OK, non mechanical noob needs some more help. If I word this wrong please correct me as I am trying to learn.

I have toyed with the idea of changing my 3:73's to something taller as I spend about 80% of my time on the interstate. I currently have a 7.5" open rear end with the 3:73 gears. It looks as if I have two options to stay with the 7.5". These are an open rear end with 3:45 gears and a limited slip (L/S) with the same 3:45's.

What is the difference between the open and L/S?

Also, I see there is a 3:55 but not in the 7.5" only the 8.8". I assume swapping to these would throw off the speedometer And I'm not sure I would like that. Maybe any swap would change the speedometer, I don't know. I just thought that staying with the same 7.5" would keep the speedometer the same.

I think the 3:45's would probably be a dog for in-town driving but I might be willing to give in on that matter if the highway benefits were enough to offset the loses.

It's not like I'm going to run right out and do this, but it's is an idea that I would like to go over in my head for awhile, but the mechanics of it all are confusing to me. Any insight on this one is greatly appreciated. Thanks

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Little Black Ranger: R.I.P Born-1997 Died-2018. 297k miles of good times. You will be missed.

Oh Deer: 2003 XL 2.3L 5-speed stick w/OD. Current mods: Body work after hitting a deer 12 hours after I bought it. Averaging 32 MPG on the highway.

open means the right rear tire spins only

l/s is both spin at low traction or under 20mph then acts like an open

If it is open the the inside tire seems to spin because it has less weight on it and it breaks lose. Most on road vehicles have open diffs i'd say. But i would have L/S if i could

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2004 XLT ext cab 4.0
Add a leafs in rear and torsion keys in front
265/75/16 cooper discoverer AT3's
flowmaster super 44, 1 inlet 2 outlet.. cats gutted
pioneer head unit, hifonics amp, 2 kicker cvr 12"

Limited Slip !!!

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2001 Ranger Edge 4x4 (sold)
2006 F150 Lariat 4x4 (sold)
2007 Explorer XLT (Destroyed by Deer on highway)
2014 Explorer XLT (inherited from parents)

WRONG! open means that which ever tire has less traction spins.

limited slips (ford ones) use clutches to help spin both tires in low traction situations.

and no matter what, changing your gearing from 3.73 to something like 3.45 will change your speedometer. the 7.5 only refers to the size of the ring gear, the ratio changes speed, acceleration, etc.

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Why does everyone think prerunners just jump stuff?

Please click HERE to watch this video!

yea, your correct

So this is wrong.

An open diff the side with less traction will spin. A limited slip, limits the slip dependant on the model a portion of the torque is sent to both wheels. They can also still act like a limited slip at speed look at every single sports car at speed especially mustangs running the exact same traklok LSD.

As for doyouquaxu the FX4 level 2's do have a Torsen LS which is gear based (like a detroit) unlike the clutch based Traklok like he mentioned. The ones in the Ranger specifically have the cheap clutches unlike the carbon ones in the cobra's

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'05 Ranger Edge SAS'd, 5.38's, D60/D60U, 38.5" TSL SX's, October 2012 TOTM, build thead

this

just a side note. the reason the right rear spins when you drop the hammer in an open diff is because the direction of rotation of the driveshaft......jsut a little useless info for ya. LOL

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99 4x4 w/ 4.0l and 5 speed (daily driver), 89 Mustang LX 5.0 (play-toy/expirement in progress LOL), 03 Focus ZX3 (wife's car)

i always figured it was because there was less weight on that side (gas tank and driver on driver's side of truck). good to know

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Why does everyone think prerunners just jump stuff?

Please click HERE to watch this video!

Thank you all for the information. Like I said I am no mechanic, but I love to tinker with my truck. I think I understand about the 7.5 and 8.8 thing. It's is the size of the "guts" in there, right? The 3:73 or 3:45 is the ratio of the gear sets(?) to each other? And after reading these replies I think L/S is the way to go if both sides spin at low traction/speed. If only the right side spins with an open type and that is the side that has low traction (snow or mud) what good is that?

Is there any general rule of thumb on how far off the speedometer will be? Is it something that can be recalibrated and how much of a PITA might it be?

Thanks again for helping out this noob.

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Little Black Ranger: R.I.P Born-1997 Died-2018. 297k miles of good times. You will be missed.

Oh Deer: 2003 XL 2.3L 5-speed stick w/OD. Current mods: Body work after hitting a deer 12 hours after I bought it. Averaging 32 MPG on the highway.

As far as what good is the open diff question; its not I believe they only use it because its cheaper.. but idk bout the rule of thumb for speedo adjustmen but I do know you can have it recalibrated. Call some shops to see how/where to get it done..

sent from my android via tapatalk

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-Rob

1998 Ford Ranger: 3.0 V6 -- 5-Speed -- 4x4 -- Single Cab -- XLT -- Black -- Check out the build thread for mods..

XBLGT: ob269

I think this might be a viable option for me. I know that some of the Rangers came with this rear axle but I think they came on other vehicles also. I'm sure there are Explorers with them and maybe even Thunderbirds or Mustangs. Does anyone know of a list anywhere having rear axles and what different vehicles they may have come in. Walking around the pick n pull checking every Ford door sticker and diff. tag is not my idea of a productive day.

Rangers, Explorers, Mustangs, T-Birds, anything else for sure?

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Little Black Ranger: R.I.P Born-1997 Died-2018. 297k miles of good times. You will be missed.

Oh Deer: 2003 XL 2.3L 5-speed stick w/OD. Current mods: Body work after hitting a deer 12 hours after I bought it. Averaging 32 MPG on the highway.

Explorer requires welding of shock mounts to the ranger location on the rear axle if you wanted to do an explorer swap.

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2000 Ford Ranger XL 2.5L 5-speed RWD 3.73 open - 170,000+ miles
Buggman LED 3BL/CARGO, Buggman Stang Dome LED conversion, LED Brake Light conversion, Line-X O.T.R., Air silencer removed
2.3L Headgasket/TIMING/Water Pump replacement guide

I assumed sticking with a Ranger axle would be the best. Finding one I think will be a killer though.

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Little Black Ranger: R.I.P Born-1997 Died-2018. 297k miles of good times. You will be missed.

Oh Deer: 2003 XL 2.3L 5-speed stick w/OD. Current mods: Body work after hitting a deer 12 hours after I bought it. Averaging 32 MPG on the highway.