I've been interested in getting the under drive pulleys from under dog performance and now that they have the kit for the 4.0 and its on sale i was going to get it
i think that the hardest part is going to be getting the crankshaft pulley off since i did the fan clutch a couple of months ago. is there any helpful hints to getting it off.
and/ or does any one have a set that they are willing to sell?
thanks
and this is going on a 97

 

if you use an impact wrench, the crank pulley nut will spin right off......I have it on my '97 and love it...you will need the alternator pulley also to get your alternator back to normal..

BTW: you have 2 post on this.....

 

An impact will fit down there? Guess I never really looked.

 

you have to take the radiator loose and have someone pull it up....then it will....

if you don't use an impact, you will never (safely) get the pulley off....

 

You can hold the motor still with a metal strap bolted onto the flywheel.

Rich

 

make sure you torque that new pulley down to spec. If you have an automatic you need to clamp things down like Rich stated. If you can't keep the motor from turning, you won't be able to torque it down. Don't take chances on this part of it.

 

well i was going to get the kit that has everything except for the idler since i just replaced it.
its $360.00 with 3 pulleys and a gator belt so its not too bad
any one know the actual millage increase with these on?
http://www.stuffforyourranger.com/st...90da0a31842295

 

you wont really see any milage increase.......it really takes more than just the pullies to get a noticable milage increase...

 

You will notice a decent increase in power. And to some extent it does help mileage as well. It just takes a combination of things to get that fuel consumption down.

IMO the underdrive pullies on a 4.0L is one of the best bang for your buck mods you can do.

Rich

 

The weather changed very soon after I installed mine on the 4.0. The best way i can describe the mileage improvement in the short time that I had similar weather conditions-

you know how one time you get 18.3 mpg and the next time you get 19.5 mpg? The low/high range that a truck usually stays at? The 19.5 became the lowest mpg, with the occasional fill up that netted better.

I guess I would say a solid 1mpg.

 

I think I need to add these to my list. LOL

 

Skyway! if you plan on doing the mod....can we get a "how-to" post made of it. Im interested to see the whole process in pictures and not just a list of instructions.

 

http://stuffforyourranger.com/How_To...nderdrive.html

above is a brief how-to. each step has its own issues so don't take it that it is extremely easy. locking the engine down lessons the headaches substantially.

 

make up your mind....either work on the 4.0 or put in a v8 geeze

 

This is not exactly a how-to page. But it's some usefull info I put together.

My web page

 

thats reminds me does anyone have hard data of the under drive pulleys vs. stock?
the "harmonic balancer removal tool" is that just a steering wheel puller?
and are they made of steel of aluminum'?