i have a 09 xlt on 33's I'm regearing to 4.10 and i want to put some kind of locker or LSD in the rear. and i have two questions i really need help on. 1 what is my spline count?? i really don't want to pull it apart, count, put it back together and wait for my parts to come in. from what I'm reading it is a 28 spline. but i have seen a few that says it a 31. 2) its my daily driver and i do moderate off road in it and the open diff is killing me. id love an E locker but i can't afford it. a lot of people told me to put a true trac and there not bad on cost. but i feel that a LSD is that good off road. am i wrong? iv been looking around and i found an auto locker that called a powertex no slip. it looks pretty good. its a little more than what i wanted to spend but I'm willing to do it if its that good. also its more of a locker and in my eyes thats better, but once again i may be wrong. has anyone ran any of theses in there trucks? if not any one has any better ideas. please help out at least on the spline count. i want to do this regear asap and this is holding me back.

 

Look at door tag,it's rite

 

You've got a 28 spline,
Only rangers in the 31 spline configuration were the 2002 FX4 and 2003 & newer FX4 Level II
Ford Ranger/Explorer 8.8-Inch Axle

 

Being a DD and not a trail only rig, I'd suggest the true trac. I've seen stories on jeep forums about autolockers ripping you into the next lane when they engage. They also chew up tires more than a lsd. Also, why not go for a 4.56 for those tires, its the optimal ratio and costs about the same

 

Ok thanks for the input on the true trac I may do that.at first I was looking at the 4.56 And then I started to read that 4.56 will b way to much. That I'll be doing 65 and b at 4500 rpm. Is that no true? It is a DD and I do take the highway sometimes so I don't want to completely lose highway speeds. I'm probably only on it for 5 miles at most so I'm not going that far

 

Another things is I was once told that LSD isn't really that much of help off road, is that also not true?

 

According to most of the guys on here, 4.56 is ideal for 33s. Justin (bravetitan24) was running them before he tore his truck apart for the engine swap. He would know best right now. IDK what Pedro's running. A 4.10 would be livable, but that's going to cut down on your acceleration and towing ability. I'm going 4.88 in mine here in the next month or so, but I'm going to be running 35s.

By all means a locker is going to be best off road. An auto locker should be the next best thing. However those on the road, in your DD, would not be so good. A LSD, especially the true trac will be best. I applies power to both tires regardless of the traction they have, although not equally. You can still get stuck, but much less often than with an open diff. You can get stuck with anything, in anything. For what you do, IMO you would be best off with a LSD. But its your money, and your truck.

 

ok sweet, thanks for all your help. I'm going to probably do the 4.56 and the LSD. thanks for all your help

 

Not a problem, best of luck with your build!

 

Dewey's right. 4.56 is the ideal ratio for 33's. When I had the 7.5" rear, I ran them with an open carrier. It ran just fine with a bone stock 3.0L motor for street driving. I ran the original 3.73s for awhile, and while my highway cruising RPMs were much lower (better highway MPG) the truck was so sluggish that it was no fun to drive at all. Bumping up to 4.56 made a world of difference and my combined city/highway MPG ended up being about the same as with 3.73s because I could get up to speed much easier.

Now I'll be running 4.56s with a LSD in a 8.8" rear. I'll be bumping up to 35s in the near future, but since I'm also swapping out a motor with a lot more power, I'll be keeping the 4.56s in favor of 4.88s, which is what most people with stock Ranger motors run with 35s. With the 3.slow, I needed all the help I could get to turn the bigger tires.

A quick Google search for "gear ratio chart" will show you the approximate RPMs your motor will turn with whatever combination of tire size and rear end gear ratio you want. I'd post one for you, but I'm using the mobile site so it's not quite as easy to do.

 

You can also calculate it yourself using this formula:

RPM = (MPH x Gear Ratio x 336) / Tire Diameter

If you want to know the RPM you'll be at while cruising on the highway, multiply your final answer by the transmission's overdrive ratio (I think it's 0.8 for your truck but you may want to confirm).

I made a big spreadsheet of RPMs for different speeds and tire sizes before deciding on gears to run in the 8.8 because I only wanted to regear from its stock 3.73s once. The big flaw with looking at the charts online is that you don't always know if they're accounting for being in OD or not. Hence why I made my own. When I get back home tomorrow I'll try to remember to get a screenshot of it from my iPad to post on here.

 

Thanks so much, I did look into it more, I actually found a calculator that will tell u with bigger tires what gearing you would need to get it back to what "stock" was with stock tires and it came up with 4.42 which the closet gearing is the 4.56, everybody seems to say 4.56 is where it's at. So I'm going to get that.
However now I ran into a new problem (surprise). I went to order it and the website I was going threw told me the front axle I picked wasn't in my truck... It listed 8.8 ifs which I thought was it cuz my rear is an 8.8 but it says it's only for f150
I'm reading a lot that it's a Dana 35 but from the pics I'm looking on line it looks like that's the twin Ibeam set up and mine isn't, it's just a normal ifs... So do one of u guys know b4 I order the wrong part lol.

 

Search google for "randy's ring and pinion" should be ringpinion.com
They have what's called the "diff wizard" it will show you what you have. (its most definitely not an 8.8) should be a D35 but I'm not sure since I'm 2wd

 

You are correct the front end is a dana 35 hybrid IFS diff it's different from the ttb diff in the pre 98 trucks.

If your tearing into diffs pick up a Torsen LS for the front diff while your at it. They are cheap and will truly improve your traction offroad without compromising street performance.

The trutrac is a good option for the rear

Double check your diff tag and door tag for the spline count. In 08 the lines between 28 and 31 spline axles be game to blur. It was common to see ranchos full skids and Torsen equipt 31 spline rears on sport models especially in Canada.

Also 4.56 will be excellent with 33s. ( it's what I'm running, with a Torsen front ls and auburn ected rear)

 

The only thing is the diff tag (I only checked the rear one) doesn't have spline count and from all the door tag decoder iv seen it doesn't list that either? Unless u know something I don't?

 

31 splines were only used in the FX4 Level II. As long as you aren't, you should have a 28 spline.

 

In the later years you could option the Torsen 31 spline axle On just about any 4x4

 

Post a pic of the axle tag and door sticker.

 

Thanks for the correction. I'm good with up to 05, no need for me to know much further. You gotta love the way Ford does their options.

 

sure id love to but I'm new to this site… how do u post pictures lol, i only see how to do it if its from a website

 

[ATTACH]Attachment 68462[/ATTACH]
ok i think i did it right lol. sorry for the mud didn't have a chance to clean it yet. if you can't read the diff tag let me know

 

28-spline 8.8" rear with open carrier and 3.73s

 

sweet thanks

 

No problem.

For anyone else's reference: Ranger Axle Codes

 

Where is a good place to get a Torsen for the front differential?