Mach 1 28's vs 31's

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All I can say is that if you plan on serious launching with slicks, you would be very smart to upgrade your axles to 31 spline. And since 31 spline axles are the same diameter as 28 spline axles, the upgrade shouldn't be too painful. You will need a 31 spline differential and possibly new ABS excitor rings, which are cheap.

For any that want to order new 31 spline axles for their Mach1, I highly recommend contacting Moser. All you need to tell them is that you want 31 spline axles for your 2003 or 2004 Mach1. You'll need to specify which differential you plan on running and whether or not you plan on keeping your ABS. Roughly $250 and 2 weeks later, you'll receive these in the mail:

RearEndMoser.jpg
 
If your going to run a mach with drag radials...you'll need the 31 spline..otherwise your sitting on a time bomb. For some reason since 2001 the 8.8 mustang rear ends(gt's break them all the time as well with little or no mods) with 28 splines have been breaking like tooth picks.

I guess ford went with a cheaper cast or something.


I put 31 splines in my mach, and I still broke the 31 spline differental and spider gears.
:(
 
I'm sure thew stock ones are weak. But what tells you that aftermarket 28's aren't good enough? Has anyone ever destroyed aftermarket 28's. I have yet to find one honest person who has. And to answer the question as to why not just go with 31's, I have to upgrade the diff. to 31's also. Not just the axles which doubles the cost. I don't mind paying that, but I want to know for sure it's needed.
 
rdksek844 said:
I'm sure thew stock ones are weak. But what tells you that aftermarket 28's aren't good enough? Has anyone ever destroyed aftermarket 28's. I have yet to find one honest person who has. And to answer the question as to why not just go with 31's, I have to upgrade the diff. to 31's also. Not just the axles which doubles the cost. I don't mind paying that, but I want to know for sure it's needed.

It's probably true that aftermarket 28 spline axles are sufficient for our stock power levels, but if you're going to do the rear end work yourself, and can afford the extra parts, you might as well make it bulletproof and go for the extra performance while you have everything apart. This way, if you add a power adder in the future, you'll have a rear end that is more reliable.
 
wurd2 said:
It's probably true that aftermarket 28 spline axles are sufficient for our stock power levels, but if you're going to do the rear end work yourself, and can afford the extra parts, you might as well make it bulletproof and go for the extra performance while you have everything apart. This way, if you add a power adder in the future, you'll have a rear end that is more reliable.

O.K. I have heard that alot. But every time I ask the question of "What is the limit of aftermarket 28 spline axles?" all I get is the same response: see above. I want proof or at least someone to tell me that they have broken aftermarket 28 spline axles. I want to know what the difference between 3 splines.
 
Well, I know that it didn't take me long to break my factory rearend. I never bolted up a set of DRs either, just had some 275 BFGoodrich KDWS tires and I broke the rearend within four months of having the car. It started to whine early on and finally blew out one day when i was on it. I don't know about aftermarket axles but I know once I start doing work on the rearend I'm getting 9" rearend with 31 splines
 
djlethalwang said:
Well, I know that it didn't take me long to break my factory rearend. I never bolted up a set of DRs either, just had some 275 BFGoodrich KDWS tires and I broke the rearend within four months of having the car. It started to whine early on and finally blew out one day when i was on it. I don't know about aftermarket axles but I know once I start doing work on the rearend I'm getting 9" rearend with 31 splines

Well you are entitled to spend your money how you see fit. I don't blame you for shooting for the moon if you are going that route anyway. But in my case, I am just trying to understand the limits of the aftermarket 28's and why they are not as good as the 31's. I have a hard time believing that 3 splines are making that much of a difference. I want someone to prove me wrong, so I can justify shelling out the extra cash. Anyone?
 
rdksek844 said:
Well you are entitled to spend your money how you see fit. I don't blame you for shooting for the moon if you are going that route anyway. But in my case, I am just trying to understand the limits of the aftermarket 28's and why they are not as good as the 31's. I have a hard time believing that 3 splines are making that much of a difference. I want someone to prove me wrong, so I can justify shelling out the extra cash. Anyone?

I respect the approach you are taking towards spending your money on upgrades. However, I don't think you're ever going to get a satisfying answer to your question of how much an aftermarket 28 spline axle can handle, simply because there are just too many variables involved when an axle does decide to snap.

I think your best bet is to call Moser and see what they think. They probably snap axles on purpose with machines just to see how much of a beating they can take. A drag racer that snaps an axle at the track can't tell you exactly how much torque it took to break, and how much stronger the axle needed to be in order not to break.

If you aren't planning on a power adder, then I bet you won't be able to snap a hardened (or aftermarket) 28 spline axle. And especially, if you aren't going to run slicks, then you probably don't need to replace your axles. I don't know about you, but "probably" isn't good enough for me. I would want to be certain about having axles of sufficient strength. I'm sure all of us know here, but snapping a c-clip axle means your rear wheel comes flying off along with part of the axle.
 
wurd2 said:
I respect the approach you are taking towards spending your money on upgrades. However, I don't think you're ever going to get a satisfying answer to your question of how much an aftermarket 28 spline axle can handle, simply because there are just too many variables involved when an axle does decide to snap.

I think your best bet is to call Moser and see what they think. They probably snap axles on purpose with machines just to see how much of a beating they can take. A drag racer that snaps an axle at the track can't tell you exactly how much torque it took to break, and how much stronger the axle needed to be in order not to break.

If you aren't planning on a power adder, then I bet you won't be able to snap a hardened (or aftermarket) 28 spline axle. And especially, if you aren't going to run slicks, then you probably don't need to replace your axles. I don't know about you, but "probably" isn't good enough for me. I would want to be certain about having axles of sufficient strength. I'm sure all of us know here, but snapping a c-clip axle means your rear wheel comes flying off along with part of the axle.

I think you are exactly correct. My purpose in this thread is to ask the users for their input. I really want to avoid getting a bias response from an axle manufacturer, but I think you are right, they may be my only source for my answer. Oh and how do you like the 4.30's?
 
rdksek844 said:
Oh and how do you like the 4.30's?

I absolutely love them. In my opinion, there is a lot of truth to the don't fear the gear expression. I would never go back to the stock 3.55's. And I think the gears are the best performance mods available, aside from power adders. They are the best bang for the buck too. They really wake these cars up.