im doing a gear swap from 3.55 to 4.56 wednesday and a buddy ofmine said since i do alot of long distance/highway driving the gears will over heat and seize up. if this is true what can i do to make it not over heat?

 

Just out of curiosity, why are you going to 4.56 gears? If you long distance/highway driving, you're going to absolutely kill your gas mileage.

 

I think that we as a forum and members need more information about your truck, (Year, model, motor size, tire size, 2WD or 4WD) before any good help can be provided. In my opinion, if you are changing tire size and going with a larger diameter, then maybe 4.56's are a good choice. There are alot of variables.

 

You need to follow the break-in procedure EXACTLY, then you should be fine. In other words, no long distance/highway driving for the first 500 miles.

 

2003 ext cab 4x4 4.6l 6"lift on 35s. and it gets about 10mpg now so im really not that worried about mpg

 

Archangel, glc is correct with the breakin procedure. I have attached a link to Randy's Ring and Pinion. This site seems to be pretty reputable, and they have very good info. Also in my opinion your gears with that tire size should be fine, you should regain a lot of your low end, and gain some better fuel mileage with in town driving. Do you by chance have a programmer on the truck?

http://www.ringpinion.com/FAQ.aspx#37

 

no programmer yet, i was thinking about getting one when i swap out motors in the next few months, i appreciate the help

 

I have 4.56's in my truck and I have pretty much stock sized tires. My RPM's sit at around 2800 cruising 70-75 on the freeway. I have driven multiple 2+ hour drives and haven't had any sort of overheating problems at all. My transmission temps run a little higher than with the 3.55's but they aren't high enough to worry about. The Altamont Pass is a breeze now, my truck doesn't hunt for gears and didn't downshift once going over it.


I followed the procedure that was linked in a previous post and on glc's recommendation I waited until after the 500 mile fluid change to put my performance tune back in it. I have about 1,200 miles on the new gears now and am very satisfied with my choice of going with a 4.56 ratio.