How do you replace alternator belt on '91 Honda Civic?

Answer 1

The answer for this question is very similar to the question for replacing the alternator. It can also be used to understand how to replace the Power Steering belt and the a/c compressor belt (as their removal is necessary for replacing the inmost belt- the alternator belt). This answer assumes that you understand basic terminology and have an appropriate selection of tools (metric sockets and combination wrenches, screwdrivers, lug wrench, jack and stand, etc) and replacement parts (i.e. the new belt). Consider having a replacement power steering belt and a/c compressor belt on hand if the old ones need replacing when you inspect them- it's easy to do at this point and hard later. 1. Using a frame mount jack point and jackstand (for safety), remove the driver's side wheel. 2. Remove the plastic fairing at the front end of the wheel well by unscrewing the plastic screws *Note, for the next steps, you need to understand that the devices that run off belts from the crankshaft pulley use a common method for mounting- the whole device is mounted at 2 points- a pivot point along the back that allows the whole device to arc up and down- to loosen or tighten the belt- and a clamp nut on a curving slide point. Think like an old style circle drawing compass- the hinge at the top is the main mount point and the curving slide point is a "clamp" to keep the arc the same (and keep the belt tight). 3. Find the pivot nut and "adjustment slide clamping nut" for the top front device (I think it's the power steering booster). The pivot nut is on the outboard side of the device and the adjustment slide bolt is on the inboard side just below it. I think they are both 12mm. Loosen them to "finger loose" but don't remove them. The device should tilt down and the belt should slip off easily. 4. Find the pivot nut and slide clamp nut for the alternator and loosen them to finger tight. I think they're both 12mm too. 5. Crawl under the car and loosen the pivot nut for the adjustable idler that holds the power steering belt tight. It's up in the middle in between the crankshaft pulley and the compressor. The compressor is not movable, but the idler is. 6. This is important! Loosen the clamp nut (14mm) for the idler- it is the nut on the idler pulley. It's difficult to loosen without a long box end wrench, but it can be done with a short wrench and a breaker bar. It's too close to the side to fit a socket wrench in there. Then, climb out from under the car. 7. Using 10mm socket and long extension, turn the idler tension screw (you'll see its head just aft of the power steering booster) to loosen the a/c compresser belt. I'm pretty sure you turn it counterclockwise to loosen, but check to see if the belt is getting looser, and if not, go the other way. Leave it there on the nut if you can, you'll need it to replace the belt. 8. Crawl under the car and slip off the A/C compressor belt and the alternator belt. Crawl out and inspect all belts carefully for unusual wear or cracks. Replace a suspicious belt if in doubt- they're cheap and now's the time to do it. 9. Loop the new alternator belt over the alternator pulley and the power steering belt over its pulley. 10. Grab the A/C compressor belt and go back under the car. Position the alternator belt FIRST- important! It rides at the inmost point of the crankshaft pulley. Make sure it's aligned well or your belt will get chewed up. 11. Position the a/c compressor belt- loop it over the idler, then the compressor pulley, last over the crankshaft pulley. 12. Slip the power steering booster belt over the crankshaft pulley LAST. 13. Get out from under the car. At the back of the compartment, tension the alternator belt using a prybar or heavy screwdriver to pull the alternator away from the block. It doesn't take too much force. Use a good heavy piece of the alternator and block for this- if you guess wrong and break your alternator it's back to the store. Tighten the clamp nut (12mm) moderately. Check the tension by pressing moderately on the belt- it should have about 1/2" of "give" at the center of the span. Too tight and it will wear prematurely, too loose and it will squeal. Check an appropriate shop manual for exact specs. Once you have the belt tension right, tighten the clamp nut 1st, then the pivot nut. Check the position of the belt on the pulleys carefully to make sure the alignment is good after tightening. 14. Do the same with the power steering booster belt. 15. Use the 10mm socket + extension you left in place and turn clockwise to tighten the a/c compressor belt by moving the idler. Once tension is set, tighten the clamp bolt (14mm) on the idler pulley. Remove your 10mm socket and extension. 16. Make one last inspection of the belts and pulleys. Remove any tools in the engine compartment. 17. If your jackstand is pretty sturdy, you can crank over the engine at this point to see how the belts run. It won't hurt the engine to run with no driver's side wheel. If your belts look like they're running smoothly and not making any odd noises, you're in business! Turn off the engine when you're done making the check. 18. Replace the plastic fairing in the wheel well. 19. Replace the wheel and tighten the lugnuts "mostly tight". 20. Remove your jackstand and any other tools under the car. Lower the car and tighten the lugnuts all the rest of the way. 21. Close the hood and pat yourself on the back. You've just done a $100 repair!