alright i have the 4.0 crank UDP installed presently.....i bumped the RPM's of my truck up with the X2 that I have, but when the A/C is on and the 130A alternator (which is brand new - roughly 2 days old) slows down enough to draw the voltage down to about 12.5v at idle......

so I am thinking I need to install the smaller alternator pulley that Wayne sells......anyone have any opinions on this

also, what about the water pump pulley it says in the description the following:
is that true? will it help cool the engine better (not that i have a problem now, but any small bit will help!)

 

bumbage

 

it will turn both the water pump and alternator back to original speed.

i say you need both.

 

that is what i thought, but i remember someone saying that the water pump pulley would turn it slower.....

 

i think its a smaller pulley not sure tho

 

the way i read the description it is.....
http://www.stuffforyourranger.com/st...fe460d85eb09d6

it says it is an underdrive pulley...

 

the water pump pully is the same size as stock
so it will not change a thing,it is lighter though.
i have the whole set but water pump pully is still on the(I NEED TO BE INSTALED ON THE RANGER)shelf lol one day ill clean it off
so you dont need it but it was a nice packaged deal so i picked up the set

 

you got the 3.0 though.......the 4.0 and 3.0 water pump pullies are different...

3.0:
http://www.stuffforyourranger.com/st...roducts_id=164

4.0:
http://www.stuffforyourranger.com/st...products_id=41

 

all the post i have read asking the same question gets the same answer
3.0 or 4.0 there the same size as the stock ones
so to answer your post question no you dont need to purchase one just the correct size belt

 

read the discription....the 4.0 pulley says nothing at all about being stock size.....it says it is a 20% underdrive pulley....that means it is smaller than stock.....

4.0 Pulley Discription:
3.0 Pulley Discription:

 

I've been running a crank underdrive (only) for about 10k miles.

So far I've settled on 704 rpm idle. It seems to suit everything just fine. I know you have lights and stuff.. and I'm stock.

But I have data logged and with EVERYTHING running at max I drop to 11.4V at that rpm.

Also, about a month ago I was sitting still in 90F temps for about 1.25 hrs. Had the AC cranked, e-fan running 100%, and radio on. Took it about 35-40 minutes for the temp to start creeping up. Then at about the 50 minute mark I had to shut the motor off because my temp guage was nearing the top of the normal range.

But in reality.. that'll just about be the only time in this trucks life that I'd sit for that long and the AC cranked.

btw, a 85" belt is a little too long. And a 84" belt is too short. An 84.5" belt is perfect for a crank only pulley.

Rich

 

the problem i am having is when i go to take back off from the low voltage drop is that my A/C compressor pulley squeals like a stuck hog......and wont stop until i stop the A/C and get my rpm's back up and then i can turn the A/C on.........

any idea's Rich?

 

ilde to low?

up the idle a little

 

I have a 85" gatorback belt. (only thing the local store had)

The *only* time it squaks is when it's been sitting overnight on a humid night.. or in really cold temps. And even at that it only gives out a little squak as the motor is starting.

At the same time.. my truck is pretty much new too. One with more wear on it would have a bit weaker tensioner spring and front end components that would be a bit harder to turn. I'd think anyway..

Rich

 

just for clarity.

underdrive means it spins less revolutions.

in the case of an underdrive crank pulley it will be a smaller pulley so that each revolution of the engine will turn the components less.

in the case of an underdrive water pump pulley it will be a larger pulley so that the amount of belt passing over the pulley will create less revolutions.

also the 3.0 water pump pulley that wayne currently sells is the same size as stock. however, he used to sell underdrive water pump pulleys which is what i have.

 

i have a new tensioner pulley and A/C clutch & pulley......i will go see if O'Reilly Auto Parts has a 84.5" belt tonight too see if that works.....hopefully it does.....maybe i have a 85" belt i got from Wayne......

it says on his site that the 4.0 with a UDP only should have a 2" shorter than stock belt........maybe i got a 1.5" shorter than stock belt....i can't remember what length i got....

 

what does the smaller crank pullie do any how???

 

Gives you a couple extra horsepower, allows the engine to run better.