer.) Replace the balancer center bolt using 60 pound-feet of torque.
Continue to reinstall all of the components that were previously removed in reverse order. Finally, refill the radiator coolant, start the engine and check for any coolant leaks and repair, if needed.
- Photo Credit Thinkstock/Comstock/Getty Images
How to Check and Replace a Timing Chain in a Chevy Camaro
Many cars are equipped with a timing chain rather than a timing belt. While both drive a vehicle's camshaft, timing chains are...
How to Set the Timing on a 350 Engine
Setting the ignition timing on a 350 engine means you synchronize the rotation of the distributor with the rotation of the crankshaft....
How to Check Timing Chain Wear on a Small Block Chevy
As the timing chain in the small-block Chevy engine wears, it stretches and becomes unable to accurately control valve and ignition timing....
How to Change a Timing Chain on a Chevy
The timing chain on the Chevy S10 requires that it be replaced about every 60,000 to 70,000 miles in order to prevent...
How to Install a Timing Gear in a 350 Chevy Small Block
Chevrolet’s 350 small block engine features two timing gears. Connecting the timing gears is a single chain. The purpose of the gears...
350 Chevy Camshaft Installation
Changing the camshaft on a small block Chevrolet 350 engine is a project that requires methodical disassembly, inspection and reassembly of many...
How to Install Timing Chain on Chevy 454
The timing chain on a Chevy 454, or a 7.4-liter engine only needs to be replaced when you hear it rattling. There...
How do I Read 1968 Corvette 327 SBC Timing Marks?
The 1968 Chevrolet Corvette with the 327 cubic-inch small-block V-8 engine has a timing marker attached to the timing cover on the...
2000 Dodge Intrepid Timing Chain Installation
An engine that is out of time will not run at all, or will run very rough. So, it's very important that...
How to Set Up the Timing on a Chevy 400 Engine
Having your timing set to the proper specification will help to ensure the best performance and gas mileage from your 400-cubic-inch Chevrolet...
Worn Out Chevy Timing Chain Symptoms
Timing chains connect an engine's pistons with the intake and exhaust valves. The intervals of opening and closing are very short --...