Hey to all, im fairly mechanically inclined but when it comes to tearing apart a motor or something like that im a little lost. anyways im thinking about installing asp racing's underdrive pulleys (Part number ASP549920) which has an overdrive altenator pulley to charge at idle.

my question's are:

1. is it hard to remove the harmonic dampner?
2. is there anything special you need to do to make sure it stays on (if im correct this is connected to the crankshaft)
3. do you have to do anything to "balance" it or if you put it on correct does everything just fall into place?

thanks for the help
have a good one.

 

Not sure I can be of any help. But I would REALLY like to know how this turns out performance wise. I was considering doing this to my truck several months ago but chickened out.

 

To remove the existing crank bolt, you'll need a pretty good impact...they can be a bear. I wouldn't recommend a breaker bar as I've seen this break the crank bolt head clean off. If that happens - you have big troubles. Use an impact. A big one.

Once the crank bolt is out, to remove the harmonic, you need a 3 jaw puller...you can rent one (loaner) from an auto parts store if need be.

When you put the underdrive pulley on, you just need to get it started, and then torque it down with the OLD crank bolt until it basically bottoms out. Then take the old one out, and put the new one in. That's all that is needed.

A new crank bolt is essential ($10.00± from the dealer). They're stretch-to-yield and not resuseable.

As far as noticing a difference, in all honestly it's minimal compared to other mods like a cam, torque converter, etc. For the SOTP feel, it's one of the more pricey "lluxury" mods.

Do you have any other mods done?

 

the only thing i noticed when i had them was my lights flickering and a low charge at idle. it's not a bad mod to do if you are running out of other bolt ons imho.

 

Yea i have a K&N 63 Series air charger, Hypertech max energy 87 octane tune, 40 series flowmasters. my truck is still under warrenty so i dont want to do anything to cause that to not be upheld plus i want a good daily driver with some resemblance of mpg. i should have kept my camaro and bought the z-71 but you live and learn.

i love the power of my 5.3 its enough for me to haul my polaris 800 but i think the gearing is **** on it. 3.42 gears blow, as for increased mileage from 3.73 i think that was all in GM's head.

my dad had a stock long bed 2003 Z-71 with the 5.3 and the only difference between my 06(when stock)and his 03is mine is a "flex fuel" motor and i have electricfans and my 3.42 vs his 3.73 and he was getting 14-15mpg while i was getting only 12.5mpg (same kind of granny driving).

anyways sorry about the long winded story here but im thinking of just replacing my gears with 3.73 when i can save up for them. anyone got any suggestions on good gears and/or limited slip rears?

thanks

 

What size tires will you be running? stock 265-75/16's?

I think re-gearing it to 3:73 will make a pretty big difference as far as take-off power.
12 mpg sucks for a 5.3 with 3:42's, especially with all those possible-economy mods.

My 3:73 Z71 seems do do good with my new 33's.

 

bad2006z71 - if you are only getting 12.5 mpg while granny driving, then something is wrong. Even my 93, running 33s and 3.42 with a 350 got 13.5. Try cleaning your filter and maf and see if it helps.

 

yea i just cleaned my K&N about a month ago. and running factory aluminum wheels and tires 265/70/17 duelers. its only got 21000 so im going to probably put 285/70/17 duelers when these wear out. it has been cold here 20's and so, so that might be affecting it some, i domostly city driving probably an 80-20, 75-25 mix city/highway so i was hoping for at least 14. maybe i mispoke i dont always "granny drive" i will hit it allitle but i try not to be ***** to the wall all the time. i also use 5w30 penzoil platinum and on my next change i will probably go to royal purple. in the summer with warm weather it does get a little better, usually around the 14 mark so maybe it is jus the cold weather. i will clean the mass air sensor.

thanks guys. ill post some results if i dont chicken out of the underdrive pullyes. but it will be a couple of months before i can get the cash together. http://www.aspracing.com/frame.htm

 

ok just filled my tank with about 80-85% city driving just calculated 13.6 mpg. that was getting on it a couple of times to check out the new programmer so i guess maybe when it starts getting warmer ill sneak into the 14-15 range.

 

Yeah i get about 14 or so in the city. When you go to 285 you might even think about going to 4:10 gears. Thats what me and i think a few other people are think about going with.