Moser has a dedicated full float axle for autox but by the the time I’m done building it out I’ve got brakes I don’t want and different rear studs from my front studs and I’m in over $2600 without even building my 3rd member. No thanks. So I’ve looked at the standard 9” with semi floater and built it out WITH a light weight nodular 3rd member for the same price complete but it is a semi floating axle flanged to the axle tubes with pressed on bearings. Flanged, do these 9” Ford axles handle the abuse of autox and HPDE with sticky street tires? Sticky like ultra performance summer tires so in the scheme of things not really all that sticky. Do they suffer the same drawbacks as c-clip axles such as pad kickback and destroying the axle seals? I’d think not but still gonna ask. Thanks for the help y’all.

 

Do you need a 9" for autox simple answer is no. Any rear you go with isnt going to make a difference with your lap times also what kinda hp you making?
Autox dont really put a hard load on the rear dont matter if your running super sticky 200tw tires or not. If your under 400whp a well built 7.5 is fine other then that I would buy a 8.8 housing from hawks and build it how you want.

 

It’s a street car first and foremost and I’m not hunting for time on any autox course. The why is that I need to beef up my rear end because of the 383 and T56 I’m running is munching up my stock 10 bolt. Pinion has play in it and the seal is leaking after just a couple thousand miles. Talked to moser today about why they say the tapered bearing housing ends won’t play with LT1 rear brakes, didn’t get a real clear answer but they said their bearing supplier for the tapered bearings has dried up with no ETA on a resupply. So still hunting as information regarding axle design for anything but drag racing is dang near impossible to find online. As to your suggestions with the 8.8” and 12 bolt what I don’t like about them is they’re both c-clip axles like the 10 bolt meaning lateral play on the axle is solely handled by the c-clip into the diff bearings which is pretty substantial force imparted through a very insubstantial part.

 

You can have an 8.8 and 12 bolt with Ford ends

 

I think your over thinking the c-clips cause I haven't seen one fail yet on the track but its your car. Like 84 said you can eliminate them.

 

I KNOW I’m overthinking it because I really don’t have a lot of experience to fall back on. So, I’m asking and listening to experienced voices as I’m not anxious to drop $3k. I’m just voicing my concerns as I like to watch other people makes mistakes and learn from that vs making those mistakes myself. It you REALLY think a 10 bolt can appreciably survive the abuse then I’ll shoot for it. But everyone says of building up 10 bolts what they say about building up a 305 and my current one is following that trend. I can drop 40% of the cash now of an aftermarket rear to build what I’ve got now and likely 100% later or just drop the 100% now. Btw way emailed Bruce at Hawks about their 8.8” and they’ve eliminated the c-clips from their builds. That’s the route I’m going if I go that road.
You asked earlier about my setup. 4-bolt roller SBC, AFR 195 heads, low 9.8:1 compression, Jones camshaft 232/236 .576/.576 , partially ported Vic Jr, Holley Sniper EFI and Hyperspark, Dyno Don’s headers, my homemade 3.5” exhaust and LT1 T56. I can’t imagine any 10 bolt I put together would have a long life ahead of it as this one proved and that’s just after a few street hits. I don’t know what power it makes but it has potential.

 

C clips also let the axles move in/out of the housing and can cause pad knockback, which is the last thing you want while racing and going around turns

 

First time I did autocross my car was about 5 years old and it blew both rear axle seals in the 10 bolt and the oil ruined both rear brakes. Bad luck?

 

Maybe its just me but I all most never touch the brakes on the track but if i was building a all out track car then I would be more worried about it im sure.

QwkTrip between you and me we have enough bad luck for everyone lol.

 

Ha! That's for sure. My axle is out of the car right now because I did something dumb... again

 

You can build a full floater from a circle track style 9" housing if you want a full floater. Uauallsy limited to 31 spline, but thats strong enough for most anything.

 

You’re probably who I had in mind when I was thinking back on reading about someone destroying their axle seals after a single day of running on their first day out. I knew the pad kick back was a definite issue hence my mention of how you can grab these things by hand and wiggle the axles back and forth by a fair margin once the brakes are out of the way. Vehicle weight leaning on the axle through a turn doesn't care if the brakes are there, it moves them and then you have clearance btw the rotor and pad next time you need the brakes... kickback.

86TA I had always planned on running 31 splines since I’m not ever doing drag launches on slicks. I’ve looked at building a circle track 9”, already have a bunch on circle track parts in my suspension. It is cheaper but I’d have to a little custom business because it seems they all have a spec wheel stud of 5/8”

 

Nope, hubs are available in 1/2-20 and 12mm. I forget who makes it but there is a bolt in version out there and all kinds of custom options.

 

you can get thicker c-clips to take up some of that slack. knock back isn't a big problem with these brakes on the rears as the calipers slide. they aren't fixed calipers which are much more susceptible. if it isn't a all out race car I wouldn't worry about it.

 

I feel/get pad knockback with floating calipers on the street, it's more of a problem than you think

 

No, its not. you have some other issue with your system. likely your fronts.
but if the rear: undersized cross pin. thin c-clips. slightly undersized axles (flange past c-clip)
knock back free '95 w/ 10bolt c-clip rear:

 

LOL, telling me what I do and don't have. That's funny