UUC Under Drive Pulley Set DIY (instructions & pictures)

Here is the install of my UUC Under Drive Pulley Set (details here). UUC includes a set of instructions that are rather good but not perfect.

** Use this at your own risk **
There are several different variations depending on what tensioner you have, if you have manual or auto, etc. This is a general GUIDELINE, you will probably have some differences for your own install. For reference I have an 01/01 production 2001 330i sport manual.

1. Find the torque screw on the left side of the radiator and remove it. - I have an aftermarket intake so I don't have any of the standard air box ducts on the front. If you have this in place you need to remove that first.


2. Remove the plastic pin from the other side of the radiator. I have a cool screwdriver pry tool that I used.


3. Remove the wiring connectors and slip the wires out of the holder on the fan.


4. Pull the fan up and out.


5. Loosen the 4 10mm bolts on the water pump (while the belt is still on).


6. Loosen the 3 13mm bolts on the power steering pump (while the belt is still on).


7. Remove the cap on the A/C belt tensioner.


8. Use a torque socket to twist the tensioner to relieve tension on the belt. While the tension is off the belt slip it over the pulleys and remove it.


9. Remove the cap on the main belt tensioner.


10. Use an 8mm allen socket to twist the tensioner to relieve tension on the belt. This takes a lot more force than expected. I had to use a pipe on the end of the ratchet. While the tension is off the belt slip it over the pulleys and remove it.

11. With the belt off you can take out the 4 10mm bolts for the water pump and remove pulley wheels. My water pump pulley was stuck on so I used a screw driver to pry the wheel off. I would suggest using some PB Blaster to loosen this up in advance.


12. With the pulley off you can see where I was prying with the screw driver.


13. With the pulley off you can see the difference in size.


14. I put some anti-seize on the water pump shaft so the new pulley will not stick.


15. Install the UUC Under Drive Pulley and snug up the bolts. We will tighten them more later. Notice that the four bolt holes on the pulley are not evenly spaced! If you notice this before getting two of the bolts in it will save you time and confusion.


16. Remove the 3 13mm bolts on the power steering pump and remove the pulley. Note that both stock pulley wheels are plastic and banging on them with a hammer will break them I ended up prying this pulley off with a screw driver from under the car. I would suggest soaking both pulleys with PB Blaster an hour before you want to do the install.


17. With the power steering pump pulley off you can see the difference in size.


18. Install the UUC Under Drive Pulley and snug up the bolts. We will tighten them later.

19. Reinstall the main belt. Follow the routing diagram that UUC includes. It isn't perfect but it should be enough to figure it out. Once you have the belt mostly in place use the 8mm socket and ratchet to move the belt tensioner so you can put the belt on properly. Triple check to make sure the belt is on all the pulleys properly.


20. Put the A/C belt back on. Use the torques socket to rotate the tensioner so you can get the belt on. Triple check to make sure the belt is on the pulleys properly.

21. Put the caps back on both tensioners

22. Now that the belt is on you can tighten the bolts on both pulleys. It only takes 89 inch pounds and members have broken the bolts off so be careful!

23. Reinstall the fan, put the plastic pin and torques screw back in and connect the wiring.

24. When you start up the car listen for any signs of the belt being offset or any other issues.

Nice write up, how does your car feel now compared to how it was before? This is an excelent mod to get extra power out of your motor but now at idle those componets spin at a slower speed then they used to.

Originally Posted by raptorman5174

Nice write up, how does your car feel now compared to how it was before? This is an excelent mod to get extra power out of your motor but now at idle those componets spin at a slower speed then they used to.

When I did mine only slightly tighter steering and no noticable lag with A/C on while driving. These don't gain you much if anything as all maybe a couple hp on the high side.

And BTW nice writeup Tim

Jared

so if i do this i might as well do the water pump, correct? any DIY for the water pump?

Originally Posted by AzCamel

so if i do this i might as well do the water pump, correct? any DIY for the water pump?

Not neccessary but peace of mind if you wanted to or if you didn't fell like ripping everything apart twice. I would just buy a pump to keep on hand and replace it once the ld one fails.

Jared

Great DIY. According to the Bentley manual, the water pump pulley torque should be 89 inch pounds not 16 ft-lbs.

Originally Posted by NoVaDreier

Great DIY. According to the Bentley manual, the water pump pulley torque should be 89 inch pounds not 16 ft-lbs.

I have updated the DIY with the info, thanks

QUESTION - is 16 ft-lbs = 192 in-lbs? If so that is what I was going to tq the bolts too but that seemed like way too much so I stopped. 89 in-lbs seems much more reasonable.

Tim

I did this install today, this diy was a major help. Thanks Tim

Id like to add, when removing the fan, I found it easiest to loosen the fan shroud then remove the 3 bolts holding the fan to pump assembly (theyre hard to see, and are located just under the fan blades). Once those are off the fan comes right out with some wiggling.

Also, this is for those unfamiliar with the tensioner pulley issues (I just learned all about them today). Loosening the tensioner pulley is completely dependent on whether you have a mechanical or hydraulic pulley. Figure that out first or you risk stripping bolts (I had a close call).

Ive only driven it once since then but I really dont notice any difference.

wow nice writeup....i have my uuc pulleys sitting in my basement for about a month now ...waiting for some cash to but the water pump and doing it all at once.....thanks for sharing.

Hi Tim, I have these coming to me in the mail soon.. been reading several DIY's and just read the one from www.my330i.com:

http://www.my330i.com/mod17.php#L

My question to you is this:

Do you know why he took the time to drain his coolant and remove the radiator hoses, etc?? He ended up replacing the coolant with what he drained, I am just not sure why he did this. I have pretty much the exact same car as that without the sport package, an 01 330i. Just want to know what i am getting into, as your DIY looks much easier...

thanks!

Originally Posted by PreppyR6

I did this install today, this diy was a major help. Thanks Tim

Id like to add, when removing the fan, I found it easiest to loosen the fan shroud then remove the 3 bolts holding the fan to pump assembly (theyre hard to see, and are located just under the fan blades). Once those are off the fan comes right out with some wiggling.

Also, this is for those unfamiliar with the tensioner pulley issues (I just learned all about them today). Loosening the tensioner pulley is completely dependent on whether you have a mechanical or hydraulic pulley. Figure that out first or you risk stripping bolts (I had a close call).

Ive only driven it once since then but I really dont notice any difference.

Glad I could help! From what you posted it sounds like you have an engine driven fan, do you have a step transmission?

Thanks for the tip on the tensioner as well. I updated my first post to have a bit more of a disclaimer that this will vary depending on what car/options/build date you have.

Tim

Originally Posted by trizzuth

Hi Tim, I have these coming to me in the mail soon.. been reading several DIY's and just read the one from www.my330i.com:

http://www.my330i.com/mod17.php#L

My question to you is this:

Do you know why he took the time to drain his coolant and remove the radiator hoses, etc?? He ended up replacing the coolant with what he drained, I am just not sure why he did this. I have pretty much the exact same car as that without the sport package, an 01 330i. Just want to know what i am getting into, as your DIY looks much easier...

thanks!

I replied to your PM but I have no idea. Maybe Todd can jump in here and answer your question for everyone's benefit?

Tim

Just used this DIY.....everything went smooth....got lucky with the old pulleys...they werent rusted in to bad...i used a garden pick to take out the water pump pulley couldnt find my damn long flat head screw driver....thanks!!

Tim, that was very helpful; I also have a 01 330i and was going through the same install. I got stuck with removing my fan shroud, my fan is bolted to what looks like the water pump, do you know how to take the fan off if it is engine driven? do you know if it requires a special tool or something? any help would be greatly appreciated....

Originally Posted by Cornpops

Tim, that was very helpful; I also have a 01 330i and was going through the same install. I got stuck with removing my fan shroud, my fan is bolted to what looks like the water pump, do you know how to take the fan off if it is engine driven? do you know if it requires a special tool or something? any help would be greatly appreciated....

If you have an automatic it can be bit of a pain to take it out, that nut is reverse threaded, and if you have a special tool to hold onto the waterpump pulley, it will make your life easier. Search for diy on waterpumps, lots of tips/instructions on how to remove it. I did a quick crank with a wrench and it loosened, some have posted sucess with that method,

when i was looking for the diy for my car i ran into a automatic diy pulley removal here in this form...search around youll find.

Originally Posted by Cornpops

Tim, that was very helpful; I also have a 01 330i and was going through the same install. I got stuck with removing my fan shroud, my fan is bolted to what looks like the water pump, do you know how to take the fan off if it is engine driven? do you know if it requires a special tool or something? any help would be greatly appreciated....

Thanks for the help guys

Approx. how much time did this install take?

I did mine on my manual tranny car in approx 45 minutes from start to finish, no joke. Just make sure you read the DIY over several times before starting. I was shocked at how easy it was!