StraightTimeStirrups

How much HP/Torque can the various axle sizes take on Slicks at the track with perfect traction in an Stock Weight F-Body?

I contacted Mark Williams and they say that they have no data for the 31 Spline Axles they manufacture. I was stunned to find out that they cannot quantify any data on their axles that they are selling! I have been going back and forth with them for 3 days now on the matter! Stunned to say the least!

So what are your real life experiences with axle Strength for the various axle sizes?

28 Spline
31 Spline
33 Spline
35 Spline
40 Spline

How much can they withstand with a Axle Type (10 Bolt, 9" etc.),Type of Diff (Spool, Locker etc), Perfect Traction and 3500 pound F-Body, State Your Gear Ratio, Stall if Auto, Trans Braked etc?

Joe

MeentSS02

iTrader: (11)

See all those things at the end of your post? Those are called variables, and there are too many listed for Mark Williams to give you good data. That's why they aren't giving you any numbers - they could tell you their axles are good for 1000 HP, but in what? A 2,500 lb race car with an automatic transmission? A 4,000 lb tank with a manual and a stiff clutch side stepping at 8,000 RPMs? They likely don't have anyone in their shop running your exact setup, so I don't blame them one bit for not quantifying things for you.

I think a better question to ask them is if they will stand behind them if they break at your power level with your setup? What rear end are you even running, the stock 10-bolt?

StraightTimeStirrups

How are they going to be able to answer that when you are asking the same question in a different manner?

As a matter of fact, I even did ask them that and gave them HP/Torque Ranges in 50HP/Torque increments to see if they could tell me at what point I should go from say a 31 to 33 or 35 Spline Count axle and got the same answer, "We have no data for 31 Spline Axles!"

I gave them my set up exactly down to everything except Dyno HP/Torque! That is why I am asking the questions here because I cant get an answer from them and we have a group here that has run as many varied set ups in these cars as one can imagine!

What is shocking to me is that a company that has been in business over 40 years cant give even a ballpark estimate on axles strength for our cars! I am sure they have a ton of real world experience dealing with cars in the 3000-4000 Pound weight range!

Joe

MeentSS02

iTrader: (11)

There's a huge difference with my question: if a company is willing to stand behind their product, then your power level and combo won't matter. If it breaks, they replace it. If you are talking a 31 spline axle, you are likely looking at a 9-inch, and that combo should handle everything you can throw at it if your mod list is accurate.

And you still didn't answer my very basic question: what rear end? If you are running a stock 10-bolt, I don't think you'll find anything over 28 spline. 9-inch rears typically start at 31 spline, but I think some of the newer diffs are 35 spline. 12-bolts typically come with 33 spline, and the S60s seem to favor 35 spline.

StraightTimeStirrups

I had to add this here because I replied within your quote.

MeentSS02

iTrader: (11)

You'll have better luck searching around in the drag racing tech section:

https://ls1tech.com/forums/drag-racing-tech-34/

And the reason I keep asking about the rear end type is because you will be limited by whatever you have (or put) in your car. Por ejemplo, you won't find a 40-spline axle that will fit in a stock 7.5"/7.625" 10-bolt...at least not that I'm aware of. I've also not seen f-body 12-bolts offered with anything less than a 33-spline...that was my only option when I ordered mine years ago.

IMO, you'll be more limited by your differential choice than axle spline count...figure out what diff you want to run, figure out what spline counts they offer for your application, and go from there.

StraightTimeStirrups

Yo Comprende! I did a search and in 6 pages of threads no one addressed the question I posed when one should step up to a different spline count based on HP/Torque Requirements for our cars.

02SS#214

iTrader: (1)

I'll help you out with the 10 bolt... they won't handle **** withought breaking, lol.

02SS#214

iTrader: (1)

To the OP... are you asking all these variables so you can decide which rear end you should go with?

MeentSS02

iTrader: (11)

From the searching I've done in this section, it looked like quite a few people have twisted their Moser axles, and it also looked like Moser didn't offer a warranty of any sort on anything below a 33-spline axle. If you went with the higher spline counts, it looked like they had a 10-year warranty, hence why I asked about what Mark Williams was willing to stand behind. If they don't offer a warranty of any sort on their 31 spline axles (which wouldn't be surprising since they didn't have data), then your best best is to go with something that does have a warranty.

As long as you aren't unnecessarily limiting your diff selection, there's no reason in my mind to not go somewhere in the 33-35 spline range just for good measure. Lots of diff options available for the different rears out there, and it looks like it took one dude (Fireball) about 1700 HP to twist a 35 spline unit in his 3,500-ish lb car.

StraightTimeStirrups

Actually, no but it may help others. I have decided to personally go with a 9" and bought a Ford Nodular Center Section with a Detroit Locker 4.86 Gear (1/8 Mile) with 31 Spline Axles. I will either have to have the stock axles shortened and resplined or order new aftermarket axles. My engine is tame compared to others but when I went looking for answers I couldnt find any and that is why I posted my questions.

I am not so much concerned for my power levels but thought this might be a great help for others with more HP/Torque in the future.

Joe

02SS#214

iTrader: (1)

ok. I have a MWC Fab9 that is shortened 1" on each end. It has Strange 33 spline axles, Richmond 4:10 gears, Strange Light weight spool, Strange aluminum center section and Chromoly yoke. I'm looking at taking out the spool and buying a wavetrac now for better street manners

stevieturbo

I twisted a few Moser shafts on my 8.8

Timeline...

28 spline thin shafts, never twisted
28 spline large diameter shafts with bigger bearings. twisted
31 spline shafts ( basically same as above ) twisted.

So there are many more variables. I think the long thin shaft had more flex hence the smaller 28 spline never twisted. At least they didnt twist at the splines. The shafts with a stronger main bar, they all twisted at the splines.

Switch to Mark Williams Masterline 31 spline shafts, no twisting. The quality of these is far superior to the cheap Mosers