Upgrade for my ford 9 inch with Trac lock

[NCBeachBronco]

Hear a lot on 31 & 35 spline axles, but if he stays with his unmodified small bearing housing I don't think those are options...

 

[SteveL]

I think one of the vendors had small bearing 31st line options. Think it was wh

 

[PaveBronco]

It’s a stock block with a mild cam but it has the 90 Mustang EFI conversion and yes sometimes my right foot gets a little heavy

What size tires, gearing, and transmission?

 

[Readhead]

Stock 3 speed manual
35’s
350 gears

 

[Nothing Special]

People have told you that a TrueTrac, a Detroit (or Grizzly, same function, different brand) and an ARB are your best choice. Those are very different options, but all could be "best" depending on what you want.

TrueTrac will have very good street manners, and will work very well at finding traction as long as both tires have some traction (which is usually true when driving in snow). From what I've heard it should hold up well with your tame engine and gears.

The automatic locker will have street manners ranging somewhere between "terrible" and "good", depending on how you feel about it. A lot of us run them on the street and have no real complaints, a few people used to run them and now say that a selectable is the only real option. Neither is wrong, people just have different perspectives. It will give very positive traction all of the time, but can get you in trouble on slippery sidehills, making it very hard to go forward without also going sideways (to be fair, a TrueTrac will do this to some extent too, but probably not quite as bad as an automatic locker and an ARB will be worse when locked, and better when unlocked, if you can move forward with it unlocked).

The selectable locker will give you the best of both worlds: the traction of a spool and the street manners and stability of an open diff. It will also give you the worst of both worlds: the traction of an open diff and the street manners and lack of stability of a spool. Obviously if you throw the switch at the right times you get the good, if you don't you get the bad. Like with automatic lockers, people that have them love them and the choices they get, while people that don't have them love not having to worry about turning the locker on and off at the right times. Again, neither is wrong, just different perspectives.

So which is right for you? Only you can say.

 

[Skiddy]

Stock 3 speed manual
35’s
350 gears

besides the locker here comes the snowball affect with your wheeling conditions. upgrade
4.56 gears so much better with 35's
31 spline axles
option: big bearing
then locker of your choice and now comes the front end;D

 

[Readhead]

Well I have taken all of this in and have an open mind on all of it ..... talked to a guy in San Bernardino who owns an early bronco and sells and rebuilds ford rear ends out of necessity ... he got into the business after the 10th time he blew his 9 inch .
Told him where I usually wheel at and he knows the area since my ring and pinion are good he is going to sell me a used heavy duty track lock that is set up for 4 spiders instead of 2 and clutch packs for it . And I will just have to remember not to mash the skinny pedal on the right .... I know I should go with at least the 31 spline axels but 4 kids in collage makes it a little tight right now. Thank you all for the replies and I will let you all know how it turns out.
Chris

 

[Skiddy]

Well I have taken all of this in and have an open mind on all of it ..... talked to a guy in San Bernardino who owns an early bronco and sells and rebuilds ford rear ends out of necessity ... he got into the business after the 10th time he blew his 9 inch .
Told him where I usually wheel at and he knows the area since my ring and pinion are good he is going to sell me a used heavy duty track lock that is set up for 4 spiders instead of 2 and clutch packs for it . And I will just have to remember not to mash the skinny pedal on the right .... I know I should go with at least the 31 spline axels but 4 kids in collage makes it a little tight right now. Thank you all for the replies and I will let you all know how it turns out.
Chris

heck yeah that will work too

 

[broncnaz]

I'm with Skiddy and the others that suggest 31spline axles.. Sooner or later those 28 spline axles will be the item that is going to break. 35in tires are the key factor. I'm partial to the trac loc myself but they are limited even in 31 spline form. For the most part they just don't hold up with big tires. The next area is the clutch cover they like to blow out. Currie enterprise used to sell a billet steel one I used one on my last trac loc. and it survived my last blow up then I converted to a 4 pinion case. Hope you get a good deal on the trac loc. I can usually find one in a junk yard every now and then and it usually only costs me $80 for the whole center section. Most of the junkyard units I find are 31 spline. Funds may be tight but it shouldnt take long to come up with the extra $$ to upgrade the axles as they are not that spendy.

 

[Readhead]

What about the better. Currie axles in 28 spline then I can keep the stocks as spares for when I get stupid .... it’s not like it’s a high horse monster lol

 

[sykanr0ng]

Those 35 inch tires put a lot more leverage to twisting the axle shafts than the stock tire sizes do.

 

[Justafordguy]

talked to a guy in San Bernardino who owns an early bronco and sells and rebuilds ford rear ends out of necessity ... he got into the business after the 10th time he blew his 9 inch .

Sounds like this guy may need some 2.5T Rockwells. ;D

 

[Rustytruck]

Well I have taken all of this in and have an open mind on all of it ..... talked to a guy in San Bernardino who owns an early bronco and sells and rebuilds ford rear ends out of necessity ... he got into the business after the 10th time he blew his 9 inch .
Told him where I usually wheel at and he knows the area since my ring and pinion are good he is going to sell me a used heavy duty track lock that is set up for 4 spiders instead of 2 and clutch packs for it . And I will just have to remember not to mash the skinny pedal on the right .... I know I should go with at least the 31 spline axels but 4 kids in collage makes it a little tight right now. Thank you all for the replies and I will let you all know how it turns out.
Chris

If you really want to go this way with 4 spiders and limited slip then get the aftermarket billet steel side cover. Also if the truck wont climb it don't let it do the hopping hunting for traction, its probably why your blowing stuff up.

 

[bronkenn]

If you really want to go this way with 4 spiders and limited slip then get the aftermarket billet steel side cover. Also if the truck wont climb it don't let it do the hopping hunting for traction, its probably why your blowing stuff up.

Yes, wheel hop = broke axle

 

[broncnaz]

What about the better. Currie axles in 28 spline then I can keep the stocks as spares for when I get stupid .... it’s not like it’s a high horse monster lol

If your gonna buy axles and redo the trac loc then you may as well go with 31 spline. The currie 28 spline axles are stronger than stock but still probably weaker than stock 31spline axles. so aftermarket 31 spline should give you a decent boost in strength.
Just throwing this out there but my brother broke 2 stock 31spline axles on his f150 with 33in tires and a open diff. One of the times he was just driving normally. Of course the damage may have occurred at a earlier time and just happen to fully let go at the time it did. The point is that even 31spline axles will fail.

 

[DirtDonk]

Exactly. Add it up...
New diff doesn't cost any more for 31 spline side gears than it does for 28.
New axles don't cost any more for 31 splines than they do for 28. In fact, in some cases (at least our axles) the 31's are less expensive than the 28's!

The only thing you lose is the spare axles shafts. But what you gain by selling them to someone in good condition and the peace of mind of knowing you'll have to try a lot harder to break them is priceless.
And you could still buy another spare sometime when you feel like you can spare the budget for something new for the spare parts bin.

Paul