how fast on 30 spline axles

[chasmat2316]

how fast can you go on a full weight GN with Moser 30 spline axles safely?

 

[bison]

how fast can you go on a full weight GN with Moser 30 spline axles safely?

Cotton ran low 9's high 8's for a long time on them. The ring and pinion is the fail point. Ive got about 400 passes on a set of 28 spline Moser axles in one car. About 40 with the t-brake. I'm still waiting for that rear to explode. It does have a girdle and was nice and tight last year when I inspected it.

 

[chasmat2316]

how fast do you 60 ft?

 

[HelloBozos]

I just wasted my currie 9", was just rebuilt too...Zero track time,only street play,the gears burnt an knife edged, found the bolt-in currie 9"s are only good to 435hp...lol,my axles are being checked for twist as i type this,Now building up the unit to handle least 800hp...(more money)

Enjoy!

 

[bison]

how fast do you 60 ft?

Not that fast maybe 10-15 in the 1.45-1.5, 30-40 in the 1.50-1.6, many in the 1.55-1.65 range. Axle failure isn't common with replacement axles. I've seen several sometimes repeated ring and pinion failures in cars that run low 9's or faster.

 

[turbo nasty]

Mosers axles tend to roll/twist where the stockers just snap. Bison is right on the ring n pinion

 

[skew]

Has anyone seen a failure from the 30 spline posi unit before the axles or ring and pinion have issues?

 

[jdpolzin]

I dont really understand the axle spline count debate sometimes. I dont really see why a higher spline count would equal higher HP abilities. I personally run a 35 spline Wavetrac center section in a 9" so I cant really talk but as the axle spline count raises, gear or tooth size decreases. I'd like to see some real world testing on different spline count axles with the same pinion size. I'd put my money on it that the lower spline count axles will hold up just as well if not better than the high spline count.

 

[bison]

I dont really understand the axle spline count debate sometimes. I dont really see why a higher spline count would equal higher HP abilities. I personally run a 35 spline Wavetrac center section in a 9" so I cant really talk but as the axle spline count raises, gear or tooth size decreases. I'd like to see some real world testing on different spline count axles with the same pinion size. I'd put my money on it that the lower spline count axles will hold up just as well if not better than the high spline count.

The spline count isn't as important as the metallurgy and heat treat imo. If the metallurgy and heat treat are consistent the diameter between the splines could be measured to give an indicator of more potential strength. Usually more splines equals larger diameter. It's only
as good as it's weakest point.

 

[87-WE2]

This would be correct. I'm not an engineer, but I've been in the steel business for 18 years. It's not as simple as spline count. Exactly as bison says, it depends on the metallurgy of the steel. Steels have progressed quite a bit in the 25 years since our cars were made. Higher strength steels and better heat treating processes have become not only avalable, but cheaper to utilize. There is science to the number of splines though. The yield strength of the steel has to be taken into account. The higher the yield strength of the steel, the stronger the axle. For instance, 28-splines that have a 30,000psi minimum yield strength won't support the torque that a 28-spline with 50,000psi steel will. A trick to getting better performance is to add splines, which spreads the applied force over a greater surface area of the steel. However, there is a limit to how small each spline can be without failing. The total applied HP or torque must be taken into account to be sure that the strength of the individual splines are not overcome. The axle companies no doubt have a sizable design factor built in to the axles as well.

You might be surprised at how much pressure and tension steel can withstand! In oilfield applications, it would not be unheard of for us to have a threaded connection with an effective cross sectional area of only 21 sq. in to support a string of pipe weighing 2,000,000 lb. that it almost 5 miles long from top to bottom.

I'm removing my pocket protector now!

 

[charlief1]

I dont really understand the axle spline count debate sometimes. I dont really see why a higher spline count would equal higher HP abilities. I personally run a 35 spline Wavetrac center section in a 9" so I cant really talk but as the axle spline count raises, gear or tooth size decreases. I'd like to see some real world testing on different spline count axles with the same pinion size. I'd put my money on it that the lower spline count axles will hold up just as well if not better than the high spline count.

A 26, 28 or 30 spline axle shaft has a different diameter Jeremy, not just the amount of teeth on the shaft. The larger diameter of the shaft and the larger count of the splines means more surface area so it's stronger. If you look at the strength rating on a 3/8" bolt if you go to a fine thread count over a course thread count the strength goes up because of surface area required to pull the thread out. Hope that helps you understand.

 

[steve hughes]

I used to run a gn rear with 30 spline mosier axles and a 30 spline eaton posi. When i got the car to 60 foot in the mid 1.3's the posi lasted about 6 passes before the spider gears exploded. I then went with a spool. Got the car running 9.30's with 60" from 1.27 to 1.32 . Broke atleast one ring and pinion a year. Never broke an axle, but the splines did start to twist and the axles tubes bent 3 times before the last ring and pinion went and took out my 400 turbo with it. 100's of passes on the axles even after they started to twist. If you plan on lots of power and low 60 " times save your money and go with a 9 inch.

 

[chasmat2316]

I used to run a gn rear with 30 spline mosier axles and a 30 spline eaton posi. When i got the car to 60 foot in the mid 1.3's the posi lasted about 6 passes before the spider gears exploded. I then went with a spool. Got the car running 9.30's with 60" from 1.27 to 1.32 . Broke atleast one ring and pinion a year. Never broke an axle, but the splines did start to twist and the axles tubes bent 3 times before the last ring and pinion went and took out my 400 turbo with it. 100's of passes on the axles even after they started to twist. If you plan on lots of power and low 60 " times save your money and go with a 9 inch.

thank you for the info - it was the first real world response!

 

[jdpolzin]

The spline count isn't as important as the metallurgy and heat treat imo. If the metallurgy and heat treat are consistent the diameter between the splines could be measured to give an indicator of more potential strength. Usually more splines equals larger diameter. It's only
as good as it's weakest point.

Gotcha! I have never used anything but 28 spline axles on an 8.5 or 35 spline axles on a 9". I didnt realize the diameter grew as the spline count grew. Learn something new everyday!

 

[WSLN 6]

Wait a minute! Are you saying my stock axles,rear, and driveshaft are in danger? Lol

 

[coach]

Jeremy,
The splines are all about the same size. In order to get more of them, the diameter has to get bigger. The bigger the diameter, the better heat treat they can get into the axle. The bigger the shaft the stronger it will be.
The splines on a manual tranny shaft are an exception to this rule. There are fine spline and course spline shafts.

 

[northerngn]

Gotcha! I have never used anything but 28 spline axles on an 8.5 or 35 spline axles on a 9". I didnt realize the diameter grew as the spline count grew. Learn something new everyday!

stock 28 spline vs Strange 33 spline

 

[HelloBozos]

I just wasted my currie 9", was just rebuilt too...Zero track time,only street play,the gears burnt an knife edged, found the bolt-in currie 9"s are only good to 435hp...lol,my axles are being checked for twist as i type this,Now building up the unit to handle least 800hp...(more money)

Enjoy!

All done!!! Now Let's see how this unit holds up...Went with whole new case (bonus added traction control to my XFI2.0)

Enjoy!