The Right Tools at the Right Time
By Larry Carley, Technical EditorThe toughest part about changing a timing belt on most engines is just getting to the belt. The timing belt is sealed inside a protective cover on the front of the engine. Replacing it typically requires removing everything on the front of the engine that obstructs the timing cover. This includes the serpentine belt and/or V-belts, idler and tensioner pulleys, often the crankshaft pulley, and removing or repositioning any belt-driven accessories such as the water pump, alternator, A/C compressor and/or power steering pump that may be in the way.
- Ordinary hand tools to remove the timing cover, brackets and engine-mounted accessories.
- A serpentine belt removal tool to loosen the automatic belt tensioner — this is a must on tight-fitting transverse-mounted engines.
- A floor jack, engine puller or engine support bar to support a transverse-mounted engine if the motor mount must be removed.
- A belt tension gauge may be required on some applications to set the tension on the timing belt.
- A torque wrench for tightening critical fasteners (the belt tensioner, idler pulleys, camshaft pulley bolts and/or crankshaft pulley bolt).
- A universal gear puller or special OEM crankshaft pulley removal tool if pulling the crank pulley is necessary to replace the belt.
- Special camshaft positioning tools (or a bolt or pins) may be required on some dual overhead cam engines to hold the cams in place while the belt is replaced (see the OEM tool list that follows).
- A special timing belt tensioner adjusting tool may be required on some engines (again, see the OEM tool list that follows) to set belt tension.
- A timing belt replacement manual or the OEM service literature to look up the positioning of the timing marks and the belt replacement procedure. The replacement procedure for some belts is not obvious and requires following a step-by-step procedure so that everything is installed correctly and lines up. Considering how much labor is required to replace some timing belts, it’s not a job you want to do over.
Special OEM Timing Belt Tools
The following is a sample of some of the special OEM tools that may be required to replace a timing belt. In many instances, you can use a universal gear puller in place of the factory crank pulley puller, or substitute another tool for the recommended factory tool, but it’s always easier with the OEM tool or an equivalent aftermarket tool that has been designed for the same purpose. For cam positioning tools, you may even be able to fabricate your own tool using the OEM tool as a guide. Audi 2.8L V6 (1992-’94) — Requires camshaft holding tool 3243 and crankshaft holding tool 3242. Chevrolet 3.4L V6 DOHC (1991-’94) — Requires two camshaft timing
clamps J38613-A.
- Loosen the tensioner pulley bolt.
- Using tool MD998752 and a torque wrench, turn the pulley clockwise with 22-24 in.-lbs., hold the pulley and torque the tensioner bolt to 31-40 ft.-lbs.
- Remove the rubber plug from the engine mount bracket and screw in tool MD998738 until it moves in the automatic tensioner pushrod.
- Remove the 0.055” rod from the tensioner body.
- Remove tool MD998738, turn crankshaft clockwise two revolutions and wait 15 minutes.
- Measure the pushrod protrusion. It should be 0.15” to 0.18”.
- If it is not, repeat the tensioning procedure.
Chrysler/Dodge/Plymouth 2.2L and 2.5L (1981-’95) — Requires tensioner wrench C-4703.