94 2wd manual rear axle swap

[HermanMango]

I've decided to get the best out my little ranger I'm going to need a new rear axle. It's a 4 banger and lacks power but after doing some research here I've found that my tire size and gearing doesn't line up. I just bought new tires while I was restoring the truck so I've decided to start checking my local scrap yards for a rear axle. the tires are 29 inches and thanks to some handy charts here the 4.10 gearing is what i'm after. I'd also love the get a limited slip diff as well so I'm looking for the F7 rear axle. If that's too rare I may settle for any F-series axle and redo the gears to get the 4.10. I'm just looking for input or experience people have with axle hunting. Or some glaring error I've made in my choice of axle. For those of you who frequent junk yards is the F7 reasonably common or am I looking for a needle in a junk-stack?

 

[PetroleumJunkie412]

just posted a 7.5 with 4.10s for sale today.

Otherwise, you won't regret 4 10s behind a 2.3. For the little ive driven mine, I've appreciated them.

 

[don4331]

Welcome:

Don't discount an R7 axle (8.8" L/S), while the 4 banger might not need the extra capacity, it will fit just as easily.

I'm guessing you have a 7.5" (your existing axle code, transmission, regular or super cab would be useful for us as reference). All F-series will be 8.8 (or better), so no gear swapping between them and a 7.5".

PJ, Arizona is a little ways for him to come and collect it

 

[PetroleumJunkie412]

Haha, ring and pinion is easy to ship.

Also, just put an R7 under my 1996 2.3l. Haven't run it yet, but looking forward to it.

 

[PetroleumJunkie412]

 

[scotts90ranger]

I have 29" tires (235 75 15's) on my '97 extended cab 2.3L 4x2 and 4.10's in the rear and it leaves me wanting lower... I spend too much time shifting to 4th and first lugs the engine a little bit too much sometimes... I'm going to go to an Explorer 8.8 with LS and thinking of throwing 4.30's or 4.56's and a range box... we'll see how much of that materializes, I might just go down to 28" tires... but it does need a limited slip...

 

[HermanMango]

Here is the door tag and the size of tires on it

 

[sgtsandman]

With the originally sized tires, my 1998 with the 2.5 worked well with a 4.10 rear end (same size as what your door post sticker says). Going from a 26" tire to a 29" tire is a pretty big step but looking at this chart: https://www.therangerstation.com/how-to_pages/gear_ratio_tire_size_chart.shtml

It looks like you might be ok. The Lima engines need all the help they can get, so going lower might be a better option.

If you look at the chart, the 4.10 gear threw the 1998 right at the bottom of the power towing band. So it will hurt fuel mileage. That being said, my 1998 was getting 21-22 mpg with the original 3.45 axle and was struggling to get out of its own way. Going to the 4.10 axle, there was no change in mileage and the truck was no longer struggling. Just something to keep in mind for your project.

Finding an axle with a limited slip might be tough with the 7.5. If you find one, try to go with one that has a Torsen. They use gears for operation instead of clutch plates. So no clutch plates to change when they wear out and no additive required for them to work. I don't remember when the cut off was for the smaller pinion flange being installed on the 7.5. If yours has the bigger flange, going to an 8.8 might be the better option. More axles out there and more options. There is nothing wrong with the 7.5. So if you find one with what you want in it, don't be affraid to grab it up.

 

[scotts90ranger]

Just as a note, I toyed with things attempting to weasel out a little MPG since it already had 4.10's and I'm guessing stock size tires (225 75 14, don't know because I didn't get the original drivers door) I get 23mpg with 27" tires and 23mpg with 29" tires (correcting for the 10% difference in tire size), so it didn't change anything and wasn't really worth the trouble, but the wheel wells are HUGE so the bigger tires look better and 14" tires are harder to come by anymore, and apparently 15's aren't much easier anymore since I can't find anything but snow tires for less than new price...

 

[HermanMango]

The main reason I'm thinking an F7 axel is because of the charts on [this page]. I'm hoping that since it was a factory option I'll have some better luck finding one. What other changes have to be made to put in an R series (8.8) axle If I'm able to find one? I'm still reading into which other axles are compatible. The 7.5 and 8.8 are in lots of other stuff but I'd prefer to keep this project a bolt on.

 

[Dirtman]

View attachment 47987

Yellow.

 

[racsan]

I went from 3.45’s to 4.10’s in my ‘94 2.3 and it was a much needed shot in the arm. Ive never corrected the speedometer so with 225/70 tires im around 7 mph off and its off about 5 mph with 235/75 tires. It seems to do ok with the 235/75 tires unless I try to pull the box trailer, with the 225/70’s I can pull pretty much whatever I need to. I put the stock 14’s on once to drag a dead mitsubishi across town, tons of power but you run out of rpm in the lower gears rather quickly. I went with a 7.5 as a axle replacement because thats all the local’yard had. theres was only 2 “4.10’s” to choose from, I got the one with lower milage , yes its a open diff but I can always throw a lock-rite in it later. both the 7.5 & 8.8 are 3,000 # capacity axles, biggest thing you gain with a 8.8 is bigger brakes (which also could be swapped onto a 7.5) and a better selection of rear covers, lockers & gearsets. I paid $200 for the axle I got, was still better than buying new gears & the tooling id need to set up a gearset. PJ’s $40 rear axle is a great deal, even if it is a 7.5 open. I really wouldnt go lower then 4.10’s unless I towed more or ran a bigger tire. I run the 235/75’s in summer and my winter tires are the 225/70’s. Im guessing fuel milage is in the low 20’s, some day I’ll get the right speedometer gear for one of my tire sizes so I can know for sure how its doing , but it’s acceptable as a daily driver and occasional light tow vehicle. Since Ive gotten the escape its been my 1st choice if I need to tow something, either way the box trailer is like pulling a parachute but the escape stops it better.

 

[don4331]

The main reason I'm thinking an F7 axle is because of the charts on [this page]. I'm hoping that since it was a factory option I'll have some better luck finding one. What other changes have to be made to put in an R series (8.8) axle If I'm able to find one? I'm still reading into which other axles are compatible. The 7.5 and 8.8 are in lots of other stuff but I'd prefer to keep this project a bolt on.

An 8.8, from '93+ Ranger, bolts right in. SuperCab with 3.0/Auto would be prime source for R7, FX4 would be almost guaranteed to have one. Now, the R7s probably have 10" drums and yours will have 9" (based on Regular Cab/2.3/Manual/Payload Pkg #1 off your Federal Sticker), so rear brakes will do a little more work (Might lock up in panic stop with box empty in wet). If you are really concerned about it, you can pull the axles and install your existing brakes on the 8.8 (an option if you would sooner change the differential oil rather than bleed brakes in any case - also makes axle more "portable/cheaper" from recycler if you leave axles and brakes behind).

Axles and brake mounts are identical for all Rangers from '93 to '09 with exception of the FX4 lvl 2, so swapping is option.

 

[HermanMango]

Thanks for that.

An 8.8, from '93+ Ranger, bolts right in.

The bigger my donor pool is the better my odds. When it comes to all of the other 7.5 or 8.8 axles out there are there any from other models that bolt on? I know people pull them from explorers, aerostars, and mustangs and such but I think they then have to move around the spring perches and shock mounts and such. I'm also thinking that even if I can find any LSD that works I can just order the gear set I want and put them all together.

 

[scotts90ranger]

The only bolt in axles are out of Rangers or Mazda B series of the same body style ('94 on up)