So guys, tell me the difference between th 28spline 8.8 axle and the 31spline 8.8 axle. I'm a lowered street truck, so I'd really like to stay away from the wider 31spline 8.8 axle. But please tell me teh advantage to the 31spline axle. Being mostly street, I'd assume a L/S is really all I'd need and I know i can get those for the 28sspline easily. If i ever do an engine swap, i know a 28spline axle can handle more than 300rwHP so i'm fine there.

Really, i just want to know when i swap axles I'll be doing it only once.

 

The only difference there is between the two is the strength. You really don't need a 31 spline unless you put in a huge V8 with like 400+ HP. The 28 can handle fine, but imo i would put in the bigger of the two, just in case. S**t happens, so you might as well go big or go home.


Here is some good carnage of a 28 spline!

 

i would LOVE to see a 28 spline 8.8 take that much power.. maybe 400hp if you play around once in a great while, but i wouldn't trust it for someone who drives like me.


a 31 spline has bigger diameter shafts, as well as the more splines you have, the shallower the 'spline' there for leaving more material on the shaft for strength.

both are C-clip obviously and i just have a thing against c-clip axles.. soooo you should get a 9"

full float
40 spline
nascar that **** up!! bwahaha

 

Alright guys, i've determined that I can either

1. Be Explorer: stronger axles, but wider (possible problem being lowered) and have to weld on shock mounts (nbd, i can weld).

2. Be Ranger: stock width, but be weaker. Easier swap.

I want to get limited slip, and can probably get it stock with 3.73 gears in an expo. but would probably have to pay for it in a ranger.

Dam these catch 22s or whatever on upgrading my rearend.

 

Grant, go expo. Spring under with relocated shock tabs and disc brakes with 3.73's and a LS.

Best bang for the buck.

 

Well, im giong to do cobra rear brakes in the back so it won't matter which axle i go with, only spline count and width is my concern.

 

Do you really think your going to need that extra strength with the 4 cyl? If you swapping disc anyway I would just go with whatever one you can get cheaper.

 

duh i don't need teh strength with 2.5l of fury. I want to be set with the rear end indefinitely. when i do an engine swap, i want the strength already there. im thinking which ever one i can get with limited in it already i'll go with. Will be hitting up the junkyard for sometime...

 

I'd stick with the 28 if your mildly concerned with width. Despite what some here think, a 28 spline will take a beating on the street, even with sticky meats. Keep the lower track width and just upgrade to a stiffened up OEM Trac-Loc or aftermarket unit and then the brakes. I'm not sure on the size of the weight difference but a 31-spline will weigh more than a 28.

That's just my $0.02, and what I'm most likely doing to clear 285s and Cobra rears..

 

Yeah, i think i am going to stick with the ranger 8.8. Shane has one already with 3.73 gears i just need to add a limited slip and probably change out the bearings and seals while i'm in there. Where do you go to get a stiffened up trac-loc (is trac-loc same as limited slip?)

 

Shane has a trac-loc waiting in the shop too!

 

o rly? I thought it was for a 31spline or something?

idk, it might show up missing here one of these days...

 

Nope the Torsen he has is for our 31 spline... The Trac-Loc is for a 28 spline. Austy was thinking about buying it for his truck. Better beat him to it lol

 

Grant>Austy. so no worries. Is it new? think i should rebuild it? what exactly is a track loc anywyays? i don't get it.

 

I just bought an expo rear. With the mustang offset wheels, I'll have no problem fitting the extra width, and the width will actually let me get rid of the wheel spacers. Plus, for 200 bucks, already equipped with LSD, rear sway bar and disks, best bang for your buck. Also, I've heard that if you get 2 driver side spring plates from the expo, you won't need to weld on shock mounts. I'll let you know how that works out when I get mine in.

 

Just a rebuild kit, add a few extra clutch pack discs, F150 S-clip and reduce the amount of Limited Slip Additive you add to the fluid will make it lock up nice. I had a site with detail on all the options I'll dig up later tonight.

If you're running 8/9" NON-deep dish, I don't think you will have a tire-to-fender problem with the Expo axle. If you're running a less offset wheel (deep dish, 10-11"+), the OEM axle puts you just barely within the fender, a 3/4" wider on each side addition would cause some serious fender clearance unless you rolled your fenders.

I got a link on that too later tonight.

 

damn if you were closer i could get you an exploder axle with 3.73s and ls and breaks for around 100 and around 50 with out the breaks

 

custom 9" never be concerned again.

 

Fixed it for ya.


OP:
Nice thing about the explorer axel, is that it is already spring under. That will equate into less axel hop, and already net a 5 inch drop in the rear. If you can IMO I would.

 

the torsen diff is a gear based limited slip.

the trac-lok is a clutch based limited slip. ford offers a carbon fibre clutch kit for the 8.8 that is factory equipment in the higher end solid axle mustangs.

 

I never got why they did that. Why not just throw a locker in?

 

spooled 35 spline FF 9"
dont question it.

 

The width is only 3/4" on each side. Will that really make that much difference for you? Plus you get the drop, strength, discs, and LS. I'm not seeing a down side for you yet...

All you'd need is new u-bolts, a brake line, and some work. (Depending on condition of axle and what you get with it)

 

I'll measure when i go home next...just eye balling it my wheels are pretty close to teh fender lip for my liking.

I can get complete axles at the junkyard for 100 any day. There are a few guys parting out explorers on CL, but most of them think they're sitting on a pot of gold and want lots of money, but we'll see what i do there.

Oh, i already have the flip kit for my truck installed so its no worries there. I guess i could sell that part if i go with the expo to recoup some money....

 

The 28 spline will be plenty fine for you.
But there is nothing wrong with the Explorer axle either. The discs are nice to have in the back, not for better braking, but they are just easier to deal with, and you don't have to worry about the rear brakes locking up with moisture. The extra width is probably not an issue, it's only 3/4" each side. And it's only .3" or so wider than the front track width iirc.