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1998 S70 Alternator Bearing Change DIY

I had a problem with noisy alternator bearings. The symptom was a high pitched noise which was proportional to the engine rpm, but higher. For me it seemed like some plastic is rubbing on another surface. It occurred only when the engine was cold and the car was sitting for some days. Later it occurred at every cold start.

Atis » In this post … 79#p352979 I had a problem with noisy alternator bearings. The symptom was a high pitched noise which was proportional to the engine rpm, but higher. For me it seemed like some plastic is rubbing on another surface. It occurred only when the engine was cold and the car was sitting for some days. Later it occurred at every cold start.

To verify the alternator bearing problem you just have to remove the serpentine belt and rotate the pulley by hand. In my case the noise was not too dramatic but obvious, and in some positions, there was a clearly noticeable radial shaft play.

So to change the bearings you will need a „6203 2RS” , a „6303 2RS” bearing and a plastic „shell” for the rear bearing. I recommend to buy a new slip ring and new brushes (or complete voltage regulator), as if they are worn, you can save the effort of the repeated alternator removal. Four pcs of M4x20 tapered philips head screws are recommended as well, as there is chance that you had to drill them out.
With regards tools you will need:

  • -Philips head screwdriver small and a bit bigger
  • -Flathead screwdriver at least 2 pcs as small pry bars
  • -bearing removal tool, small one (try to get the 2 claws type)
  • -plunger (I hope it is called like that; the small bar you use to knock out small shafts, rivets or screws)
  • -hammer
  • -a bigger hammer  (the rubber type)
  • -vice (the big fat mama type)
  • -solder (the bigger the better, 100W was sufficient for me)
  • -sockets: size 8 and 24
  • -Impact gun
  • -16 socket for spark plugs (or similar size and long enough tube)
  • -angle grinder
  • -fine sand paper (I have used grade1000)
  • -small needle type file

First of all remove the alternator from the car. I would not like to cover this step in details as there are plenty of good description on how to do that. (I recommend the video of Robert Spinner a.k.a. Rspi)

So here is the removed alternator:


Remove the pulley from the front side with a 24 socket. I used an air impact driver. Even a small 3/8 one did the trick easily. You can try to counterhold on the fans inside, but I do not recommend it as they are really soft and you can easily bend them. Without an impact gun, I will just try a breaker bar and hit it with a big hammer.
The pulley should came off easily from the shaft. Below the pulley there is a spacer on the shaft fitted with tight tolerance, so do not try to pry it off now. You will see four philips head screws, those are holding the bearing plate at the inside of the front housing. Pull those screws out. In my case they were pretty badly rusted in, so I had to drill them out. They are M4x20 screws, so a 4.5 drill will do the job.

Front bearing advice.jpg

On the back side there are 3 small philips head screws, remove them and push the plastic clips inside to remove the plastic cover at the back.


Now you can see the voltage regulator, the slip rings and the diodes. Pull the two philips head screws of the voltage regulator and remove it. Clean the contacts.


You can see the 6 electrical connections with the stationary coils. These are double copper wires crimped together. Pry the crimps out and free the ends of the copper wires. (I am not 100% sure that this step is really needed, but if you would like to avoid demaging the coils, you have to separate the houings and the coils)


If all of the wires are free, you can pull the 3 philips screws of the doide assembly and remove it.

Remove the 4 screws which are holding the aluminum housings together (socket size 8). Pry apart the two aluminum housing parts. There is a pretty big gap between the two parts where you can pry. I did that with a big flathed screwdriver, going around the contour of the gap.
The shaft with the bearings will remain in the front housing. In my case the stationary coils just fall out from the aluminum housing, so be careful not to drop it. Make some marks how the pieces are going together.

To remove the shaft from the front housing, I have inserted a plunger in the pulley end of the shaft (it is hollow) and knocked the plunger with the parts above on a vice (shaft vertically, the plunger is below and I just hit the whole thing onto the vice – I was a bit desperate at this point, so I simply forgot to take pic… see second pic for advice). If you repeat that several times, the front bearing will come out slowly from the housing.

Now you should have the two housings and the shaft assembly apart.
Shaft assembly with front housingTo remove the rear bearing use a bearing removal tool. Be aware that the rear end of the shaft is the slip ring itself, which is plastic. It is hollow and some millimeter deeper there is the actual steel shaft. So to avoid damaging the original slip ring with the bearing removal tool, I have put an M3 nut in the hollow end of the slip ring. It was just enough to have a good point for the removal tool’s shaft .

Rear bearing advice.jpg

To remove the front bearing you have to pry off the washer below the pulley first. You can do that with two large flathead screwdriver. Some penetrating oil could be useful here. Note the orientation of the washer (the stepped side towards the bearing).

Now comes the funny part. Grip the front bearing gently in the vice. Place a rag or some kind of towel over the shaft and now let all of your anger, frustration and hate into that bearing by simply crashing it with the vice. Clean off the remaining of the outer ring and the balls. (Obviously be careful not to damage the shaft assembly with this step, so be carefully to grip only the bearing).
To remove the internal ring of the bearing you have grind down that ring until the shaft. I have used a 1mm cutting disc to cut really close to the shaft, and after that grind it further until the shaft was just visible. When you have reached the shaft, you can try to rotate the ring (i. e. punch it with a plunger and hammer). If the material is thick enough near the cut, it will break and then you can pry it off with 2 flathead screwdrivers just enough to place a bearing removal tool below.


(already pried up a bit)


(I used the same tool for the rear bearing)

As the shaft was rusted below the ring, I have used a fine sandpaper to polish it.
Before putting everything back, it is a good time to clean all the parts. I just simply brushed the housings and used some break cleaner for the other parts.

Putting together:

Place the plastic bearing „shell” in the rear housing.


(plastic thingy halfway in)

Place the front bearing in the front housing. You can use a rubber hammer and a large socket (just a bit smaller diameter that the outer ring), but I was able to push that in by hand, pushing with two thumbs repeatedly and going around. Put the bearing plate in place and fix it with the four M4 screws. Be careful with the orientation of the plate, it should touch only the outer ring of the bearing.


Front bearing, cover plate and stationary coils in place.

Place the rear bearing on the slip ring and knock it on place. You can use a long 16 socket for that. I have used the washer from the front side, the old bearing and a socket… jut be careful to hit only the inner ring. You do not have to knock it fully down, just be sure that the connecting surface of the shaft is visible above the bearing.

New rear install.jpg

Clean the wire ends of the coils with sand paper. If they are nice and shiny again, than you can place the coils into the front housing (mind your marks). You could now put the shaft into the front housing. You should be able to push the shaft assembly in the bearing.
If everything is in place you can put the rear housing back in place. I was able to push it down almost totally, but at the end I just put back the 4 screws of the housing and in a cross pattern slowly tightened the screws thus pushing the housings together. Tighten those screws.


Get a small file and clean the crimps of the diode assembly.
Now you can put back the diode assembly. Be careful to lead every wire back to its place. Put the three philips screws back and tighten them.


Fold back the crimps onto the wires. Use a powerful solder to solder the wires back to the crimps. Check that there is a good amount of solder there as there will be some amps in those solder joints.

Put the voltage regulator back in place and tighten it down.
Put back the plastic cover, engage the clips and secure it with the three small philips screws

Clean the inside of the front washer with sandpaper and knock it back on the front side of the shaft with a socket or with a piece of metal tube.
Put back the pulley and the spring washer and tighten it down. There is a special tool for that which fits into the hollow end of the shaft. I did not had that tool, so just used a normal 24 socket+bar. Using weight of the shaft and with a „sudden” tightening it already grabbed the pulley. Then I hold the pulley itself and tightened the nut.
Braves can use impact gun, I was afraid that it will ruin the new bearings.

Some further advice:
Be aware that everything inside the alternator is soft. The shaft and the fan blades can be really easily damaged.
If you would like to change the slip ring as well, you must separate the wires of the rotor and the slip ring. It is a welded connection, so a dremel will be useful there. To get the slip ring off, gently cut the slip ring into pieces and then pull it off from the shaft. The shaft itself below the slip ring is really small in diameter, so be careful not to bend it. If you could get the old slip ring off, you just have to slide the new one on and solder it to the wires. Be aware that it fits only one way on the shaft, and if you mess it up, you will only notice it when it is too late and it can be taken off only by damaging it.

This how the slip ring looks like:


So that’s all folks! :)
I hope that it will be useful for someone.

1998 S70 Alternator bearing change

1998 Volvo S70 Overview

Volvo’s best seller in North America underwent a couple of very noticeable changes for the 1998 model year. Foremost was a new and sleeker name, as the 850 became the S70. And even if you tried you couldn’t overlook the other obvious difference: a loss of some of its trademark boxiness.
Yes, some of those corners have been rounded out a bit, but it’s not as if that has had a negative effect on its outstanding reputation for safety (in fact those slightly more aerodynamic edges might even result in a mileage boost).

The sedan formerly known as the 850 may have itself a new moniker, but its purpose remains the same: to deliver its occupants to their destination safely and comfortably. The 1998 Volvo S70 adds another adverb to that list: stylishly. That’s right – the famously boxy buggy has undergone a makeover, losing some of its squareness both literally and figuratively, as the Ford-run edition of Volvo delved into a new marketing turn that lets style ride in the front seat with safety. In other words, “Sure, we’re the safest, but we’re darned good-looking, too.”

Some 1998 S70 owners feel that the debut year was not snag-free. Generally with Volvos the consensus is the car is wonderful until you get the repair bill, but this time around there’s a camp where the feeling is that the Swedes should have done a bit more homework. One user proclaimed, “They should have left the 850 alone for a few more years.” Several complained about numerous problems and frequent repairs, aggravated by the fact that nearly all replacement parts are only available through the dealer.

But you can’t please all of the people all of the time, and certainly many a 1998 Volvo S70 driver conducts his commute with a smile. This is the result of rolling down the road enjoying truly exceptional handling and performance while feeling confident that this vehicle, which received stellar ratings in NHTSA crash tests, will protect you should something go awry. Plus the Narcissus in every driver loves knowing that in this car he looks great doing it, too. One user commented: this car is made for the highway. You can maximize your fun by going for the 5-speed manual.
Fuel economy is quite good, with a well-tuned 2.4-liter engine yielding about 20 city and 28 highway. Air-conditioning, power windows and locks, and ABS are standard equipment. The 1998 S70 earned 4 stars from J.D. Power in the style, mechanical quality, and creature comforts categories, although it was given a meager 2 for mechanical dependability. All other categories were in the middle range.


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