(approx) 2 Hours
Light to Moderate mechanical skill required.
- Customer Submitted:
- BBK Underdrive Pulleys - Installation Instructions
Features, Description, Reviews, Q&A, Specs & Installation
Technical Note: This pulley system requires the use of a 6-rib 96" length serpentine belt.
Fitment: 1994 1995 1996 1997 1998 Details
CA Residents: WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov
August 22, 2018
This gives u a few horses cheap !! It was super easy to install and I love the results!!Helpful (3)
August 24, 2017
Best bang for the buck
I love these pulleys really gives off a nice look. And you can feel the difference instantly.Helpful (4)
June 01, 2017
BBK under drive kit
Easy to install if you have air tools or impact drill.Helpful (4)
February 18, 2017
Fit good and looks good don't notice a huge difference but notice a little differenceHelpful (4)
August 23, 2016
I feel the power difference right away!. She really accelerates at a faster rate. When you hit the gas pedal just lean back and watch the RPMS climb!!! great product for my v6 mustang I really need to get a tune so i can see what she is really made ofHelpful (4)
December 13, 2015
Good place to start.
These BBK Underdrive pulleys are a very good place to start modding. I put these in my 97 3.8L, and the gains were immediate; acceleration is much more responsive now! I was able to install these within 2 hours, however you will have to have an impact wrench to do it at home.Helpful (7)
January 05, 2015
No Shake, adds small ponys
Received this as a Christmas gift after i had been adding things to my build list. Was a bit nervous about the install because i didn't have an impact wrench. Took the underdrive pulley off after following some of the instructions given in the reviews. I had a bit of confusion at first because i was looking at the detailed instruction list that was provided by AM compared to the factory install. What i found was that it was easier than even the factory install shows (no real need to loosen/remove the water-pump pulley screws since you aren't replacing that pulley with this kit) and much easier than the detailed breakdown from AM customer showing how to remove the fan and such is unnecessary since it is wanting you to also remove the balancer as well (which needs the balancer puller, and is why you need the extra room). The detailed walk-through is a good breakdown and has a lot of pictures, so if you are visual like i am it really helped explain some things. However, you can skip everything that doesn't have to do with the either the alternator or under drive pulley itself. In short I disconnected the battery then used 13mm sockets to remove the under-drive pulley (loosen those bolts with the belt still on, then remove the belt and remove the bolts fully). Then either use an air impact wrench to remove the alternator pulley or like i did, take the alternator off (super easy in the v6 i think it needed 10mm and a 15mm for the two bolts and then just undo the wiring. there's a battery connector that was the only hand contortion i had to do with maybe a 7mm on the back of the alternator) and take it to an O'reilly's or auto parts store. They can swap the pulleys in about 2 minutes. Take the alternator back and bolt it back into place. The underdrive pulley goes on easy, then put the belt on. I used a 96 1/4" belt which fit perfect on my '98. Cake walk. I haven't had it on for too long but first impressions are it adds some small horsepower. I haven't got any official calculations but just noticing the tendencies it pulls a little harder at low end and slightly more at mid range. The other delightful change was the removal of engine shake. This was noticeable straight away for me as my idling was normally pretty rough. Now it is quiet and as still as a brand new car and I'm quite impressed. I have not had time to calculate MPGs but i will update if I notice something significant. One detraction I am having though is a sharp whine that is now coming from the engine compartment. I am guessing that it is the alternator cranking a bit more than normal. I have this and heated seats (convertible drive time extended by a month and a half :)) adding to additional power draw so i'm not sure if its that or something else. I'll have to inspect it later. I have near 170k on my car so it might be time to replace the alternator anyways. Looking to get a 150volt to be on the safe side for power needs. Otherwise a super easy bolt on that seems to have some good returns. For less than $100 this thing is worth every penny just to remove the engine shake, everything else is icing.Helpful (5)
September 10, 2014
These pulleys have already paid for themselves already. The increase in my MPG is very noticeable and the slight power increase is too...well worth the $90 price. Did not take much time to install them either. It really helps to have air tools...Helpful (4)
March 06, 2014
best bang for your buck
Very easy to install. The only thing I would suggest is an impack for the alternator bolt. I tried the 96" like it suggested but their was way to much play so I went down to a 92.3" belt which has worked perfectly. Idle smoother and quieter. The throttle response was way better. It didn't feel slugish off the line anymore. Worth the money.Helpful (6)
May 16, 2013
Great for the money
Installation was very easy and quick. It took me less than 30 minutes. Idle is much smoother now and you can tell a good difference in throttle response, plus it's a little quicker in the 3k to 5k rpm range. Definitely happy with the product and would recommend to anyoneHelpful (4)
Where can I get the proper belt to be able to use these?
What is the main reason that this underdrive pulley will not fit a 2004 v6 mustang? Is it the bolt pattern?
This is specific to the 94-98 V6. They do share the 3.8 engine with the 99-04 models, however, changes we made to them.
What is the exact weight of this item?
The BBK Underdrive Pulleys will weigh in at 1.85 lbs.
Hello I live in California will this affect smog in any way? Also can you give me a link to a belt that’ll fit Thanks
We do not have a listed CARB number for this product and would suggest speaking directly to your local emissions board or wherever you have your inspection preformed in order to best verify. In terms a belt that will fit this is going to require the use of a 6-rib 96" length serpentine belt.
do you have to get a tune after install with these?
The BBK Underdrive Pulleys will not require a tune.
Unfortunately we do not offer an Underdrive Pulley Kit for a 2001 V6. We are constantly getting new items on our website. So keep checking back to our site in case we get one in the future!
The BBK Underdrive Pulleys (94-98 V6) will require the use of a 6-rib 96" length serpentine belt for the proper use.
These pulleys will have nothing to with the power output of the alternator for your sound system. 1400w amp is really nothing to worry about. Get a capacitor or higher output alternator for more power if you desire.
Unfortunately, these underdrive pulleys are only designed to fit the 1994-1998 V6 Mustangs and are not compatible with the 1999-2004 V6.
(approx) 2 Hours
Light to Moderate mechanical skill required.
What's in the Box
|Crank Pulley:||Piggyback||SFI Certifited:||No|