m73m95

The bearings I got disintegrated after about 20k miles... But I didn't get them from the link in this thread either. I tried to be sneaky and source my own.

I threw the voltage regulator into a used alternator, and it works perfectly to this day. 1980's Germany makes good bearings

danspach

I'm pretty sure I over tightened my belt when I replaced my AC compressor (that was way back when you hosted the Dyno day Van). Will the gauge on my dash read erratically if the bearings are bad or is that more likely the voltage regulator? Is there a discernible bearing noise or can you only tell by taking off the belt and grabbing the pulley?

When I say erratically, it doesn't bounce around like it's a loose wire on the gauge but one time it will read 13 volts and then the next time I drive the car it will read just above 12....my battery has been dead a few times (a new one) before I really paid attention to the gauge.

Being mindful of and conservative with my draw ( no fog lamps, etc) has preserved it for a few months straight but I gotta fix ger over the winter so trying to plan.

Austin09

Hi guys,

the links don't work for me. What bearings do I need to order to rebuild the alternator?
Please could you let me know the spec and type of bearing to buy as I'm from the UK so will be buying from a uk website.

Austin09

About an hour searching around I found this - has all the component parts for the alternator should anyone need it in the future.
http://www.woodauto.com/Unit.aspx?Ma...Ref=0120468004

Now comes the more daunting part - I have a turbo, everyones saying its a nightmare to remove, but everyone is approaching from the top of the engine. Is it possible to remove from underneath? I'm renting a ramp for the day soon so access will be great. I inspected the belt this weekend and it doesn't look like anything is obstructing it dropping out, but I can't see how to get on the bolts.
Please let me know if you know an easier way than clarks garage suggests.

Van

The AC compressor would need to come out first, if you're pulling it out the bottom...

I'd say the top side is easier...

Austin09

Cheers. I can do that job on the driveway then.
As for the rebuild, I want to just change the bearings. Can I get away with just a puller and vice as tools? I'll do the job myself probably and replace any other worn parts of necessary.

Jfrahm

Old thread, but I rebuilt the alternator in one of my 928S4s recently and I (same basic alternator) and I got the bearings I think from JSB Bearings via Ebay. There was a "premium" option I went for, and when the bearings arrived I popped one of the side covers and saw very small grease blobs in there, but it looked like a pretty quality blue synthetic grease. I added more, trying to stop short of packing them to the point where they grease heats up to the point of popping off a seal or being forced out the interface. I use Mobil synthetic bearing grease. IMO the grease escapes over the years and then the bearings run dry and go bad. More grease = more life, until you get to the point where there is way too much.

For voltage regulators I use Huco units off ebay or Amazon:
"Mercedes W102 W103 190E 190D Voltage Regulator Huco 002 154 72 06"

Cheap, working great so far in my 968. I think I blew the last regulator in the 968 due to a missing cooling bonnet, I need to sort that out. It was a no-name unit from a rebuilder or somewhere.
I have not really tested the 928 alternator yet other than on the bench, spun up with an impact gun and lit with a shop battery, but I have rebuilt the alternator in my A8 and it is fine after 15K miles or so.

Bearings from my receipt:
6303-2RS Premium 6303 2rs seal bearing 6303 ball bearings 6303 RS ABEC3
6201-2RS HCH Premium seal 6201 2rs bearing 6201 ball bearings 6201 RS ABEC3

About $4.50 and $2.50
-Joel.

Austin09

Thank you guys super helpful.

My alternator is fine apart from a screech on startup. I plan on just changing the bearings.
This is my first alternator rebuild - just checking, I don't need to replace the regulator do I?
I've found some NSK bearings for a reasonable price - everything in the UK is more expensive though

Tiger03447

When you open the case, don't be surprised if the brushes on the slip rings pop out of their holders. When going back together, some guys use a paper clip to hold them in place when re-assembling the rear section of the case. It may be that on this one, the brush holder will keep them in place long enough to keep it all lined up. Put a mark, paint or whatever, on the side of the cases so they will line up in the correct position on re-assembly. That way all the electrical connectors line up OK when you re-install it in the car, with the wiring harness.

Jfrahm

I would say on the later alternator anyway if you do not pull the regulator and brushes before taking the case apart they are liable to break when the wear area of the slip rings is pulled past them.

Also if your regulator is a quality part it is cheap and easy to replace the brushes rather than the regulator assembly. There are yout00bs on the process and parts are easy to get. There is a guy in Ireland who sells a lot of them and other parts on ebay. A good working regulator with new brushes IMO is better than some new random possibly counterfeit regulator assembly. Brushes can also be had from your local parts store from Standard or whatever.

Austin09

So it sounds like the recommendation is to replace the brushes and regulator at the same time?
I was just going to do the bearings since its running fine just started to make a noise the other week.
I'll have a look for parts now, i've already ordered the bearings from NSK.

Tiger03447

Beautiful work Cass, you too Kevin!

Jfrahm

The brushes are part of the regulator assembly but can be replaced by drilling them out and soldering in new ones. Personally I recommend just the brushes if they need to be replaced, unless your regulator is some no-name one. If it's a good quality part it's $3 or so to change the brushes. Or maybe they are not that worn.

It's easier than it looks and sounds to replace the brushes:

Slip rings are a pain and last a long time so I have not discussed those.
-Joel.

Austin09

Thanks guys. Looking forward to getting my hands dirty.
First, just the nightmare of removing the alternator.

Dchiles08

Hey I'm in the middle of my rebuild and I found that my alternator only has a two peice case unlike the pictures. There's no back cover to pull out the electrical part. Should I be concerned? Also kind of a random question but could a weak/faulty alternator cause my gauges not to work? Thanks for the info already!!!!!