850, 1998 S70 Alternator R & R

[timetobakethedonuts]

I wasted a lot of time removing the alternator in my 1998 S70, so I am posting some tips here. I believe this applies at least to late 850 models also, but not 1999- S70s or P2. I found no forum or video that explains it sufficiently well. There are a few ways to proceed, but after wrastling with this project for multiple extra hours, I will describe what I know works. Also, what to avoid so you don't get stuck using one of the other methods, as I did.

Tools to have:
~ Custom tool to release serpentine belt tensioner (19mm square required on the 1998)
~ 1/8" diameter by 2" long nail or screw, to hold belt tensioner in open position
~ 3/8 ratchet
~ 3/8 drive bar
~ 3/8 universal joint
~ 3/8 12mm and 13 mm DEEP sockets (I went and bought these after watching a video. Due to the dimensions of the space to be worked in these are critical to have as a standard short 3/8 extension and standard socket are too long)
~ 13 mm combination wrench
~ Good flat screwdriver or 7 mm socket to release hose clamps
~ Clean container to store 1 qt radiator fluid

IMPORTANT -
~ Make a diagram, showing the routing of the serpentine belt

The bolts of the alternator and PS pump are hard to access and hoses block access, so you needs to get some things out of the way.
~ Remove the negative battery terminal from the battery. Make sure it is disconnected and will remain so.
~ Loosen the petcock at L-F of car through hole in splash shield, and drain 1 qt liquid into a clean container. Tighten petcock.
~ Remove upper radiator hose by loosening the two hose clamps.
~ Remove the air guide that goes from the top rear of the radiator to the electronic box against the RF fender.
~ Remove the electronic box cover by prying the two metal clips with a the flat blade screwdriver and pulling upwards. This will provide needed access space to the accessory pulleys and bolts.
~ Remove the electric cable connector clamped to the D-S of the power steering reservoir assembly by gently prying back and forth with the screwdriver. Go slowly to not break the thin plastic that the metal spade bracket protrudes through.
~ Remove the dipstick, by pulling the 12 mm bolt that screws straight UP through the mounting bracket. Then pull upwards firmly to remove the tube and seal from the block. I use multiple extensions from underneath the car to do this.
~ Insert the belt tensioner tool, and with pin in right hand use handle, wrench, etc to turn tensioner clockwise. When indexing holes are aligned (use a flashlight to locate these in a dry run before torqueing tensioner), press pin in and release wrench.
~ Remove the serpentine belt, starting by sliding off the smooth idler pulley. Remove it from the car.

An aside -
OK, the prep work I assumed was needed is done at this point. Note however that my first attempt failed miserably. I believed that by removing four bolts, three of which go through bosses on the alternator, and one of which solely mounts the PS Pump and its cage, that the entire PS assembly and alternator could be pulled out, with the PS Pump hoses left connected. What happened however, was that the PS cage would not release from the alternator. Not realizing that loosening the bolts that mount the PS Pump to the cage would loosen the side plates of the cage and allow it to release from the alternator, I stuck the worst possible bolt that mounts the alternator back in. It goes through a hole in the PS Pump cage, and the cage was moved out of place in trying to wrench it out, so that I could no longer get it back in position to remove that bolt. It was at this point that out of desperation I discovered how to get the cage out, exposing the alternator. Thus my recommended method that follows.

Given the problems encountered above, I advise getting the PS Pump and cage out of the way, exposing the alternator for its removal. But we will also remove all the mounting bolts for the alternator. These bolts all have a 12 mm head, and nuts when present are 13 mm.

~ Loosen a bolt at the DS bottom rear of the alternator, which goes into a nut welded to the PS cage plate. This is very hard to access, and until loosened you won't be able to even see the head of it. First feel around with your index finger to determine its location. Use the deep 12 mm socket
~ Loosen a bolt that is recessed though the P-S of the PS Pump cage plate, while holding the nut with a 13 mm box or socket.
~ Loosen a bolt just above the last bolt removed, while holding the nut with a 13 mm wrench.
~ Loosen a bolt to the bottom right of the PS Pump pulley, which goes into a nut welded to the PS Pump plate.
~ There are three bolts accessed through holes in the PS pulley, one bottom right, one bottom left, and one top left of center. These bolts will only be loosened. Loosen the top left bolt 3 to 4 turns. Loosen the bolts at the bottom 5 more turns but do not remove them. By loosening these bolts, the PS Pump and cage assembly will release from the bosses on the alternator.
~ On the rear of the alternator, pull off the single spade connector, pry off the plastic cap protecting the positive terminal and use a 13mm socket to remove the red alternator lead.
~ Remove the belt tensioner by pulling the two 12 mm x 30 mm long bolts that attach it to the PS Pump cage plate.
~ Remove the long 4 bolts (and nuts where present) loosened in the first four steps. NOTE WHICH LOCATION EACH CAME FROM.
~ Loosen the long bolt that runs on the top P-S of the PS Pump cage assembly, but do not remove it.
~ Lift the PS Pump cage upwards and to the right (towards the D-S), and flex the PS hoses so that the pump assembly can rest near the intake

Now the alternator should be free to be removed.

In my case, I didn't know if or how the cage would release, so I siphoned the PS fluid into a lean container, and removed the pressure and return lines from the reservoir. This allowed me to remove the entire PS pump reservoir and cage. This is NOT necessary. After performing the above procedure, patiently wiggle the cage and pump, which extends down to and mounts the smooth idler pulley, until everything clears, and swing this assembly over towards and on top of the intake.

That's "all" it takes. If I knew the above, it would have saved me hours of time wasted.

Reinstalling
~ First I would insert that hidden bolt, so the threads are flush with P-S end of the alternator boss. This will hold it, and allow for the PS Pump cage to be dropped in.
~ Swing down and drop the PS Pump and cage in, and get it aligned over the bosses of the alternator.
~ Plug in spade connector to alternator, and reinstall red lead and pop in protective cap.
~ Insert the three additional long bolts and tighten loosely
~ Get that hidden bolt threaded into the PS Pump cage plate and tighten it first
~ Tighten the three mounting bolts of the PS Pump, through the holes of the PS Pump pulley
~ Tighten three remaining long bolts
~ Reinstall tensioner
~ Reinstall serpentine belt Release tensioner and remove tool.
~ Reinstall air box top, and air guide tube to radiator
~ Carefully snap electrical connector back onto metal spade clip on D-S of PS Pump cage plate
~ Reinstall dip stick tube
~ Reinstall top radiator hose and tighten clamps
~ Reinstall saved radiator fluid

Start the car, check your voltage with a DVM, and check for leaks

[RedBrickCollector]

I've read somewhere that the tensioner is designed to take a standard 3/4ths socket. I haven't tried it myself but this may improve the guide. I'm invested as I may need to pull mine out if my low voltage isn't just wiring related.

[timetobakethedonuts]

I've read somewhere that the tensioner is designed to take a standard 3/4ths socket. I haven't tried it myself but this may improve the guide. I'm invested as I may need to pull mine out if my low voltage isn't just wiring related.

I read the opposite comment somewhere that a 3/4 drive tool would not fit. Since I do not have a 3/4" drive bar or ratchet, I could not test this. I did not want to take any chances since there was no way to do a precision trial fit. I ground a few thousandths in each direction off 3/4" square steel stock I happened to have on hand, until a caliper showed 19mm. Then I hacksawed it off to roughly 1-1/8" length.

People use all kinds of solutions - I was about to try: square nut with a bolt and second nut to lock the bolt with the square nut. Mine is good old fashioned solid steel, with a large crescent wrench to torque it.

Regarding your low voltage, mine was really low - under 12 V. New alternator is 13.7 at idle.

The only thing my post adds to the posts and videos I have seen is, releasing the sides of the PS Pump cage by loosening the three bolts that attach the pump to the cage plate, and the top long bolt perpendicular to those, is critical, so that it lifts right off and can be placed back on the alternator.

[abscate]

I once spent a good hour trying to figure out how that cage went back on a 1998, just staring at the pieces. I, too, struggled to find good documentation on it.

[yanga001]

I normally removed the ECU,TCU, and box and put paper towels over the connectors. This gives you much more access to the tensioner, the bolts for the power steering, and makes it easier to get the alternator out. Takes about 5 minutes to pull and makes your life a lot easier.

[RedBrickCollector]

Regarding your low voltage, mine was really low - under 12 V. New alternator is 13.7 at idle.

I guess I won't be prioritizing this then, as I'm right around there, though it only climbs to around 14 flat under load

[timetobakethedonuts]

I normally removed the ECU,TCU, and box and put paper towels over the connectors. This gives you much more access to the tensioner, the bolts for the power steering, and makes it easier to get the alternator out. Takes about 5 minutes to pull and makes your life a lot easier.

I am a also big fan of making things easier. I had to pull the new alternator last night (the new pulley is offset 50 thousandths from the old - it works but would prematurely wear the belt), and the procedure above worked like a charm. Took me about an hour to get it apart. The specific items that you mentioned, for me, were all not a problem. This could be because of the deep 12 mm socket I used - it allows a ratchet or bar to be used on all of the bolt heads that need to be accessed. As I mentioned in the post, a standard short 3/8" extension and standard socket are longer than the deep socket, and would not work on the accessory pulley side. My guess is one would have to remove the box as you did without a deep socket. With the tool I made, the tensioner is easily accessed. The big Easy button for me personally was finding out the cage loosens completely, making removal and installation a snap.

[timetobakethedonuts]

I once spent a good hour trying to figure out how that cage went back on a 1998, just staring at the pieces. I, too, struggled to find good documentation on it.

Kudos to you. I think I complained for at least an hour, and searched for info online for at least two more. I should have taken a good look, like you did, at what was in front of me. A wise man once told me, work smarter not harder. I seem to often take the latter approach.

[P80GLT]

3/4" square will fit into the tensioner aperture, unfortunately there is not enough clearance to get it in when the tensioner is fitted to the car as it fouls on the ECU box. My work-around was to take a sump drain plug which has a 19mm body and file two corners off to make a hexagon fit into a square hole. 19mm long reach spanner and it works a treat

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[erikv11]

We used to get "hey-look-this-is-the-best-and-cheapest-p80-serp-tensioner-tool-ever" posts cropping up pretty regularly about every 3-6 months, nice to see one again!

a couple classics
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viewtopic.php?t=60913