First consult this video to get familiarized with the process:
https://www.youtube.com/watch?v=hszyGlMaofE
That video, and most other descriptions, suggests to remove the AC compressor and drop the alternator out the bottom of the car. I did NOT do it that way. I'm not sure if my car was missing things that made it easier to remove from the top, but I was able to remove the alternator from the top without removing the AC compressor. I also did not need to remove any turbo tube plumbing as was done in that video. To clarify, I was working on a 2000 VW Jetta TDI. It has a manual transmission and therefore requires the 120 ampere alternator. The 90 ampere alternator is used on the automatic transmission TDI cars.
- Jack the front passenger side and place a jackstand for safety.
- Disconnect your battery.
- If necessary remove the passenger side and bottom plastic engine covers to gain bottom access to the serpentine belt area. You may be able to get away without removing the bottom cover and only remove the side one. My car actually has neither.
- Remove the passenger side radiator fan. This is mounted by three Torx-30 screws. I used a 1/4" drive ratchet with a 1/4" socket and a T-30 bit. I dropped this out the bottom and this is where having the bottom engine cover off is probably helpful. If you can unplug from the top, then you can probably pull this up and out. Once the fan is out of the way place some cardboard up against the radiator protection for when you pull the alternator.
- Remove the serpentine belt. Use a 16mm end-wrench and rotate the tensioner clockwise to loosen the belt, I did this from under the car.
- Remove the belt tensioner. I worked from above to remove the 3 bolts holding this down. I used a 3/8" drive ratchet with a 13mm socket and a short extension for this. Be careful not to drop the tensioner on the ground and ding up the pulleys. Maybe put some towels or cardboard down underneath just in case.
- Disconnect the alternator power cable lug, control connector and the cable clamp. The lug is held on with a 13mm nut. The clamp has an 8mm nut on it.
- Remove the 2 bolts mounting the alternator. I used a 3/8" ratchet with a 13mm socket and no extension for this. I removed upper and lower from the top and bottom, respectively. From the bottom use a small pry lever to remove the alternator from its mounts. Then from the top work the alternator carefully up and out of the car. Work around the coolant and AC lines.
Yay its out! Now reverse the procedure for installation, cleanup and enjoy a cold one, unless you're doing this at 6am like me. ;)
My total work time was less than 2 hours, including cleanup.
https://www.youtube.com/watch?v=hszyGlMaofE
That video, and most other descriptions, suggests to remove the AC compressor and drop the alternator out the bottom of the car. I did NOT do it that way. I'm not sure if my car was missing things that made it easier to remove from the top, but I was able to remove the alternator from the top without removing the AC compressor. I also did not need to remove any turbo tube plumbing as was done in that video. To clarify, I was working on a 2000 VW Jetta TDI. It has a manual transmission and therefore requires the 120 ampere alternator. The 90 ampere alternator is used on the automatic transmission TDI cars.
- Jack the front passenger side and place a jackstand for safety.
- Disconnect your battery.
- If necessary remove the passenger side and bottom plastic engine covers to gain bottom access to the serpentine belt area. You may be able to get away without removing the bottom cover and only remove the side one. My car actually has neither.
- Remove the passenger side radiator fan. This is mounted by three Torx-30 screws. I used a 1/4" drive ratchet with a 1/4" socket and a T-30 bit. I dropped this out the bottom and this is where having the bottom engine cover off is probably helpful. If you can unplug from the top, then you can probably pull this up and out. Once the fan is out of the way place some cardboard up against the radiator protection for when you pull the alternator.
- Remove the serpentine belt. Use a 16mm end-wrench and rotate the tensioner clockwise to loosen the belt, I did this from under the car.
- Remove the belt tensioner. I worked from above to remove the 3 bolts holding this down. I used a 3/8" drive ratchet with a 13mm socket and a short extension for this. Be careful not to drop the tensioner on the ground and ding up the pulleys. Maybe put some towels or cardboard down underneath just in case.
- Disconnect the alternator power cable lug, control connector and the cable clamp. The lug is held on with a 13mm nut. The clamp has an 8mm nut on it.
- Remove the 2 bolts mounting the alternator. I used a 3/8" ratchet with a 13mm socket and no extension for this. I removed upper and lower from the top and bottom, respectively. From the bottom use a small pry lever to remove the alternator from its mounts. Then from the top work the alternator carefully up and out of the car. Work around the coolant and AC lines.
Yay its out! Now reverse the procedure for installation, cleanup and enjoy a cold one, unless you're doing this at 6am like me. ;)
My total work time was less than 2 hours, including cleanup.