I just noticed yesterday while I was under my truck that the passenger side rear axle seal is seeping. I plan to change both bearings and seals at the same time in the future. I plan to run 33 inch tires in the next year and a half, should I look at beefing anything up in there? Should I regear being how I do tow quite a bit. I have the 9.75" rear with 3.55 gears and limited slip.

 

Keep in mind this is my daily driver 14 miles combined everyday to work and back and when I do tow im only running 65 for a short period of time, 20-40 miles usually. Majority of the time I run on the interstate towing at 75. I don't want it to be screaming on the interstate or highway running empty, but I also don't want to be short on gear for pulling my enclosed car trailer with a 3600 pound car inside. Even pulling my dads new 2012 skeeter MX1825 boat up to the lake and back it was working its but off pulling the hills (18miles one way to the lake) and Im not even sure on the weight of the boat. I've never really messed with gear ratios, so I am trying to read and learn. Just a little FYI guys. Thanks

 

If you can afford to re-gear, and don't mind a mild highway gas mileage loss ) un-loaded, probably won't descend/ascend after either ), of coarse, re-gear. 4.56 and you will pull very well, and can handle 35s in the distant future.

 

I guess the other thing I was thinking is just to get in there and replace the axle seals and bearings for now and then wait til I get some other mods done first and address the gears when I do wheels and tires in about a year.

 

What kind of R's would I be turning at 65mph and 75mph with 33's and 4.56s?

 

http://www.grimmjeeper.com/gears.html

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How many RPM are too many for a 5.4 running a consistent 75mph highway speed for say....500 miles running empty? Would 4.10's be a little more friendly then 4.56's with 33" tires? or can I run my 01 Screw with 35's with the truck just leveled?

 

I would like to keep myself right in the powerband, I use to have a powerband sheet for the 01-03 5.4 2valve, but can't find it anywhere. 5days per week I drive to and from work 65mph and 14miles total everyday(45%). Every weekend I usually pull a 18foot boat or car trailer(25-30%). The other 30% I run empty to Bismarck(80miles each way), to do shopping or hit the lowes for supplies(65 for 28miles and 75 for 52miles), sometimes empty and sometimes loaded with a trailer. I plan to run a true 33inch tire or as close as I can get to one. What is the ideal rpm I should be running on the highway at 65mph and 75mph? I'm leaning towards the 4.56's just for pure performance and I think they would work great for hunting in the snow and mud but, I need a little bit of insight first on how the 5.4 and 4R70W will handle and react to them. Back before there were overdrives V8's would turn around 3,000Rpm at 70 no problem. Idk, just need some of your guys' opinions I guess. Thanks

 

How are Platinum Torque Gears? Anybody heard of them? I found them on accuautoparts.com $188.87 for the rear and $156.18 for the front and that is 4.56's.

 

Yep, and that was also in the days of low-revving pushrod engines. OHC's will wind up like a cheap watch in comparison. The redline on a 5.4 is in the 6000 rpm range, but 5400 is the practical limit due to possibility of stock torque converter ballooning.

 

Your darn right they will! Haha. I'm thinking 4.56's they just sound fun for the majority of my around town and back and forth to work commute not too mention it should pull like a raped ape....for a 1/2ton. First I need to do headers, then get a tuner for it, then do wheels/tires/gears.

 

just an fyi, on rpm, for every 100 rpm change it is worth up to .8 mpg at hwy speeds....the oem has that engine really designed to run as low as 1400 rpm for mpg, but anything below 2500 rpm and the engine should be happy, above that for longer durations will take a toll over time

 

I re-geared my 2000 Expedition when I noticed my axle seals were leaking. I picked up some master install kits and it took care of all the leaks I had. I went with 4.10's and I think they are ok (brought it back to stock acceleration), but I don't drive my Expedition much and think 4.56's would have been more fun. I didn't get the Expedition for gas mileage, so I won't really complain about the 11.7 MPG I've been averaging over the 4.25 years I've owned it.

Also, if you are planning on re-gearing your truck, that would be the same time you'd want to install a limited slip or locker in the rear if you don't have one.

 

Yeah, I average a best of 13mpg back and forth to work and around town, 8-11mpg towing, and a best of 21mpg on the highway with the wind pushing me empty. I'm not worried about mpg's because alot of my driving is towing or back and forth to work. I have factory limited slip and when it is apart I am going to inspect the clutches and I will rebuild it if the clutches look pretty worn. I will have close to 100,000 miles on it by time I pull it apart, should I just put new clutches in the limited slip right away while I am regearing it? With a true 33inch tire, I am thinking that the 4.56's are going to be the cats meow for what I do with my truck.

 

Also, what are the part #'s for the axle seals and bearings that I need? Thanks