How strong are 28 spline axles??

[70shortwide]

I too am interested in this. I am planning to upgrade, but itd be nice to know the breaking point of what i have...

i suppose it depends on traction, if your gonna run narrow tires and open gears...they might last. if your like me... planning for wide tires and wholeshots, i wouldnt expect them to last long.


this is just my uneducated thought, hopefully someone that knows will chime in

[dantheman71]

Just found this calculator on the Moser website.
http://www.moserengineering.com/Pages/axletech.html

Using 450 ft-lb torque, 2.46 first gear ratio, and 4.11 rear end I got a total of 4094 ft lb. Moser 30 splines are supposed to be good to 6200 per axle. I think I will go with a detroit locker and Moser 28 spline axles and keep my fingers crossed!!

[70shortwide]

how do i find the first gear ratio in my tranny. its a c-6

[mrtleavitt]

400 horsepower with 28 spline axles will be fine. However, if you are building a 4 link rear end you'd better put the 31 splines just for the heck of it. If you're going through all that trouble just go a little extra and then you'll never have to worry or second guess again.

[dantheman71]

70shortwide, I just did a google search to find mine. A C-6 has the same first gear ratio as a C-4 according to what I found (2.46)

I couldn't agree more with your Mrtleavitt. The only problem is I am starting to do crazy stuff like worry about a budget. My 4-link is the Fatman Fabrications kit and it is good but it set me back a lot of cash. The beauty of the kit is I can change rear ends by just replacing the piece that welds onto the rear end. I was thinking I could focus on getting my paint and body work complete and then getting the motor so that actually makes some power. After all this is done I could throw some more money into the rear end, if there is any left.....maybe Santa will bring me one next year.

[averagef250]

You could ditch the 9 inch all together and run a plain old factory 30 spline dana 60 with a powerlock. You won't break the 60 and the 60 robs less power than the 9 inch.

[427]

I,ve been running 28 spline axles in my 68 and its pushing over 500hp with a locked limited slip and haven,t had any problems. I used to drag race it some but I never ran any slicks that would probally twist them for sure. If you dont plan on running slicks you,ll be ok.

[My427stang]

I,ve been running 28 spline axles in my 68 and its pushing over 500hp with a locked limited slip and haven,t had any problems. I used to drag race it some but I never ran any slicks that would probally twist them for sure. If you dont plan on running slicks you,ll be ok.

I agree. I ran the heck out of mine, even with a 375-400 hp 390 with 125 hp of juice on top for years.

No slicks, but varying sizes of mudders, radials and all hard launches. If the tire spins at all the 28 spline wont break. Slick are a different story

With that being said, I doubt the torque of a SBF, even a big one will hit it hard enough to hurt them.

I am too far for you, but if anyone monitoring this one is close enough to Wash DC to pick up a bump Dana 60, 5 lug, I have one disassembled that needs going through. Comes with an open diff, a trac lock and a powerlock.

[averagef250]

I've broken a good share of 28 spline axles in a welded rear with a very mild 351W, 36" boggers in mud/rocks. Went to a 31 spline axle and haven't broken a thing since. I was surprised how easily the 28 spline axles snapped, but traction and multiplied torque in low range are a different story than the rear under a light 2wd pickup with little traction.

Seams that most lightweight drivetrain parts will survive well with small block power. If it's actually feasible to get 400 lb/ft from a N/A small Windsor that torque does not come with the instantaneous potential of a big block/diesel. There's quite a difference between what a 200 pound rotating assembly can do and what a 90 pound one does. Basic laws of physics prevail I guess.

[FORD428CJ]

31 spline 9" will live for sure! I ran a strong Solid Roller 428 for years as an everyday driver. It had 3.50 gears and "NO" smaller then 35" to no bigger then 37" tires on it. Never had a rear end problem. I don't know about 28 spline stuff. All I have ever ran was 31 spline.

[dantheman71]

I was hoping to do some occasional drag racing, possibly with slicks but maybe for now I will just let the tires spin...I was hoping a low stall speed in the converter would be enough to save me but I am probably dreaming. Sticky track + sticky tires = sticky situation for weak axles