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Sun Feb 07, 2010 8:32 am

Hello,

I don't have a socket big enough to remove the fan nut on my alternator, I am wondering if both bearings are the same? Also, is it possible that the generator and alternator bearings are the same? I haven't been able to find alternator bearings on any of the VW parts suppliers, only generator bearings.

Generator pulley bearing: 17 mm ID x 40 mm OD x 12 mm Wide

Sun Feb 07, 2010 8:36 am

36mm socket for the fan nut. Try Sears or mcmaster.com

Same size as flywheel gland nut and rear axle nuts.

Sun Feb 07, 2010 8:55 am

http://www.thesamba.com/vw/forum/viewtopic.php?t=391152&highlight=

Sun Feb 07, 2010 9:48 am

Yeah new Alt or Gen < Dont mess with the Bushing's !
Cheap source for rebuilt Gen's is think I paid 86 Buck's at a Kragen for a Gen ?
Now the Story's < Gotta tell ya what's Up ?
Most common break down with V.W. 's when you Drive one State to State or Cruise Route 66 From So Cal To Laughlin Or Vegas etc.
Is these Bushing's !
A Bugg will runn for year's around Town No Problem 3-5 Even 6 Year's ?
But jump out on the Freeway and Runn a 70 MPH for 3-5 Hour's straight ? Approx Sustained 28-3500 RPM
THis is when the Bad Alt / Gen Pulley or warped / Bent Fann will manifest itself in the form of a wiped out Alt/ Gen Bushing !
You can Smell um if Heater Boxe's are hooked up . Has the Famaliar Smell of Bronze < Copper and Tinn .
Often Aluminum Crank Pulley's will become grooved by the Belt . Either by Higher Horse Motor's or just plain worn out !
Or bent OEM pulley's < From being Pryed off with screw Driver's etc.
All these as well as Mutilated Pryed on Fann's Badd fitting Fann Shroud's etc
Are all attributed to Blown Gen / Alt Bushing's ! < Real Bummer cause it alway's Happenns 300 miles or further from the House !
Understand that they sell welded Fann's and Balanced Fann's in effort's to minimize this type of Break Down !
I use a Pre sett Impact wrench to Remove and Install Fann << Art Form very Delicate etc.
Even Adjusting the Belt I often see Guy's crank down on the Alt/ Gen Nut with a wrench << Act's as a fulcrum on the Gen / Alt Shaft smashin the Bushing bendin or warpin the Shaft etc.
Another Trick that Ive takin to doing is I will use a thin coat of aviation on the Moon Keys and Shafts both on Pulley and Fann .
New Fann Dog is also very Nice thing to have ?
Just be carefull not to bend fold spindle or Mutilate Fanns or the Alt / Gen shaft etc.
Use a Lott of Care !
Understand the Problem then take Stepp's neccessary not to make the Mistake's over again .
Also there are Different width fann's availiable !
Last But not least Start car lett her warm up observe the Crank Pulley and belt for smoothness and is it runnin straight ?
On long Trip's alway's carry a spare Gen / Alt and Tool's to do it with !
Hollbrook Az 2 Day's waitin on a Gen ?
Nice Motel's Nice People I think except for the ones that were Drunk < wich was all of them I think ? Go Figure !
Sean

Sun Feb 07, 2010 10:30 am

Candymustang, these are the bearings I am thinking about. Their dynamic load ratings are stronger than the stock replacement.

They are almost double the price of the stock ones, but I think it's a worthwhile investment. I have replaced bearings on a generator so I have that little bit of experience.

www.appliedindustrial.com

Fan side: 15x35x11
SKU:2514222
Dynamic load:1930LBF
Static load:830LBF

Pulley side: 17x40x12
SKU:2514651
Dynamic load:2450LBF
Static load:1060LBF

Stock recommended bearing (15x35x11)
SKU:5143995 (FAG 6202, unsealed version)
Dynamic load:1730LBF
Static load:850LBF

Mon Jun 20, 2011 12:52 pm

I just order a set from them, and got a call back indicating that those SKU's point to bearings that are a bit more rare because they're only sealed on one side. The bearings with the exact same specs, but sealed on both sides are much more common, a bit cheaper, and available from most of their facilities (as opposed to just a small inventory at one).

SKF Brand
Mfr Part number 6203 2RSJEM
and
Mfr part number 6202 2RSJEM

Sun Jun 26, 2011 8:28 am

Since this it the best thread I found for "Alternator Bearings", I'll repost this here.

I received the stronger bearings earlier this week, and tore into it today.

Getting to the bearings wasn't that challenging - I had read that others didn't want to tackle it without a proper shop, but it was fine working on the ground. Tools needed are a hub puller, a screwdriver and a deep dish socket and small hammer for seating the new bearing.

Pull the alternator from the car. Use the hub puller to remove the fan hub, remove the pulley and backing plate (if you haven't already). Remove the three screws from the face (pulley side) and lift off the cover. Careful not to lose the thin wavy washer that sits between the cover and the bearing. Now use the hub puller to pull off the bearing and spacer.

Now flip it over and remove the two long screws from the back (fan side). Use the hub puller to remove the rear cover and spacer.

The strait spacer goes on the outside and the stepped spacer rides on the inside.

On the backside of the rear cover, there are two small screws holding down the bearing cover.

The bearing should slip right out.

At this point, you can also remove the shaft from the front (fan side) and inspect it and the brushes. If you have to replace them or the regulator, now's the time to do it.

On reassembly, I had to play with a flat head screwdriver to get those bushings back into place to slide in the shaft.

Now, reassemble. Start with the front bearing - set it on the shaft and stand the shaft against the work surface. Use a deep dish socket to strike the inner race (DO NOT STRIKE THE OUTER RACE) using a small hammer to drive it into place - down to the shoulder on the shaft. Also drive the outer bushing over the bearing. Reinstall the shaft back into the alt housing. Don't put on the front cover yet.

Continue with the rear bearing - set it in the rear cover, bolt the cover back over it, set the stepped spacer so it sits on the inside of the bearing and start it on the shaft. Set the shaft against your work surface and DO NOT STRIKE THE COVER - you'll want to set the outside spacer on the shaft and strike against that spacer. I used a deep-dish socket and small hammer to tap it into place. Drive it down to the shoulder on the shaft. Use a bit of locktite on the screws, and screw the back cover into place.

Flip it over and screw the front cover back into place - locktite on the screws. The cover on my alt didn't center itself completely and I had to tighten it down twice - the first time it didn't rotate cleanly and I had to loosen the screws, re-center the cover and retighten.

I had held on to my older alternator, thinking I'd rebuild it prior to swapping it out and practiced taking it apart. It was ripped up! The rear bearing had seized and the alt shaft had been spinning along the inner race - totally shot:

Moral of the story: don't ignore bad bearings! They're not that difficult to change.

Sun Jun 26, 2011 10:00 am

nice job with the photos and descriptions! yeah these bearings are very easy to swap out. i'm always puzzled by folks who buy an whole new alternator when just the bearings have failed. of course the bearings generally last a very long time.... unless you over-tighten the belt (as many folks do).

also, a good 36 mm socket that is very low profile is the mercedes benz oil filter housing socket. it's 36 mm, six point, 3/8" drive, but very shallow and low profile and good for vw fan and crank nuts.

Sun Jun 26, 2011 10:05 am

torsionbar wrote: nice job with the photos and descriptions! yeah these bearings are very easy to swap out. i'm always puzzled by folks who buy an whole new alternator when just the bearings have failed. of course the bearings generally last a very long time.... unless you over-tighten the belt as many folks do. I fell into that category - my last two alt purchases were due to bad bearings (different thread). I couldn't find any good thread on how to swap them - even found some advice on not doing it without a pro shop - totally disagree.

Thu Jul 07, 2011 5:13 am

Quote: also, a good 36 mm socket that is very low profile is the mercedes benz oil filter housing socket. it's 36 mm, six point, 3/8" drive, but very shallow and low profile and good for vw fan

Another one that works for removing the fan with the engine installed is called a Crowfoot Flare Socket but in a 1 7/16 size. What can I say, it was given to me.

http://www.sears.com/shc/s/p_10153_12605_SPM316939...33348210-2

Thu Jul 07, 2011 7:41 am

Nice I like it >
Can honestly say Ive never changed bearing's out in an alt .
Alway's bought a new one .
But now you can concentrate on what made the bearing go badd in the first place .
List of Suspect's is ?
1 ) Warped or imbalanced fann .
2) Badd belt pulley
3) Badd crank pulley
4) Badd fitting fann shroud that causes misaligned crank and alt pulley's .
Note : Bugg's will runn around Town for year's and year's 20 mile trip here and 30 mile's there etc.
But the most common of break down's on long road trip's exceeeding 100 + mile's of freeway driving .
Is the Alt / Gen bushing and bearing's !
The reason is sustained cruise-ing R.P.M.'s for 2or 3 sometime's 5 or 6 hour's with an imbalanced fann or any of the other condition's I mentioned above .
Meaning if you adjust your belt and it is still lope-ing you either have a miss in the engine cause-ing the lope or one of the pre amention'ed condition's exist and it will almost undoubtebly blow a Alt or Gen / bearing / bushing on a long trip .
Cause and affect . :twisted:
Sean

Sat Jul 09, 2011 1:48 pm

excellent write up!

I have a no-name chinese alternator, that has UNDER 100 miles on it, that started grumbling. I took the belt off and ran the motor to be sure it wasn't coming from the engine. I also tightened the alternator stand strap.

I'm guessing there are just cheap chinese made bearings in it, and some SKF's should last awhile? I bet the Bosch branded alternators have crappy bearings too?

Sun Jan 15, 2012 3:42 pm

I am having bearing problems line mentioned above, but instead of the bearing being bad, the back cover (fan side) where the bearing sits is wallered out a little bit, causing a loose fit, and a wobbly fan. Any ideas on what to do here? Try and get a core to fix it or what?

Sun Jan 15, 2012 5:41 pm

Ack, can't edit anymore:

Ian Epperson wrote: At this point, you can also remove the shaft from the front (pulley side) and inspect it and the brushes. If you have to replace them or the regulator, now's the time to do it.

Kangaboy, if the housing is "wallered out" I'd say it's done. Either find a doner alt where you can get the cover or replace the entire alternator. It probably got wallered out because of a bad bearing spinning in place - similar to my bad bearings eating up the shaft in the pic above. Was it making noise?

Sun Jan 15, 2012 6:20 pm

no, no noise at all...the only reason i ever noticed it was wobbly is because i had to take off my crank pulley, and in doing so i was taking off and putting on the alt pulley to get the belt on, and off. While i was putting the belt back on i noticed that the alt was a little wobbly.
Its funny what candy mustang said cause its true. I had 50,000 miles on that alt, and it was fine. It was only when i drove straight through from St. Louis Mo, to Los Angels that it got fried (32hrs, 1800miles).

Sun Feb 05, 2012 3:24 pm

MY Stock 12v gen has two, 6202z bearings. NSK maker (2 metal shields)
i found some nice Timken 202SS

202 is no seals
202-FF is 2 rubber seals.
202S is one side metal shield.
202SS two side metal shields and crosses in the Timken cat

these are pre greased bearings, and will last until the grease goes bad
which will not be forever,, no sealed bearing lasts for ever.
50k ? design life. there are charts in the timken eng. section showing this.
heat/load/temp.
the timkens are not cheap but or real high quality and usa made.

http://www.summitracing.com/parts/TMK-202FF/

http://www.summitracing.com/parts/TMK-202SS/

http://www.rockauto.com/catalog/catalog.php?catalo...EN%2B202FF

rock has both for $9.00

Sun Feb 05, 2012 4:42 pm

super Alternator page, so i add the book end , MR. GEN.
my 68 gen (actual)
http://ac-vw-remove.com/How_to_fix_it/electrics/generator/gen.html

do not buy or use China no name bearings.
Use Timken, NSK, FAG, or National or NSK
not SOM TING WONG :oops:

i see odd parts here too, shims, cool.
http://vwparts.aircooled.net/VW-Alternator-Volkswagen-Generator-s/339.htm

Mon Feb 06, 2012 1:39 am

Hi Guys,
Thanks for a great thread - I think my bearings are shot too & thinking about getting them changed. (grumbling when engine is hot after a few miles TBH, I've got checked it out properly.
Alternator is off a 70's Jeans bug which I got many years ago so its been idle for many years (15ish!). I was going to give it too a auto electrician to do, but I think I'll give it a go myself after reading this thread! :D :D

Mon Feb 06, 2012 5:59 am

yes, any good auto electric shop can do this.
just be careful not to damage the brush holders, going back in.
find a way to retract the brushes, many models of gen/alt
have magic hole that allows a paper clip or a tooth pick to lock them back.
some alts, the elect. reg,is in the front section and needs unsoldering first.
not this one, it's the friendly type.
use a puller and avoid the pry bar.
cheers !

Mon Feb 06, 2012 9:36 am

schadenfreude wrote: many models of gen/alt
have magic hole that allows a paper clip or a tooth pick to lock them back
Ooh, good tip! While I was sitting there working the brushes to get the shaft back in, I was thinking that the pro places must have some trick to making that step easy. I didn't think to look for a set of "magic holes".