Best use of a 31-spline posi carrier?

['92Custom]

I picked up a used 8.8" limited slip carrier which I thought was out of a Ranger. Cost me $50, and looks to be in decent shape (not really sure what I'm looking at but the clutch packs are there and appear to be intact).

Anyway, I was planning to use this for a future differential build, as I'm planning to put 3.73s in and would love to have traction from both wheels. Turns out it is a 31-spline, and I'm pretty sure I have a 28-spline housing. From my reading, the 31-spline axles are incompatible with the 28-spline housing.

So the carrier is a sunk cost, what's my best path from here? I'm leaning toward rebuilding the diff regardless so I can start with new pinion and carrier bearings, get a lower ratio, and so I can learn how to set up gears...

Does anyone make 31-spline axles that fit in a 28-spline housing? I don't mind paying for upgraded axle shafts since the carrier was so cheap. Or would it cost less and be easier to swap in a complete Explorer axle?

 

[94 lngbd]

unsure of the years but its listed in the rear end info if you do a search. FX4 level II Rangers used a 31 spline axle but it was a stnd 8.8 ,NOT the stronger explorer 8.8 housing. So If your able to locate those from a bone yard then do it other wise there are several after market companies that make 8.8 31 spline axles that are stronger then stock.

 

[brinker88]

Sell it is your best bet and try to recoup your money.

 

['92Custom]

Okay, I threw it up on Craigslist, I'll see how that goes. Live and learn. In the meantime I'll look into custom axles in case it doesn't sell, but that may be cost prohibitive.

 

[Mac]

unsure of the years but its listed in the rear end info if you do a search. FX4 level II Rangers used a 31 spline axle but it was a stnd 8.8 ,NOT the stronger explorer 8.8 housing. So If your able to locate those from a bone yard then do it other wise there are several after market companies that make 8.8 31 spline axles that are stronger then stock.

I'd check where you got these facts. Same 31 spline axles as the Explorer and same dia of axle housing, same bearings. What would make the FX4 weaker?
Dave

 

['92Custom]

Okay, looked at this thing a little more and I'm wondering, is it possible to change it into a 28 spline by swapping out the side gears?

 

[alwaysFlOoReD]

This is what I've wondered too. I don't have any to compare.

Richard

 

[85_Ranger4x4]

I'd check where you got these facts. Same 31 spline axles as the Explorer and same dia of axle housing, same bearings. What would make the FX4 weaker?
Dave

IIRC the shafts are different lengths, otherwise they are the same though.

Aside from the wheel bolt pattern they are the same as the stupid common 8.8 that has been in fullsize trucks and vans since the early 80's.

 

['92Custom]

I contacted a guy who rebuilds these, he said the 31 spline and 28 spline side gears are not interchangeable. He did offer that if I shipped him my 31 spline carrier as a core he would send me a rebuilt 28 spline from his inventory for $80 shipped. I may go for this if my carrier doesn't sell locally soon, I'd have a rebuilt posi for about $130 (plus shipping to get him my 31-spline unit) which seems reasonable.

 

[brinker88]

^ That would be your best bet.

 

[4.0B2]

yeah, rebuilt posi for that ain't bad... i'd send him that one and get a rebuilt one from him...

 

['92Custom]

Do you think it will make a significant difference in my 2wd street/occasional off-road truck as far as the fun factor goes? I'm thinking that plus the 3.73 gears and this truck will be a blast to drive, as if it weren't already...

 

[4.0B2]

what gears do you have now?
LSD will help, no doubt... but an Aussie is better! lol.

 

['92Custom]

3.08s.

 

[4.0B2]

3.08s.

oh yeah... you'll love 3.73's