1998 V70 Alternator Bearing Rebuild Thread

[volvolugnut]

My 2 cents:
For the minimal cost difference go with the bearings that have the tolerance rating, even if the others do not tell you their rating. More specs is a general indication of better specs. Also, SKF has a very good reputation for quality.
Two seals are better than one, but this is not a high contamination area to my thinking.
Also, when I last replaced brushes on an alternator, I used an impact phillips driver to remove screws. One of those ugly hammer impact tools actually work very well.
volvolugnut

[yanga001]

Cost wise, i am in it for my hours right now. I am going to find a dremel and cut off the old bearings and will swap them with the better new ones. The rear old bearing went out, front one seems useable but i dont want to go back in again.

The screws seem to be a bit of a lost cause at the moment and ill drill them out and use 2 bolts and locknuts fixated to hold them in place. It was much much easier to bang out the shaft than it was to try and unscrew seized fasteners. As far as i gather, the bearing is press fit in and makes minimal contact with the screwed in plate. Ill cut the plate at 2 screws and drill out the other to give a channel for the nut and bolt.

[yanga001]

Did some maths for Canada based shipping.

bearings from BDIdirect for the fancy cold rated -30 - 150 celsius 6203 and 6303's come out to 50, and then 66.36 with tax.

I will decide if it warrants a new slipring today but im budgetting 30$ cad with tax for it

A bearing separator from amazon comes to 69 pre tax and 78 post tax.

Total comes out to roughly 174 total.

Looking around a bosch alternator through volvo is 491 cad :O
A junker one from a yard comes to 35$ cad however i have not seen a 98 or 850 for a long time.
a remanufacture by bosch is 282 by parts avatar.

Pros: i know i have an alternator rated for cold weather operations (-30 lol, girly might want to move to alberta one day) and will at least last the life of the car. Cons: spent 174 when i could grab a used one for probs 80-100 from some local friends, saw some advertised for 120. Learned a lot however so that will way into the decision. Will do the purchase today after checking out the slip ring.

Edit:
i could knock out the bearing separator by dremeling and then splitting off the old bearing and installing the new ones. Would bring the total cost to about 100$ + a gajillion hours of untrained labour.

[abscate]

Plan C

Find a local British car club and ask them who rebuild their. electrical stuff. Take your OE Bosch to that guy/gal and have them do it for about $100. You keep your goodBoschstuff and don’t get a rebuilt made from a crushed Prius

[volvolugnut]

The bearing separator would be a tool purchase and usable for a lifetime of other projects. I would not include it's cost in this project.
volvolugnut

[yanga001]

The bearing separator would be a tool purchase and usable for a lifetime of other projects. I would not include it's cost in this project.
volvolugnut

I am starting to think that way.

Took a detailed look at the slip ring and rear bearing and it looks like the rear one seized up and lost its centre. It wore out the inner slip ring by about 1.5 mm more then the outer copper. Thinking of replacing the slip ring as well. Took a wire brush to the outer frames and they look a lot better. Packaged it all up with cloths to protect the coils and put it away.

All coils tested clear for contact to one another. The wires are bundled in 3 sets and the first two, next two, and last two are connected together. They should not test as connecting to wires outside their pairs, a simple continuity test suffices.

The slip rings were tested at approximately 2.8-3 ohms which seems to be correct from what ive looked up.

Also, BMW forums show C3 clearances are the standard for automotive bearings.

Will do the order for bearings and slip rings tomorrow. I might grab the bearing puller as well, and find my dremel to cut notches into the front mounted screws.

[yanga001]

Update:
Completed the disassembly, the dremel was the answer. Cut off the old bearings with ease and cut slots in the top screws to get it out. Little bit of surface damage to the alternator but nothing structual.

Turns out this alternator was rebuilt once before.

The front bearing was an NTN, back bearing was a Nachi. Slip ring probably could use a change at this point.

If i change all the parts, the b*stard never needs to be taken apart again is the hope.

Resistance tests passed on all coils and what not.

Assembly at this point is interesting. Looks like the rear bearing is shaft first then just press together.

Front bearing looks like you could body mount it first into the front frame, screw it together, then tap it onto the shaft by hitting the centre of the bearing.

Will probably post a full teardown with photos and the tricks i had later this week.

The rear bearing was destroyed, the interior grease was gone, and half of the runners for the balls seemed to have disintegrated.

[abscate]

#respect

I love people who never give up.

4 ever!

[yanga001]

Purchased the slipring and bearings. Came out to about 100 due to purchasing some fancy bearings. slip rings up here get hit with shipping and tax from the states. If it works, then 100$ full rebuild >>> purchasing a junk one.

[yanga001]

Made some time over the last 2 days to work on the alternator. New bearings came in and documented and reassembled it. Of note, the slip rings for 1999+ vehicles are swapped in polarity but not in form when compared to the 1996-1999 alternators. I ground off the placement ring and set the ring in the correct orientation. This was determined through resistance testing to see which lines were shorted from connector to coil and which went through the coil.

When reassembled i had a few mm of play in the alternator. I inefficiently spent close to 1.5 hours using a dremmel to file a washer into a spacer that sat on the bearings inner race and would allow the alternator to be placed and spin freely. I am happy to say it seems to have all gone back together correctly and a full proper writeup is in the works.