A/C Tensioner (Idler Pulley) Replacement
No stranger to these pages, Mikebai1990 contributes another great article for our club's website. Back in October '06, he showed us how to drain the transmission fluid and replace the transmission strainer. This month, he shows us how to replace a worn (usually seized) A/C belt tensioner (AKA Idler Pulley).
Take it away, Mike...
A worn idler pulley seems to be a fairly common problem in our Vigors nowadays. The idler pulley, also known as the A/C belt tensioner, is essentially a ball-bearing that can be adjusted to maintain the proper tension in the belt. This pulley is packed with a high-temp grease, and over time this grease wears out, thus wearing out the metal bearings as well. The result is anything from whining to a grumbling noise that is audible when driving. The following will illustrate how to replace this idler pulley. There are two ways to do this. You can either buy a new bearing to press into the pulley, or you can order the pulley as a whole, OEM. Replacing the bearing will be significantly less expensive, but you will need the pressing equipment (a bench vice and some sockets).
According to Docsteen: "The a/c tensioner pulley bearing can be replaced without buying the pulley. Do a search on eBay for 6203RS and you'll get it. It's 17×40 mm."
My replacement was a full OEM pulley replacement.
I have numbered each part on my pictures for easier reference in the procedures.
1. I had the radiator out while I was performing this replacement, so it was very easy to reach in and remove the pulley. I'm pretty sure that there is enough clearance to perform the replacement with the radiator installed, but it may be tricky. Others may be able to clarify. (Editor's note: Bob01721 was able to replace his without removing the radiator. "Mike's right. Not a problem. There's plenty of room.")
2. When removing the following two items, you may need to spray some penetrator to break the bolts loose. Mine came off with ease, because the belts had been changed a year or two ago. Remove the center nut (#1) that holds the idler pulley (see photo). Take out the cover, nut, and washer.
3. Loosen the tension on the belt with the adjusting bolt (#2). A little counterintuitive, but you have to turn the bolt right to loosen the tension. Just make sure that the belt is getting looser and looser. When the belt is loose enough you will be able to remove the idler pulley (#3).
4. You can spin the idler pulley and see whether there are any noticeable problems. I noticed that my old bearing was significantly looser than the new one, and was making sounds when I turned it. The new bearing on the other hand was tighter and did not make any sounds.
5. Take the new pulley and fit it into position, making sure the belt is aligned properly with the grooves. Put the center nut back on and make somewhat snug so that the pulley won't fall off. Do not fully tighten.
6. Tighten the adjuster bolt to the specified tension. The Acura Vigor Service Manual (Page 22-26) says that and old belt (ran for more than 5 minutes) should have a 6mm - 9mm (or .24" - .35") movement when a 100N or 22lbs force is applied to the belt.
7. Fully tighten to the center nut to a torque of 45 N-m or 32.5 lb-ft.
8. And.. YOU'RE DONE!
Unfortunately I haven't gotten the car running yet because the radiator is still enroute, but I will update with whether my grumbling noise has disappeared after this replacement!
You've done it again, Mike. Thanks!