I realize you've already determined to replace your bearings, I thought I'd share my experience though for the benefit of others.

The PO replaced the alternator with an autozoo reman about a month before I bought it (2014ish I believe)

I had a funny *ting* sound now and then from under the hood of my grey car. like someone hitting a tuning fork or a high note on a guitar string or something.

It'd run fine, quiet, no growls or funny sounds and then *ting. *ting*, then a pause for a few seconds *ting* and then wouldn't do it for a few minutes sometimes.

I chased the problem around, swapped in a different fan clutch thinking it was that. belts were all good, not the A/C compressor, it was the alternator.

When I pulled the alternator I discovered very slight play in the bearing/shaft, but very minimal, barely detectable.

I did the AL129X upgrade with some help from my local parts place that said they'd take my 55amp unit in as a core for the upgrade alternator. cost me like 100 ish bucks for a brand new bigger alternator with a lifetime warranty (I know, its probably cheap chinese parts, but when you get free replacements for decades...)

Installed the new one, no more *ting*-ing sound.

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1982 300D (w123, "Grey Car")
1982 300D (w123, "Blue Car")
2001 Ford F150 "Clifford" (The Big Red Truck)
1997 Dodge Ram 2500 12V Cummins
1996 Dodge Ram 2500 12V Cummins
Previous Vehicles:
1995 E300D, 1980 300SD, 1992 Buick Century, 2005 Saturn Ion

If you order from Rock you won't know where the bearing is made till you get it.

Also National, Timken, SKF and other brand name bearing makers have several grades of bearings and they all sell Chinese Bearings in the lower grades.

I have had good luck on ebay asking the seller where the bearings are made of if the bearings that they are selling match the picture and I can see where the bearings are made on the box or bearing.

I have also seen bearings made in Argentina and Korea.

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84 300D, 82 Volvo 244Gl Diesel

Is there a lubricant I could spray or place into the bearing on the alternator that would help make it last a little longer until I get the parts?

It's a sealed bearing, so there would be no way to do this while its in the car. Remove and disassemble the alternator, very carefully pop the seals off the bearing, clean and grease the balls, then reinstall the seals, reassemble the alternator, and reinstall it into the car. Seems like more trouble than its worth. Plus the bearing side seals get hard with heat/age, so your chances of popping them off intact is pretty slim.

The rear bearing in your '84 alternator - which is the easy to replace one, and the one that usually goes bad first - is a 6202-2RSJ type (very common size). A good SKF brand one is ~$18 retail. You'll also want a new plastic tolerance ring (~$2) and a new voltage regulator (MB p/n 002-154-58-06 or Bosch p/n 1197311090 ~$30) because it would be silly not to replace those things while you're in there.

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1998 E300 turbodiesel

America's Rights and Freedoms Are Not The Enemy!

Do you not have any place in your town that caters to industrial stuff? Those shops have an entire section of bearings and have all of the stuff you want.

6202 2RS is a pretty standard issue bearing (even skateboards use it). Go to a good NAPA store and ask them for an SKF item. If you see the box says france or any EU country you are good.

Orielly sell National which are great too. if you are overthinking it then get an american one, pop a seal off carefully, wash it clean and use the best bearing grease in there.

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2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

Sure it's not a 6201?

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When cryptography is outlawed, bayl bhgynjf jvyy unir cevinpl.

I use a small hose instead of my stethoscope. A bad bearing will also generate heat and leave the surrounding housing hot. Wet your finger before you touch the bearing area.

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84 300SD
85 380SE
83 528e
95 318ic

The data I have says 6202 for all 1984 Mercedes models.

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1998 E300 turbodiesel

America's Rights and Freedoms Are Not The Enemy!

So, pulled the old alternator. spun the bearings....silence. I couldn't detect any plan in the shaft but then I am no expert. I'm going to install the new Bosch AL117X 65 amp alternator either tonight or in the morning.

Then I'm going to attempt to rebuild the old one and let it set on the shelf for a rainy day.

Rainy NIGHT. Alternators never fail on a nice sunny day.