I just bought a set of belts from Pelican parts for my 300D, after one of the alternator belts snapped and took out the other one and the PS belt.


I noticed that despite chosing the belts listed as OEM Mercedes, that they aren't ribbed. Does anyone know if these are still ok to use? My experience has been that you're supposed to replace like for like, but I don't know if these are still usable. Pelican Parts says they fit, but IDK.

I have used non ribbed belts on my 1985 300D for years with no problems. Just be sure the alternator belts are a matched pair.

∆∆∆ Exactly ∆∆∆ and that the labels line-up exactly on those matched belts...why??? Because it looks better until one slips a little 😀.

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"Rudeness is a weak man's imitation of strength" - Eric Hoffer

Ribbed V belts ( inside usually Gates / outside usually Dayco ) are just so the belt wraps around small pulleys better. I've never done any long terms tests to show if plain or ribbed is any better.

The matched set of belts is a thing of the past, sizing and quality control are much better today.

Belts are made in a big band then cut to width. If you look at the label there is a sequential number showing where in the band the belt came from. In old days this number was used to match pairs since a belt next to any one you pick will be the same diameter. These days, the number is just to track quality.

Another bit, look at the side of the belt and you will see fabric cords.

Quality belts are top cord. This is where the fabric is near the top of the belt. This leads to waste during manufacture because you lose material between the narrow portions of the belts.

Low end belts have a mid cord so the belts can be cut top up, bottom up , top up. This leads to no wasted material and the expense to get rid of it. The problem with a mid cord belts is they don't wrap around pulleys very well leading to early failure.

You'd sure think so. I had a set of Dayco belts for my SL that came from 2 different lot numbers. Both the same part number and made the same year at the same factory. One was just slightly larger than the other and made tensioning impossible. Make sure identical belts from from the same lot.

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Current stable:
1995 E320 149K (Nancy)
1983 500SL 120K (SLoL)

Black Sheep:
1985 524TD 167K (TotalDumpster™)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Every OEM belt I’ve seen from continental or optibelt I recall to be labeled like this:



And ribbed like this:



I don’t recall seeing non ribbed OEM from an MB supplier (or BMW when I had my e30). But may be wrong?

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Current Diesels:
1981 240D (73K)
1982 300CD (169k)
1985 190D (169k)
1991 350SD (113k)
1991 350SD (206k)
1991 300D (228k)
1993 300SD (291k)
1993 300D 2.5T (338k)
1996 Dodge Ram CTD (442k)
1996 Dodge Ram CTD (265k)

Past Diesels:
1983 300D (228K)
1985 300D (233K)

My '82 300D has used nothing but smooth belts (which is how it came from the factory) and seems to be getting along just fine.

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When cryptography is outlawed, bayl bhgynjf jvyy unir cevinpl.

As I understand it, the more important metric is the belt profile, as metric belts have a slightly different sizing and profile than some domestic belts do. End of day, of the accessories al work and there’s no belt noise, slip, etc., I’d say it doesn’t much matter.

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Current Diesels:
1981 240D (73K)
1982 300CD (169k)
1985 190D (169k)
1991 350SD (113k)
1991 350SD (206k)
1991 300D (228k)
1993 300SD (291k)
1993 300D 2.5T (338k)
1996 Dodge Ram CTD (442k)
1996 Dodge Ram CTD (265k)

Past Diesels:
1983 300D (228K)
1985 300D (233K)

THIS ~ metric belts fit properly and so last longer and slip less.....

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-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better

Yep, I should have added that qualifier, same goes if using two different brands of belts.

So, I guess that begs the question of how do you ensure that happens, especially when buying from online?

I think I’ve seen some sold as such, but not always.

__________________
Current Diesels:
1981 240D (73K)
1982 300CD (169k)
1985 190D (169k)
1991 350SD (113k)
1991 350SD (206k)
1991 300D (228k)
1993 300SD (291k)
1993 300D 2.5T (338k)
1996 Dodge Ram CTD (442k)
1996 Dodge Ram CTD (265k)

Past Diesels:
1983 300D (228K)
1985 300D (233K)

I would recommend that you purchase the same quality brand of belts and that they are a matched set. While quality control and manufacturing techniques are greatly improved, there still may be very small differences which will make adjustment difficult.

What is the best source for W123 alternator/water pump belts sold as a "matched set?"

__________________
When cryptography is outlawed, bayl bhgynjf jvyy unir cevinpl.

I have used Dayco and Continental belts over the years with good success.