Underdrive Pulleys
05-20-2005, 02:18 PM
#1
Thread Starter
Join Date: May 2005
Posts: 4
Underdrive Pulleys
I have been told by a reputable mechanic that by changing the diameter of the crank pulley (which most aftermarket pulley kits do) you would be breaking the key way to the crank shaft over time and therefore be ultimately damaging the engine and voiding my warranty. Can someone please tell me if this is correct and if it is wise to change my pulleys. I have an 03 GT. Thank you for your input.
Chris
Chris
05-20-2005, 02:26 PM
#2
Retired MF Moderator
Join Date: Aug 2004
Posts: 14,891
RE: Underdrive Pulleys
putting the pullies on period will void the warranty if your dealership sees them. i know people that have been running U/Ds for years with no problems. my former teacher still has his on and he put them on not long after he got the car. he bought his 99GT brand new. he's only had tranny trouble. 
05-20-2005, 02:31 PM
#3
4th Gear Member
Join Date: Nov 2004
Location: California
Posts: 1,657
RE: Underdrive Pulleys
ORIGINAL: nanaki
putting the pullies on period will void the warranty if your dealership sees them. i know people that have been running U/Ds for years with no problems. my former teacher still has his on and he put them on not long after he got the car. he bought his 99GT brand new. he's only had tranny trouble.
putting the pullies on period will void the warranty if your dealership sees them. i know people that have been running U/Ds for years with no problems. my former teacher still has his on and he put them on not long after he got the car. he bought his 99GT brand new. he's only had tranny trouble.
I have to aggree with nanaki on this one. I had my U/P for over a year and had not any problems.
05-22-2005, 01:05 PM
#8
Super Moderator
Join Date: Jul 2003
Location:
Posts: 14,917
RE: Underdrive Pulleys
ORIGINAL: The02GT
yea dude it only makes your acc. run slower therfore giving you more power, I don't scc how it would hurt the crank unless the pullies are WAY out of balance, then mabye...
yea dude it only makes your acc. run slower therfore giving you more power, I don't scc how it would hurt the crank unless the pullies are WAY out of balance, then mabye...
05-22-2005, 03:38 PM
#9
3rd Gear Member
Join Date: Mar 2005
Location: Omaha, NE
Posts: 767
RE: Underdrive Pulleys
ORIGINAL: 99STEEDAGT
has anyone ever had problems with the idler pully after changing to UDP's? I'm on my third one in two months and i can't figure it out.
has anyone ever had problems with the idler pully after changing to UDP's? I'm on my third one in two months and i can't figure it out.
05-22-2005, 11:55 PM
#10
1st Gear Member
Join Date: Apr 2005
Location:
Posts: 111
RE: Underdrive Pulleys
yeah it really sucks.. i only have 34,000 on my 99 GT. The day i had the pullies installed there was this really nasty squeak. I thought the belt was streched or something. I bought a new belt from Ford and the same thing happened. I switched to a smaller belt. ( On my third) switched the idler pully ( also my third) and i even got a new belt tensoner. Starting to wonder if i should just put my stock pullies back on.