Axle Replace

[JerrySab]

Hey friends!

I'm looking for the most cost effective way to change my gearing from 3.45 to 4.1. I'm not quite up to the task of replacing the gear and pinions in the rear diff. I do, however, feel like swapping a complete rear axle with the desired gearing would be achievable. I currently have 7.5", on '88 XLT 2WD extended cab.

THAT SAID,

- Am I totally wrong, and shouldn't be intimidated by the rear diff can o worms? I'm really intimidated by that thing and really don't want to be all up in it's guts.
- Is there a stout rear axle from another model and year (explorer perhaps) that pairs well with 1st gen frame/leaf mounts?

Thanks everybody!

 

[JerrySab]

Aaaaand this is the wrong forum. Posting in axle forum BRB.

 

[RonD]

Welcome to TRS

Changing the whole rear axle is what most people do

1983 thru 1992 Rangers used 7.5" or 8.8" rear axles, you can use either, same drive shaft hook up and wheel pattern

1993-2011 had 2" wider axles, and you can use them, it's just the rear wheels will each be 1" farther out, but the frame was the same to bolt it up so interchangeable in that respect

When changing axles its best to pay a bit more for a Limited Slip(L/S), this means BOTH rear wheels get power instead of just one, like a regular(OPEN) axle does, but up to you

car-part.com is a good place to look for used parts in your area(zipcode)

most 7.5" had 9" rear brakes, 8.8" can have 9" or 10", this matters when getting new brakes for the new axle


Swapping gear ratio requires some tools and knowledge, to set up pinion shims and axle shims, anyone CAN do it, just need to "measure twice and tighten once" lol
You can learn to do it, but if you won't be swapping ratios often then just buy the whole axle

 

[PetroleumJunkie412]

Whole axle method is my preferred.

Look for one with a limited slip. You won't regret it.

 

[rusty ol ranger]

8 nuts, a driveshaft, brake line, and parking brake cable the rear end is out. Much eaiser then swapping gears in the carrier

 

[scotts90ranger]

Yeah, changing the whole axle is easiest, but there's a caveat on first gens...

In '89 they changed to a bigger flange on the axle end and possibly a bigger U joint...

 

[PetroleumJunkie412]

Yeah, changing the whole axle is easiest, but there's a caveat on first gens...

In '89 they changed to a bigger flange on the axle end and possibly a bigger U joint...

YOURE A FLANGE

 

[SenorNoob]

About that flange, I changed my 7.5 from the small flange to the large one when I swapped driveshafts. I was careful to get the pinion nut back where it was, but it didn't save the axle. Moving that nut caused gear mesh problems which led to oil looking more like anti-seize a couple years.

Edit: I did it knowing I'd be swapping in an 8.8 later.

 

[JerrySab]

So is the next most straightforward path would be to upgrade to 2nd gen driveshaft when swapping axles?

 

[Shran]

YOURE A FLANGE

Your face is a flange.

About that flange, I changed my 7.5 from the small flange to the large one when I swapped driveshafts. I was careful to get the pinion nut back where it was, but it didn't save the axle. Moving that nut caused gear mesh problems which led to oil looking more like anti-seize a couple years.

Edit: I did it knowing I'd be swapping in an 8.8 later.

There were probably some tolerances out of whack when you did that! Just getting the nut back to where it should be is irrelevant in this case... the new flange could have been slightly longer or shorter and that would mess with your bearing preload, shim pack, etc

So is the next most straightforward path would be to upgrade to 2nd gen driveshaft when swapping axles?

Your easy button would be an 89 or older axle. Second option would be drill and tap the flange on the newer axle to match your driveshaft bolt pattern. You could also use a 2nd gen driveshaft.

 

[rusty ol ranger]

So is the next most straightforward path would be to upgrade to 2nd gen driveshaft when swapping axles?

Or just find a 1st gen axle

 

[PetroleumJunkie412]

Your face is a flange.

Well, I can't argue with that.

 

[JerrySab]

Or just find a 1st gen axle

I’m kinda good to ditch the center bearing nonsense.

 

[scotts90ranger]

Assuming you have a A4LD as it should you can use a '98 rear driveshaft apparently to get rid of the carrier bearing, then an '89-92 axle would be perfect... if you don't mind a 1" total width increase that opens up a bunch more years...

 

[gaz]

JerrySab,

The pinion preload is only an issue when disassembling and reusing same ring/pinion. I accidentally used my big torque wrench while performing my 1st tear down and out of habit glance at the measurement...total fluke. So I used that value during reassemble, worked perfectly!

My 1st re-gear was an axle swap. For me, it would have been cheaper to buy new gears; being my daily driver, needing complete reliability, I completely rebuilt the axle reusing only the near perfect condition factory ring/pinion, axles and hardware. All bearings seals and consumables we're replaced. This axle was older with unknown miles but in good condition, brought back to full service health.

2nd re-gear was another axle swap. This time I didn't get the ratio I wanted so I inspected, cleaned and replacing the fluid and brakes only. This axle was much newer with very low miles and I knew that I would be swapping ratios in the near future and performing a complete rebuild with that.

Both axle swaps involved changing from 9" drums to 10" drums. This caused no issues other than my brakes felt better for both vehicles .)