Using o reilly belts for a rush job - PeachParts Mercedes-Benz Forum

studjuice · #1 03-10-2013, 09:07 PM

Upon inspecting my car after finding out my alternator isn't working I've found that one of my alternator belts is gone, the other is missing teeth and cracked, power steering belt is cracked, and the ac belt is gone. I was already planning on replacing the belts but wasn't planning it to go down like this. Now since I need to replace them rather quickly I gotta use some belts from O Reilly's (only auto parts store around me). After reading up on the forum there's a general consensus that their belts are the wrong sizes, and looking at their sizes online compared to peachparts sizes it's pretty obvious why they don't fit right.

So by looking up the part numbers I looked up the right sizes (or as close as possible) and here's what I found. NOTE: Since I have the double pulley alternator the width is thinner than the single pulley ones.

Alternator/Water Pump belt: Masterpro #7400, 10x1034. Stock is 10x1035. O Reilly's recommended belt was 10x1042.

Power Steering belt: Masterpro #9447, 13x1145. Stock is 13x1145. O Reilly's recommended belt was 13x1160.

AC belt: Masterpro #9360, 13x930. Stock is 13x925. O Reilly's recommended belt was 13x937.

I'll be picking these up tomorrow to do the job and I'll report back on how well they work and stuff if it goes well. I'm hoping that finding the right sizes will give me a better experience, though I'm not expecting these to really compete with contitech. They will probably stretch a lot. But for the sake of science, I plan to test out how well these work out before replacing them with contitech (which I'll still get). Any advice before tomorrow is welcome of course.

Volker · #2 03-10-2013, 10:25 PM

A belt is just a belt, your length is not important as you have lots of adjustment... I mean 1145 versus 1160... it's like 1/2 inch on the length, the difference is 1.3%

What is really important with the twin-belt system is belt that are from a matched set, if you are 1 mm off with them, one will do all the work and the other flops and gets destroyed, this may have happened on yours.

Walkenvol · #3 03-11-2013, 01:37 PM

Quote:

Originally Posted by Volker

A belt is just a belt

I've not found this to be the case with my belt history as there appears to be a wide range of quality between different belts. Some stretch more than others and required regular tightening. I've also had some noisy belts that quieted down when replaced with a better known brand such as Gates (although they probably have different levels of quality in their product line also).

Orv · #4 03-11-2013, 01:44 PM

I recently replaced all my accessory belts with ones from O'Reilly -- I forget the brand name, but of the two they offered it was the more expensive one. They fit fine and haven't stretched so far.

Then my suspension hose blew and drenched them with hydraulic fluid, but that's another story.

They started to chirp a little bit after that.

studjuice · #5 03-11-2013, 01:52 PM

the ones I've listed at the cheaper ones. The expensive ones are $20 per belt! so i'm getting the cheap ones that are around $5 per belt and later I'll replace them with oem ones which are around $8. works out to around the same price

vstech · #6 03-11-2013, 02:06 PM

keep this in mind...
the only belts you'll have problems with are the alternator/water pump dual belt.
of course, EVERY other belt has to come off to change them...

Orv · #7 03-11-2013, 02:08 PM

Quote:

Originally Posted by vstech

keep this in mind...
the only belts you'll have problems with are the alternator/water pump dual belt.
of course, EVERY other belt has to come off to change them...

Yup. The reason I replaced them all was I was changing the alternator and wanted new belts for it...and since all the other ones had to come off, too...

I did leave out the A/C belt. The A/C hasn't worked in years.

studjuice · #8 03-12-2013, 04:44 PM

Finished the job. The alternator belt wasn't too difficult to get on, I hand turned it and got it it on. The ac belt I had trouble with because it was difficult to get it tensioned out all the way. I'm sure there's something else I could have done but there was too much oil crud for me to figure it out, so I got it half way loosened and bump started the belt on. That was easy, only took one try. Finally the power steering belt was tight to put on (don't think I loosened that one all the way either) so I bump started it on, and that only took one try.

All in all, this was fairly easy. Wouldn't have taken so long if my engine was clean, and if I had noticed that I put the alternator fan on backwards and had to redo that job twice. There was no squeaking at all on my first start after getting the belts on, so I think that's good. It's also amazing to not hear a loud screech when I rev the engine, sounds so much better.

Haven't taken it on a drive yet, still need to do an oil change. But I tested the voltage and it's nice to see the alternator working again. Later this year I'll get some refrigerant in the ac and who knows, maybe it will work since it was missing a belt.