XC90 V8 Alternator Replacement

On 20120208 at 92,415 miles, I got a red triangle indicator and a “POWER SYSTEM SERVICE URGENT” message in the message center, along with the battery warning icon illuminated in the idiot-light panel on the right, followed by a MIL/CEL shortly after:

  

Since I was already close to home, I shut off all the accessories like air-con, lights, and radio and drove home. When I got home, I checked the battery voltage with a digital multimeter and found the battery was only showing 10v so I quickly hooked up a battery charger and did a little research. It turns out the alternator on the V8 model is prone to failure.

Unfortunately, it looks like this alternator is specifically made for this engine, the Volvo B8444S which is only used in the Volvo S80, XC90, and Noble M600. Production volume is low, so it’s difficult to find a replacement that is reasonably priced. My first call was to the local Volvo dealer to see how much a new one cost. Unsurprisingly it was near $800 for a new alternator from the dealership, and with the additional 3 hours of labor to change it, brings the total cost of swapping out an alternator to a whopping $1300. Not happening.

The stock unit is made by Bosch:

  • Current output: 180 amps (there is also a 140 and 160 amp model, but the V8′s were only fitted with the 180amp model)
  • Bosch part number: AL0821X (You can substitute AL0821N for a NEW unit)
  • Volvo OEM part number: 36000791

It’s also important to note that 2003-2004 V8 model uses a self-regulating alternator where the current and voltage regulation system is built inside of the alternator unit. Starting from 2005, the regulation is controlled by the ECU. The regulators are still inside of the alternator, but the current and voltage output is now controlled by the ECU instead of internally by the alternator.

You CAN put in a 2003-2004 V8 alternator in a 2005+ V8, however you will get a red triangle warning “POWER SYSTEM SERVICE URGENT” and a battery idiot light because the ECU cannot communicate with the alternator. The alternator will continue to function normally and will charge the battery, but you will still get the warning messages. The cost difference isn’t significant, so it’s worth it just to get the 2005+ alternator and fix it correctly.

Next stop was to check common online retailers of Volvo OEM and aftermarket parts:

In the end I ordered a rebuilt Bosch alternator from BuyAutoParts.com – they called me a few minutes after my order to confirm that it would fit my car and also to add $75 for the core deposit, which will be refunded when the original bad alternator is returned.

Start by letting the car sit for at least 5 minutes since you took the key out. This allows the ECM to store any running parameters and go into a safe state to disconnect the power. Some impatient or well-meaning garages have damaged or destroyed ECM’s by removing the battery cable too quickly after shutting off the engine! Don’t take the risk, just go have a drink, use the bathroom, clean the garage, whatever for 5 minutes, then go into the back and disconnect the battery! While the battery is disconnected, hook up a battery charger to the battery. This will be explained below.

Since the V8 powerplant is so crammed in the engine bay, the engineers chose to install the alternator at the bottom behind the passenger side front wheel. The first step is to remove the wheel so you can access the panel and components behind it. Make sure the vehicle is jacked up and on a secure jackstand – you can see the mounting point I used below. After the wheel is off, there are a series of plastic flange nuts that have to be taken off so the lower component cover can be removed. Remove the nuts and then remove the panel.

 

 

Here is the refurbished alternator shipped from Bosch – this particular unit was made in Hungary and has the part number AL0821X. Also attached to the alternator is a red tag that explains some warnings about installing the alternator. Interestingly, the warning says to make sure either a brand new battery is installed, or the battery is fully charged before starting the engine with the new alternator. This goes back to the fact that we connected a charger to the battery after disconnecting it from the car, right? You did put a charger on the battery, right? Right? Put a charger on the battery!

  

  

Now take a look at the hub assembly – there is an axle nut on the front that needs to be taken off. Remove this, the steering linkage connection, and the swaybar endlink connection to the hub assembly. Spray them down thoroughly with a penetrating lubricant before to make the job easier. The joints may rotate in the socket, so you might need to improvise something to take the nut off. It will also help to jack up the entire hub assembly with a floor jack to make it much easier to remove the swaybar endlink connection to the strut body.

  

  

  

With the linkages removed, it’s now time to remove the axle from the hub assembly. Make sure the ABS sensor and the brake lines are out of the way – I unbolted the bracket and tucked them away. Turn the hub assembly hard to the left all the way as if you were making a hard left turn – turn it all the way and then get a punch with a blunt point, like a socket and socket extension. Put the punch into where you removed the axle nut and hammer away to remove the axle from the hub assembly. You will need to play with the hub angle and varying the pressure on the axle to get it to pop out.

 

Before the axle will come out from the transaxle willingly, the axle bearing cradle has to be opened. It’s a lot easier than it sounds – follow the axle into the car until you come across a U-shaped piece bolted in at two opposite points. Remove the bolts, and give it a firm whack with a drift and rubber mallet and it will come off. Now, jack up the hub assembly again as if you were removing the swaybar endlink bolt, firmly grab the axle with both hands, and give it a firm tug. The axle will literally pop out of the transaxle. You will need to fidget with the hub and the axle to maneuver it out. You will be able to remove it without removing the lower ball joint, it will just take some time, and some effort to wiggle it out. Remove the jack that’s holding up the hub assembly.

  

  

See the alternator hidden up there? Before you remove the three bolts, you will need to disconnect the wiring harnesses to the alternator. The alternator output positive cable was easier for me to remove by getting a small 1/4 inch socket wrench from under the car. Reach up from the wheel well, up behind the engine, and up over the alternator and remove the nut that holds the positive cable in and remove it. The alternator field wiring was easier for me to remove from the top of the car – you will need to remove the upper engine mount assembly that goes between the strut towers, the rear plastic engine cover, and the plastic accessory belt cover. Beware – on the accessory belt cover, there are two Torx screws holding it in. With the plastic covers off,  you can reach behind the engine from the top of the engine bay, reach the alternator, and disconnect the field wiring.

Now we will need to remove the accessory belt around the alternator. You can do this one of two ways – you can do it from under the car, pull the accessory cable towards you, and put a socket on the crank pulley, and turn the crank pulley clockwise – this will force the belt to derail over the alternator pulley and pop it off. The recommended way is to get a long socket wrench like a breaker bar, put a 19mm socket on it, and attach that to the welded-on nut on the belt tensioner from the top of the engine bay. You will need to pull on this towards the front of the car firmly for about 40 seconds and slowly the belt tensioner will release and you can slip the belt off the top idler pulley. Take your time on this! If you exceed 177 lb-ft on the tensioner, you can damage it so just do it slowly!

 

It’s just a matter of unbolting the three bolts (two lower, one upper) that hold the alternator to the engine block and dropping it out! This was what took by far the longest for me – it’s a tight squeeze to get the alternator out of this little hole you made. Get the alternator out, and turn it around. You need to remove the heatshield on the back of the old alternator and install it on the back of the new alternator, reusing the Torx mounting screws.

  

Now, you’ll need to negotiate the new alternator back into the engine bay and bolt it up. The alternator alone is nearly 20lb – it will be extremely beneficial to have someone hold it while you navigate the mounting bolts in – be very careful not to gouge or strip these threads! The engine block that you are bolting the alternator onto is made of aluminum! Once the alternator is bolted up, install the output positive cable and the field cable – again for me it was easier to do the output positive cable from the bottom, and the field cable from the top. Get yourself a beer, you’re halfway done!

Get your 19mm socket and long socket wrench again. Install the alternator belt around all the accessories except the top idler pulley. From the top of the engine bay, put the socket wrench on the tensioer, and give it a firm and steady pull for about 40 seconds to a full minute. The tensioer will release and allow you to slip the belt over the upper idler pulley. I was able to do this with one hand in a few tries, but it would probably be easier to do with a helper. Again, do not exceed 177 lb-ft on the tensioer pre-loading bolt!

Now, jack up the hub assembly again and install the axle back into the transaxle – putting it back in required some wiggling of the axle, the hub assembly, and adjusting the height with the jack. Make sure the bearing surface is clean and then bolt the bearing cradle back up. Now comes the tricky part – turn the hub assembly to the hard left again and get a long prybar or long thick screwdriver and brace it against the lower A-arm, and the other end near the ABS sensor teeth. With enough careful prying, and fine adjustments with a large hammer, you CAN get the axle back into the hub assembly without removing the lower ball joint. Trust me on this, it is possible. I had no tools available to remove the lower ball joint so this was the only option I had!

 

With the axle back in place and the hub assembly still jacked up, connect the swaybar endlink back to the strut housting and lower the hub assembly. Reinstall the axle bolt and the steering linkage. I found I didn’t need to hold the center bolt section on tightening. Re-install the ABS sensor line and brake line brackets.

   

Now, clean off the engine bay and reconnect the battery. Double check that the belt is installed correctly and the alternator is wired correctly, and the engine bay is free and clear of tools, rags, and foreign objects. Start the car and check the voltage across the positive junction and a ground – you should get above 14 volts now! I was able to get 14.29 volts. Yay! The alternator works! Shut off the engine before it gets warm so you can work in the engine bay without getting burned and so the radiator fan doesn’t run continuously.  You can now install the wheel, the accessory belt cover, the rear engine cover, and the upper engine mount. Pat yourself on the back well done, and soak in the feeling that you didn’t have to pay Volvo over $1000 to fix the car. Enjoy! The fact that you disconnected the battery cable will clear any CEL/MIL. Please leave any questions or comments below!

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8 Comments

  1. AJ says:

    Partner, VIDA has nothing on you. This is a most helpful posting that is about to save me cash. Many thanks to you.

  2. clay johnson says:

    volvo has a new protector & air duct to help cool the alternator. part # 30795212, 30795440

  3. Jacob Beale says:

    Thanks for the helpful write up. Took mine to independent shop and they wanted $1300 for new alternator and install. Dealer wanted $1200. Was able to get remanufactured for $280 and even though took me a while spread over 3 days, I got it done. And it works! Saved me over $1000. Never would have been able to do it without your help. Best writeup I’ve seen of ANY Volvo repair. And great pics. Many, Many, Many thanks.

  4. Chicago Ed says:

    I spent most of today wrestling this alternator out of my 07 and have a few opinions. 1) getting the drivetrain parts out of the way was certainly the easy part-and I did have to jack the brake disk-and that’s a tricky affair with the volvo scissors jack. Be careful not to bump it or it will drop hard against you as it’s spring loaded-and be careful not to puncture cv joint! Removing anything on top of alternator required getting on top of engine-though the top bolt was last to be removed and required really long extensions from underside with universal ext. Coolant lines assembly had to be unbolted from engine block. The tensioner was another story-not sure applying pressure for a minute released it adequately. Would help to know whether the 9mm allen that appears to be the pivot point needs loosening-and I’ll figure that out when I install. Oh-and there is a belt diagram on another site which helps a bit. What also would help is using a 19mm socket which is 2″ deep as a 1.5″ deep socket doesn’t quite have clearance from the coolant line coming out of the manifold on top of the block. I do not look forward to this next wrestling match of installing-but when I start doing the math-it definitely feels like I’m earning it the hard way.

  5. Chicago Ed says:

    Installation complete-and prior to install-I found I could get some slack from the undercarriage to the Fuel lines I mistakenly thought were coolant lines-and then could move the stainless tube assembly up-and mostly out of the way from on top by removing the solid black plastic shielded tubes out of the holders. Getting the bolts in worked best by starting two on bottom and getting the alternator about 1/4″ from the block and then lifting it a little to get top bolt started. You have a jack point on the A arm-and you need to lift adequately to accommodate the cv joint to get high enough to feed it level into the tranny. I then lowered it again to line up the feed in the wheel axle. The spring loaded tensioner released exactly as you described. Not the best mechanic project for someone out of practice-but very satisfying-though I have to get a tap to fix the threads my center punch mangled where the axle bolt goes. Though I put the wheel back on this allows for more battery charging. The message light is gone and she’s 99% done! Thanks for posting!

  6. Michael Gayle says:

    I have the same problem. Mechanic put in a Bosch computer controlled rebuilt alternator and the light won’t go out. New battery that went dead, but supposedly is charged. HELP?!?

    Mike

  7. dave says:

    just wondering if you could tell me how to get plastic cap off battery cable terminal & is it a nut that holds cable or something else that holds it. AS FOR THE FIELD EFFECT WIRE ITS JUST A REGULAR TYPE PUSH IN COMPUTER PLUG RIGHT THANKS ANDREW DAVE

  8. Yue Fan says:

    Thanks, Andrew! Great work and documentation.

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