OK... I have a 96 Honda Civic CX. Not sure if it's relevant, but based on the diagrams in my service manual, I do NOT have a B16A2 type engine. Alternator was bad so I changed it. While I was in there I noticed the P/S pump belt was SUPER frayed and cracked so thought I'd change that as well. Went to autozone, and gave them the year/make/model of the car, and they sold me this belt:

Duralast Multi-V belt
4PK0845

I went home and took off my power steering pump belt, and the numbers didn't add up. Here's the info from my belt:

4PK820 part no: 38920-P2A-003

It's my understanding that it's the 3 digit number after the "PK" which is significant in this case and tells how long the belt is, and 820 seemed like a big difference from 845. When I googled the part number off the old belt I took off, I was surprised to find it was showing up as an A/C compressor belt! Example, here's the first hit on google when I plug in that part number I looked up on rockauto.com, and sure enough for a 96 honda civic, it showed this info for the P/S belt, which is the size that autozone sold me:

DAYCO Part # 5040333DR {#333K4, 4PVK0845} Power Steering
http://www.rockauto.com/catalog/x,ca...2BDrive%2BBelt

Is it possible someone could have put an A/C compressor belt instead of a P/S belt by mistake? Should I take off the A/C belt and see if there's a P/S pump belt on it?? Does it even matter? I will also say it was wiked hard to get that old belt off as it was so tight on there, even once I'd loosened the power steering pump and bolt tensioner. In fact I almost had to take the power steering pump all the way off. If the belt size was wrong on my car though wouldn't it have broken the pulley or the power steering pump or something? (that's the belt that's been on there since I got the car 5 years ago, I've driven the car from coast to coast) I will say, the engine in that car is not the original, it was swapped. But I don't know how to find out what year/make/model the other engine came from. I was told it's from the same (a 96 honda civic) but maybe that's a lie. Is there a way to find out?

 

Now that I had some daylight, went outside and looked and sure enough, the A/C compressor has belt size 845 on it, instead of size 820. It seems someone must have switched the belts. woah. Could this have been causing any issues with my car? It at least might explain some of the squealing noises. But considering I drove it like this for 5 years, I'm just curious. I don't know anything about belts.

 

Slight difference in length doesn't affect anything, as long as the pulleys can adjust far enough to make the belt tight.

The "4" is the number of ridges on the inside of the belt, and that is important that it match the number of grooves in the pulleys.

 

Oh great I am relieved to hear this. the pulleys all seem to be in fine shape, no squeaking or wobbling or anything. So does that mean since the belt that's no the A/C compressor is still in good shape, it's really not paramount that I switch it just to put the right size on?

 

If you get a horrible squealing noise that gets worse when you turn your A/C on that means that the bearings are shot in your compressor, and it's bad. Just check for 1/4 deflection you don't want the drive belts too tight either. In the future when you change use brake cleaner on the pulleys to get rid of any glazing for future chirps or squeaks, and I've found gator belts to be more precise with fitment.