How to align the timing belt on a Buick Excelle?
4 Answers
Buick Excelle timing belt alignment method: Align the mark on the camshaft with the notch on the valve cover gasket, and align the mark on the crankshaft timing gear with the mark on the timing cover. To ensure correct assembly (the white marks on the gears should be aligned), it is recommended to use professional tools, especially as the camshaft is prone to misalignment when installing the timing belt. The Buick Excelle is based on General Motors' global platform, with its prototype being a newly developed global mid-size sedan designed and developed primarily by General Motors Daewoo Auto & Technology (GMDAT). In terms of body dimensions, the Buick Excelle measures 4468mm in length, 1765mm in width, and 1469mm in height, with a wheelbase of 2611mm.
I've been repairing Buicks for over a decade, and changing the timing belt on an Excelle requires careful attention. First, remove the engine upper cover and locate the crankshaft pulley. Use professional tools to secure the crankshaft position, bringing the first cylinder piston to top dead center. Then loosen the tensioner pulley bolt and remove the old belt. When installing the new belt, pay close attention to the arrow direction—start by placing it on the crankshaft gear, then onto the two camshaft gears. Special attention must be paid to aligning the camshaft indents with the marked lines, ensuring both sides are parallel. After installing the belt, adjust the tensioner pulley and use a tension gauge to test for a 90-degree twist. Finally, manually rotate the crankshaft two full turns and recheck all alignment marks. Throughout the process, also watch for the balance shaft marks—being off by even one tooth can cause valve interference. This job requires two people to coordinate, as doing it alone is prone to errors. Beginners are advised to seek a repair shop.
Last week, I just replaced the timing belt for my friend's Excelle, with the key being precise alignment. First, disconnect the negative battery terminal, then remove the engine cover and belt guard. Use a dedicated crankshaft positioning pin to lock the flywheel, aligning the small dot on the crankshaft with the gap in the oil pump. The V-shaped mark on the camshaft gear must align with the groove on the cylinder head, ensuring it's perfectly level on both sides. At this point, loosen the tensioner and remove the old belt carefully without touching other components. When installing the new belt, loop it from the bottom up, with the arrow pointing toward the front of the engine. After the belt is in place, tighten the tensioner pulley bolt—the standard is that it should twist 90 degrees with finger force. Before reassembling the guard, manually rotate the crankshaft a few turns to confirm the marks haven't shifted. Also, synchronously check the balance shaft mark; for most Excelle models, there's a small hole near the oil filter that needs alignment. Ensure the full set of tools is ready, including calipers and positioning pins—none should be missing.
The Excelle requires a specific sequence for timing alignment. After removing the cover, secure the crankshaft position and align the mark with the 0-degree line. The timing marks on the two camshaft gears should be parallel, pointing towards the 9 o'clock and 3 o'clock positions. Loosen the tensioner to remove the old belt, then install the new belt following the sequence: crankshaft - camshaft - tensioner pulley. Adjust the tension so that pressing the middle of the belt leaves a 5mm gap. Finally, rotate the crankshaft to double-check the alignment. It is recommended to have this done by a professional shop.
