Alternator DIY

[JDriver1.8t]

I upgraded from a 90 amp 1.8t alternator to a 120 amp VR6 alternator. (not by choice, I killed my original one)

I could not find any info, so here it is.
A shop will charge 1.5-2.0 hours of labor for this job.
I did it in 2 hours. If I had to do it again, I would have it done in 45 minutes.
advice:-read all of this before you start. Duh. Some steps you can change the order of as you see fit, to make things easier to reach.

Tools: (most of them at least)
8mm socket
10mm socket
13mm socket, deep and shallow
13mm wrench (standard and ratched if you have it)
16mm wrench
1'', 3'', 6'' extensions are usefull, but not required
5mm allen wrench or socket
flat head screw driver
8'' pry bar
2- 16'' bungee cords
rag

Parts:
new alternator
throttle body gasket (if you tear yours)

This is what it will look like.

1. Start by disconnecting the battery.

2. That is the tensioner. Use a 16mm wrench, pull towards the front of the car to relieve tension from the belt, and slide the belt off of the alternator pulley.

3. Use the 8mm socket to remove the clamp on the pipe leading to the SMIC. Pull the pipe off, and put the clamp aside. I also unclipped the headlight plugs.

4. Then any combination of the 13mm tools to remove the tensioner. There are three bolts, located in a triangular fasion, near the top of it. Two of these bolt go through a bracket first.

The top bolt is cut out of this picture.

5. Next, you will start to move things to make room for the alternator to fit out. I started by removing the coolant feed pump (i think) for the turbo. It is bolted to the radiator by two 10mm bolts. I bungeed it up on top of the intake manifold.

Then I bungeed the SMIC pipe out of the way. Undoing the headlight wires helps it get out of the way.
I then removed the throttle body. There is sensor/ controller that can needs to be unclipped. I set the throttle body on top of the washer jug, but left all lines attached to it. The trottle body is held on by 4 5mm allen (hex) head bolts.

6. Remove the two bolts that hold the alternator in. They are also 13mm. You can see the top bolt hole in the picture 4 above. Then take the 8'' pry bar, and pull the alternator out. Be carefull where you pry as to not damage anything else. I placed a rag over the AC compressor pulley as to not damage it during removal and install of the new alternator.

7. Undo the clips and connectors on the back of the alternator. Then slide out the alternator. You will need a 10mm for the cable holder, a small flat head for the power line cover, and 13mm for the bolt (I think that's right).

(this is the new alternator. yours will look different)
The old alternator:

8. Reattach the wires to the alternator.
9. Put in two 13mm bolts that hold alternator in place. Tighten well.
10. Put back on tensioner. Remember, the bracket goes on the outside of the tensioner.
11- done. These can be in any order. They are putting the car back together.
a. put the coolant pump back in place. 10mm nuts.
b. put back the throttle body, and attach clip. 5mm allen (hex)
c. put belt back on. Uses 16mm wrech
d. put SMIC pipe back on. uses 8mm/ flat head
e. attach headlight wire clips

accessory belt diagram

I do not have torque specs, so pay attention as you are taking bolts out.
As always, I am not responsible for anything you do to your car. Attempt this at your own risk.

Good luck.

ps. There will probably be edits as I fine tune and spell check.

Any questions or comments?



Modified by JDriver1.8t at 1:06 AM 1-21-2010

[JDriver1.8t]

not one response?
I guess I'm used to the MK4 forums.

[jazzblue20th2083]

nice little diy.

[JDriver1.8t]

[jazzblue20th2083]

np

[Mohudsolo]

Interesting, an actual picture of the coolant pump that several people swear does not exist and other's claim is only on automatic cars. It looks like it really does, and is on at least one 6-speed car. Looks like a decent writeup and pics that I hope to never need except at part of changing timing belt.

So, how did you toast the alternator anyway or did I miss that part?

[Gr8Scott95]

Quote, originally posted by Mohudsolo »

So, how did you toast the alternator anyway or did I miss that part?

It has something to do with the 4th line in his sig.

[v-dub-u]

Could this write up allow me to replace my surpintine belt ? Mine just busted off, only 4 day's after my timing kit was replaced.

It shows the diagram on how the belt should fit, my question is how hard it is to get that damn belt on in the first place in that tight of a spot?

[Seanathan]

Nice writeup man Its always good to see more DIY's in this forum. Speaking of me and some others have added alot recently. Some moderator needs to update the FAQ/DIY thread uptop

[Shamrock]

Quote, originally posted by JDriver1.8t »

I noticed your sig said 1 farad cap., I thought that sounded reallly high considering Motors your take microfarads, So I did alittle math and serachin in my text book and online and realized that having that probrably isnt the best thing for your car and could of caused the problem with your alternator do to a potential current spike on the capacitor. Just to let you know incase you werent aware

[djbrand1]

bump from the past. So is the Vr6 120 amp alternator a direct swap with the 1.8t's 90(?) amp one. In other posts I thought a different bracket is needed?

[trbochrgm02]

its a direct swap. i just did mine a few months back.

[Varooom]

I did this diy on my golf, and instead of paying the dealer $450 for a new alt, I bought a volt reg/brush pack for $35, popped that in and was good to go. been working for the last 35,000 miles.

[Varooom]

I did this diy on my golf, and instead of paying the dealer $450 for a new alt, I bought a volt reg/brush pack for $35, popped that in and was good to go. been working for the last 35,000 miles.

[vwgti4]

the brush reg kit bumps the alternator to 120 amp output?

Quote, originally posted by Varooom »

I did this diy on my golf, and instead of paying the dealer $450 for a new alt, I bought a volt reg/brush pack for $35, popped that in and was good to go. been working for the last 35,000 miles.

[20v_boost]

Where did you find the voltage regulator / brush kit?

[801pete]

Thats an interesting after run coolant pump. My brothers 337 definantly doesn't have it. I have seen some cars around here which could use one...

[bcruze]

Can you please fix/rehost the images? If that isn't possible, can I get them emailed to me? Thanks!

[skatingzooyork]

Quote, originally posted by bcruze »

Can you please fix/rehost the images? If that isn't possible, can I get them emailed to me? Thanks!

x2

[bcruze]

Bueller?

[ANYTHING08]

you didn't have any problems getting the new alternator back in? I just got a new one and I can't seem to push hard enough to get the holes lined up. And I can't use a pry bar for this part. lol

[jwcma]

Quote, originally posted by Mohudsolo »

Interesting, an actual picture of the coolant pump that several people swear does not exist and other's claim is only on automatic cars. It looks like it really does, and is on at least one 6-speed car.

How do you know it's a 6spd tranny? It's bulkier than I imagined, but I still wish my car had one!

[jwcma]

Good job on the writeup

How much was the alternator? Are both versions about the same price?

[dirrtymk4]

Awesome, i am by no means mechanically competent, but you made it easy, took me about 2 hours as well. cheers

[txrktman]

Can't thank you enough for the instructions and great photos. Stranded 100 miles from home, I changed this our in a parking lot in LaGrange Texas late at night. I accessed your post from my laptop by tying into an unsecured wireless internet connection (how lucky is that?). Great job, and thanks again!!!

[freeborder]

awesome diy thanks im going to use it tomorrow my alt died i was just wandering how many miles did yours have when it died?

[blazerpounds]

i dont understand how this took you guys 2 hours. I did mine in under 30 minutes.

[robingohtt]

noob question..

what are the benefits to upgrading to a VR6 alternator? anybody got the part code?

can I still use my stock battery?

any uni program issues?

thanks

[robingohtt]

anybody got the answers?

[robingohtt]

bump

[burbleburble]

Quote, originally posted by robingohtt »

noob question.. what are the benefits to upgrading to a VR6 alternator? anybody got the part code? can I still use my stock battery? any uni program issues? thanks

benefits are you have an extra 30 amps, helpful if you have extra stuff drawing a load. i have one on my revo'd beetle, you can use it without issue. it has the same bolt pattern and mounts in the exact same place as a 90 amp.

[robingohtt]

so I gather I can still use the stock Votage batt (12V?)

[robingohtt]

bump on if I can still use the stock voltage battery?

[themachasy]

Quote, originally posted by robingohtt »

bump on if I can still use the stock voltage battery?

Yes, more amperage doesn't affect the voltage, drop in upgrade no mods needed.

[robingohtt]

thanks!

anybody got the part code?