Alternator belt - help!

1979-1991 280SE, 300SE, 300SEL, 380SE, 380SEL, 380SEC, 420SE, 420SEL, 420SEC, 500SE, 500SEL, 500SEC, 560SEL, 560SEC
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Twigz
Dernburg Wagon
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Region: Western Australia
Location: Albany

Alternator belt - help!

Post by Twigz » Fri 31 Aug, 2018 5:18 pm

My 280SE recently snapped the alternator belt, so I've done the process of changing it, however I've run into a problem. The book at the parts store lists two different sized belts - 11A0965 and 11A0980. I got both. The 965 wouldn't fit on at all, and the 980 still slips even when the alternator is at the end of its adjustment rail. Have I done something wrong, or is it supposed to be a different belt?
1985 280SE - daily driver

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Bartman4800
300 SLR
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Re: Alternator belt - help!

Post by Bartman4800 » Fri 31 Aug, 2018 7:10 pm

With the shortest belt, you might have to take out the adjustment bolt, slip the belt on and reinstall the bolt.

If they have a size in between, that might serve your purpose.

If you lived a bit closer to Rockingham, you could pick one up from me for 5 bucks; I got my hands on 100 different sizes...


Bart
1963 220 Sb Sedan "Kermit" (Australian Assembly)
1960 220 Sb Sedan "Zum Schlachten" (Early German Assembly, with a torsion bar spring for the bonnet) - Stored in Country WA
1981 Subaru Brumby 1.8 with Weber and 5-speed box "little utie" - Sold to another enthusiast!
2006 Ford Focus "daily driver"
2002 VW Passat V6 30V Station Wagon (SOLD - This car into a money pit)
2011 Kia Sportage "Missus commuter Bus"
2002 Mitsubishi Rosa Bus (converting it to a motor home)

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Twigz
Dernburg Wagon
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Re: Alternator belt - help!

Post by Twigz » Sun 16 Sep, 2018 3:36 pm

There's literally no way the 965 will fit, and the 980 squeals. And there's no 11mm belts in between 965 and 980. I've tried everything, but it won't go on.
1985 280SE - daily driver

Henry Schuman
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Re: Alternator belt - help!

Post by Henry Schuman » Mon 17 Sep, 2018 12:40 am

DAYCO # 15385 will solve your problem available here and maybe somewhere in OZ Ville I dunno
https://www.amazon.com/s/ref=nb_sb_noss ... dayco+belt
Don't Squat With Your Spurs On !!!!

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Christo C
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Re: Alternator belt - help!

Post by Christo C » Mon 17 Sep, 2018 8:33 am

Excuse my ignorance, but I would try the tighter belt and a lot of force to get it on.... even with soap (which you can wash off later).
~Christo
1986 230E W124.023 M102.982 Thistle Green Saloon "Janis"
Beaconsfield, SYDNEY

CraigB
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Re: Alternator belt - help!

Post by CraigB » Mon 17 Sep, 2018 10:34 am

Obviously though it would seem something is not quite right and possibly linked to the snapping of the old belt - never snapped a belt myself in 40 or so years. And obviously with million or two of these M110 motors drifting around over the years, the stated belts will be correct. I'm guessing that belt does water pump, crank, alternator, so the only thing i can think of is that it is not the correct alternator or incorrect adjusting bracket (if they have one) - I don't know the motor and just trying to help with logical thought. Albany is not exactly Perth but the member Giles used to have your motor in earlier car and sometimes has bits. I wonder if you took a photo or he did if that narrows things down. Better still another W126 280 owner. I just have trouble believing that there is not a fan belt readily available to fit an M110 motor and there must be something more behind this. If you can stretch one on you don't want it to break again was the trigger for me speaking up.
Craig Baulderstone
Lurch
280s's
280SE3.5
280SL
350SL
500SEC's
560SEL's

Henry Schuman
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Re: Alternator belt - help!

Post by Henry Schuman » Tue 18 Sep, 2018 3:09 am

Christo C wrote:
Mon 17 Sep, 2018 8:33 am
Excuse my ignorance, but I would try the tighter belt and a lot of force to get it on.... even with soap (which you can wash off later).
No ignorance implied however.......
Forcing a Wrong Fit Belt can do damage to Edge of belt ,over stressing bearing in alt and water pump.
I have run into this dilema on several occasions in the past and My Dayco
(OLD ISSUE ) calls for a 15385 on that Engine as well as a 15380 but it is U.S.A. version
Don't Squat With Your Spurs On !!!!

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Bartman4800
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Re: Alternator belt - help!

Post by Bartman4800 » Tue 25 Sep, 2018 11:41 am

As Craig suggested above, did you check whether all your pulleys are free spinning (apart from the crank pulley)?

If you snap a belt, a bearing might have seized on the alternator or the water pump. (or another auxilliary)

Bart
1963 220 Sb Sedan "Kermit" (Australian Assembly)
1960 220 Sb Sedan "Zum Schlachten" (Early German Assembly, with a torsion bar spring for the bonnet) - Stored in Country WA
1981 Subaru Brumby 1.8 with Weber and 5-speed box "little utie" - Sold to another enthusiast!
2006 Ford Focus "daily driver"
2002 VW Passat V6 30V Station Wagon (SOLD - This car into a money pit)
2011 Kia Sportage "Missus commuter Bus"
2002 Mitsubishi Rosa Bus (converting it to a motor home)

CraigB
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Re: Alternator belt - help!

Post by CraigB » Tue 25 Sep, 2018 12:29 pm

The main problem seems to be getting a belt that will fit. I can't get away from the point that this engine was fitted to Benzes from 1972 to something like 1985, in S, E, SL, G wagon etc etc - I can't imagine how many of these engines there are across the world. I have never seen a post saying 'i can't buy a belt that fits" - logic would say something is not quite right. The original poster sounds like they understand the adjusting mechanism and is getting movement of the alternator to adjust to get it on. The only thing i can think of is that say a past owner has bolted up an alternator from something else - alternators can look very similar on different cars - and say the pulley on that alternator is a bigger size or the casting is a bit different eg. longer/bigger mounting. That past owner could have got a big lever and got a belt on there, damaged as Henry suggested and that is how it broke. My first step would be to find another 280 and look under their bonnet - look at their alternator, read the size off their belt etc.
Craig Baulderstone
Lurch
280s's
280SE3.5
280SL
350SL
500SEC's
560SEL's

sinbad2
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Re: Alternator belt - help!

Post by sinbad2 » Fri 28 Sep, 2018 1:23 pm

I recently replaced the alternator belt on my 85 280SE and it is an 11A0980 made by Gates.
Perhaps there is a problem with the adjuster?

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Astro-Benz777
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Re: Alternator belt - help!

Post by Astro-Benz777 » Sat 29 Sep, 2018 2:37 pm

Bartman4800 wrote:
Fri 31 Aug, 2018 7:10 pm
With the shortest belt, you might have to take out the adjustment bolt, slip the belt on and reinstall the bolt.

If they have a size in between, that might serve your purpose.

If you lived a bit closer to Rockingham, you could pick one up from me for 5 bucks; I got my hands on 100 different sizes...


Bart
Are you willing to post a set for my 280SE to Melbourne? I've been dreading going to one of the parts stores with my Mercedes OE part numbers and trying to translate into "modern" as they snigger at me!
I'm happy to pay more than $5ea too plus postage on top.
W126's: truly the last real Benz (IMHO) :notworthy:
FORMER FAMILY:
1989 300SE (W126) Midnight Blue, Blue/Grey Interior (Gearhardt)
1982 380SE (W126) Thistle Green, Tan Interior (Sherman)
CURRENT DAILY DRIVE & BELOVED FAMILY MEMBER
1984 280SE (W126) Thistle Green, Tan Interior (Hilda...after my late Gran)

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Bartman4800
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Re: Alternator belt - help!

Post by Bartman4800 » Mon 01 Oct, 2018 1:02 pm

Astro-Benz777 wrote:
Sat 29 Sep, 2018 2:37 pm
Bartman4800 wrote:
Fri 31 Aug, 2018 7:10 pm
With the shortest belt, you might have to take out the adjustment bolt, slip the belt on and reinstall the bolt.

If they have a size in between, that might serve your purpose.

If you lived a bit closer to Rockingham, you could pick one up from me for 5 bucks; I got my hands on 100 different sizes...


Bart
Are you willing to post a set for my 280SE to Melbourne? I've been dreading going to one of the parts stores with my Mercedes OE part numbers and trying to translate into "modern" as they snigger at me!
I'm happy to pay more than $5ea too plus postage on top.
Sure I am happy to post 1 or more.

I will have a look at which sizes I have.

So you are looking for sizes between 11A0965 and 11A0980?

Bart
1963 220 Sb Sedan "Kermit" (Australian Assembly)
1960 220 Sb Sedan "Zum Schlachten" (Early German Assembly, with a torsion bar spring for the bonnet) - Stored in Country WA
1981 Subaru Brumby 1.8 with Weber and 5-speed box "little utie" - Sold to another enthusiast!
2006 Ford Focus "daily driver"
2002 VW Passat V6 30V Station Wagon (SOLD - This car into a money pit)
2011 Kia Sportage "Missus commuter Bus"
2002 Mitsubishi Rosa Bus (converting it to a motor home)

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Astro-Benz777
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Re: Alternator belt - help!

Post by Astro-Benz777 » Mon 01 Oct, 2018 1:58 pm

Bart, I'm embarrassed to say I'm not sure.... believe it or not, I have not yet needed to replace any belts on my 280SE but know it's in the near future so thought I'd seize the opportunity while it presented itself. (hope you don't mind)
I had a 300SE the same colour as your 280 (in your avatar, I assume it's your blue beauty) but it had the serpentine belt of the M103 engine... a different beast entirely, both incredible cars to own and drive, the 280 however takes the crown in my eyes but I digress........
As a 280SE/L owner, you'd know the standard belts for my Hilda (see "signature") I'm guessing (hoping), so would you be able to send me a set of standard sized belts for all? (except the smog pump)
If that's all good, just drop me a PM with the total cost including postage along with your bank (or "other") payment details and I'll get that sorted post haste.
I am sincerely grateful for the assistance, I loathe going into the big parts stores.
W126's: truly the last real Benz (IMHO) :notworthy:
FORMER FAMILY:
1989 300SE (W126) Midnight Blue, Blue/Grey Interior (Gearhardt)
1982 380SE (W126) Thistle Green, Tan Interior (Sherman)
CURRENT DAILY DRIVE & BELOVED FAMILY MEMBER
1984 280SE (W126) Thistle Green, Tan Interior (Hilda...after my late Gran)

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Bartman4800
300 SLR
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Re: Alternator belt - help!

Post by Bartman4800 » Mon 01 Oct, 2018 3:21 pm

Astro-Benz777 wrote:
Mon 01 Oct, 2018 1:58 pm
Bart, I'm embarrassed to say I'm not sure.... believe it or not, I have not yet needed to replace any belts on my 280SE but know it's in the near future so thought I'd seize the opportunity while it presented itself. (hope you don't mind)
I had a 300SE the same colour as your 280 (in your avatar, I assume it's your blue beauty) but it had the serpentine belt of the M103 engine... a different beast entirely, both incredible cars to own and drive, the 280 however takes the crown in my eyes but I digress........
As a 280SE/L owner, you'd know the standard belts for my Hilda (see "signature") I'm guessing (hoping), so would you be able to send me a set of standard sized belts for all? (except the smog pump)
If that's all good, just drop me a PM with the total cost including postage along with your bank (or "other") payment details and I'll get that sorted post haste.
I am sincerely grateful for the assistance, I loathe going into the big parts stores.
Sorry, I do not own a 280SE. I am pretty sure others here know exactly which size it should be.
A quick search online shows a 13A925 and a 10A1025 belt. But that might be for a version without AC.

Yes, a 300 SE has a M103 engine, so hence the serpentine belt...

Bart
1963 220 Sb Sedan "Kermit" (Australian Assembly)
1960 220 Sb Sedan "Zum Schlachten" (Early German Assembly, with a torsion bar spring for the bonnet) - Stored in Country WA
1981 Subaru Brumby 1.8 with Weber and 5-speed box "little utie" - Sold to another enthusiast!
2006 Ford Focus "daily driver"
2002 VW Passat V6 30V Station Wagon (SOLD - This car into a money pit)
2011 Kia Sportage "Missus commuter Bus"
2002 Mitsubishi Rosa Bus (converting it to a motor home)

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Astro-Benz777
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Re: Alternator belt - help!

Post by Astro-Benz777 » Mon 01 Oct, 2018 3:44 pm

My apologies, I got confused with your avatar & another!
No stress though, with very little effort and the bonus of gaining knowledge I'll have for a lifetime, I'll get that info & PM you with the details. Many thanks again.
I do know there's four separate belts I need... forgive my ignorance but do you know, or can anyone tell me if the Gen 2 W126 era engines were the first MB engines with a single serpentine belt?
W126's: truly the last real Benz (IMHO) :notworthy:
FORMER FAMILY:
1989 300SE (W126) Midnight Blue, Blue/Grey Interior (Gearhardt)
1982 380SE (W126) Thistle Green, Tan Interior (Sherman)
CURRENT DAILY DRIVE & BELOVED FAMILY MEMBER
1984 280SE (W126) Thistle Green, Tan Interior (Hilda...after my late Gran)

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Bartman4800
300 SLR
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Joined: Fri 10 Oct, 2008 12:10 am
Model you own: w111
Location: Perth WA

Re: Alternator belt - help!

Post by Bartman4800 » Mon 01 Oct, 2018 4:15 pm

Astro-Benz777 wrote:
Mon 01 Oct, 2018 3:44 pm
My apologies, I got confused with your avatar & another!
No stress though, with very little effort and the bonus of gaining knowledge I'll have for a lifetime, I'll get that info & PM you with the details. Many thanks again.
I do know there's four separate belts I need... forgive my ignorance but do you know, or can anyone tell me if the Gen 2 W126 era engines were the first MB engines with a single serpentine belt?
The 6 cylinder in the gen 2 was the 300SE. This is an M103 engine, which uses an automatic belt tensioner with Serpentine belt.
The rest are V8's (M116 and M117) with a different setup.

Bart
1963 220 Sb Sedan "Kermit" (Australian Assembly)
1960 220 Sb Sedan "Zum Schlachten" (Early German Assembly, with a torsion bar spring for the bonnet) - Stored in Country WA
1981 Subaru Brumby 1.8 with Weber and 5-speed box "little utie" - Sold to another enthusiast!
2006 Ford Focus "daily driver"
2002 VW Passat V6 30V Station Wagon (SOLD - This car into a money pit)
2011 Kia Sportage "Missus commuter Bus"
2002 Mitsubishi Rosa Bus (converting it to a motor home)

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Astro-Benz777
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Re: Alternator belt - help!

Post by Astro-Benz777 » Mon 01 Oct, 2018 6:29 pm

Yup, my current daily drive is a 280SE (Gen 1, 1980-85) the car I had immediately previous was a 300SE (Gen 2, 1986-1991) both cars are Inline 6cyl engines... essentially the 300 is the "Post-Update" 280.
The engine from the 280 being the "Old Faithful" of the Benz engine lineup, the "unbreakable" M110.9x. Having been used since 1972 in a whole range of chassis including W114, W123, W116, R107 & C107 as well as in what was the "Entry-level" model of the W126 here in Australia... my favourite, the 280SE/L, it was a tried and tested engine and truly deserved its reputation as "unbreakable".
I'm far less well acquainted with the V8 W126's but I believe the M116.9x in the 380 & 420 SE/L & M117.9x in the 500 & 560 SE/L respectively.
The replacement of the M110.98x with M103.98x (280 and 300 respectively) was the most significant change in fundamental engineering that took place during the 1985/86 "Update".
Interestingly, despite the quite visually radical change that took place with the W126 range, there were no metal fold changes across the whole 11 year run.
image-MKCAHR8X.jpg
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W126's: truly the last real Benz (IMHO) :notworthy:
FORMER FAMILY:
1989 300SE (W126) Midnight Blue, Blue/Grey Interior (Gearhardt)
1982 380SE (W126) Thistle Green, Tan Interior (Sherman)
CURRENT DAILY DRIVE & BELOVED FAMILY MEMBER
1984 280SE (W126) Thistle Green, Tan Interior (Hilda...after my late Gran)

CraigB
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Re: Alternator belt - help!

Post by CraigB » Mon 01 Oct, 2018 7:15 pm

How do you compare the 300 to the 280 in every day use? I had the impression that the 300 was more fuel efficient and a step forward, but something nice about a twin cam motor.
Craig Baulderstone
Lurch
280s's
280SE3.5
280SL
350SL
500SEC's
560SEL's

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Astro-Benz777
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Location: Melbourne

Re: Alternator belt - help!

Post by Astro-Benz777 » Wed 03 Oct, 2018 7:34 pm

CraigB wrote:
Mon 01 Oct, 2018 7:15 pm
How do you compare the 300 to the 280 in every day use? I had the impression that the 300 was more fuel efficient and a step forward, but something nice about a twin cam motor.
I might well be the exception that proves the rule Craig but IMHO;
Although the 300 represented a giant leap forward in engine technology & the M103 is a much more modern engine type. As far as fuel efficiency goes, a well tuned and maintained 280 will be as efficient or moreso than a poorly maintained or high Km's 300 but if both were equally cared for, certainly the 300 would get more km's per liter BUT...
If one is an enthusiast &/or enjoys the maintenance/tinkering as much as the driving, the 280 takes the cake. It's a much more "Logical" engine, relatively easy to get to know/understand so far more conducive to being maintained by a DIY'er.
....and YES! I couldn't agree more that the M110 is a deeply satisfying engine from an engineering or design standpoint. The DOHC setup makes it a beautifully balanced looking/feeling engine, while the peripheral systems are a true marvel of German Automotive Technology.
In answer to your question, I would take the whisper quiet & smooth as silk (when correctly tuned) 280 every time (though would take a 420 over a 380.... probably). I think the 280 is the perfect match for the SE chassis... just enough grunt so you still feel the size and weight of the vehicle but I think it'd be a little too underpowered for the extra 4" of the SEL.

My 10 cents!
W126's: truly the last real Benz (IMHO) :notworthy:
FORMER FAMILY:
1989 300SE (W126) Midnight Blue, Blue/Grey Interior (Gearhardt)
1982 380SE (W126) Thistle Green, Tan Interior (Sherman)
CURRENT DAILY DRIVE & BELOVED FAMILY MEMBER
1984 280SE (W126) Thistle Green, Tan Interior (Hilda...after my late Gran)

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