Using thunderbird axles
 

Ive read a lot, I know its easy to just buy the axles for 250.00 from Factory 5but the guy at the scrap yard threw in the t bird axles for free when I picked up my diff. Ive heard I can use the outer cvs from the miata, which would be a weak link, Or I can move the strut mount, well to be honest ive heard all kinds of things- So bottom line to use the t bird axles what needs to be done?

Shorter axles & broached hubs.

So, by the time I buy shorter axles/ center shafts and broach the hubs, ill have spent the 250 for the factory five axles that bolt right up? Or do the factory five axles need the broached hubs also?

Believe it or not, the Factory Five deal at $250.00 is cheap. Some have spent thousands on axles. Probably better axles, but still...

Bottom line is you can't use the Tbird axle assemblies, they are simply too long. The FF axle assemblies are the right length, but you still have to deal with the hubs. If you can't do the machine work yourself to modify Tbird hubs to fit the Miata bearings, then you might as well have the Miata hubs broached.

Mike

Besides having the hubs broached, is there anything else that needs to be done to use these axles?

Some spacers.

From the "other" forum:

http://forum.miata.net/vb/showthread...ght=hub+spacer

Wow, 2005, seems like yesterday.

Mike

Instead of broached hubs, why not have a machine shop shorten your Tbird axles and then respline them to match the Miata outer CVs? Then, no need to broach and if you toast the outer CVs, new ones can be purchased and installed without modification. Chances are you will not break an axle.

Gary

Call Monster Miata & get a set of axle shafts & spacers. Send them your hubs, & they will send you a broached set. While you are at it, get a set of their differential hangers. All of this stuff works as a "package" & it fits without having to keep messing with it. As far as price goes? Who cares? I would much rather have something under my car that I could Install once & be done with. Plus, it has been proven to hold up in hundreds of builds.

ford diff
 

i just bought a 8.8 irs ls 3.27. we were goi;ng to install it without a kit, but reading on here it seems axles and a diff hanger kit from monster miata is the way to go. about how much is the hanger kit? the axles seem to be about 250 . also what is a broached hub? nobody i have talked here knows, but i have not talked to a machine shop. this is a track car only and hallett is our home track. we have had a lot of problems with the clutch and trans, but we hope to have a handle on those. when everything works right it is scary fast, but it handles just like it did with the 4 cyl. in it. the main diference is it has a lot more speed in places where it did not before. any comments or suggestions about the diff and axles are welcome

http://en.wikipedia.org/wiki/Broachi...etalworking%29

The above link describes the broaching process. The goal is to enlarge the splined center of the Miata hubs to accept the Thunderbird/Cougar axles.

My opinion is that the 8.8 differential is overkill for such a light car. The advantages of the 7.5 include price, availability, ground clearance, exhaust clearance, axle geometry, & C/V clearance at the rear shocks.

First you might not be able to cut and respline the t bird axles if they taper.check them first.certain ones possibly the ones from the super coupe might be the right ones. Check that first.Then you have to move the shock back if you use t bird ends..I used the big mercury mountaineer ones cut resplined and had the modify the mercury big hubs, big time pain,but it works fine and is about as heavy duty as it gets.

using t-bird axles
 

Thanks for the info, but I just gave up and ordered complete axles from the driveshaft shop. Great service not cheap but they bolted up with no problem. They have t-bird inner cv's and miata outer so I did not have to move the shocks. I saw on line where somebody twisted the outer spline off but he had a lot more hp than I will ever have.

I would think the problem with resplining a axle is the same as the problem with cutting and welding it-you'd compromise the case hardening.

-Jason

i could agree to a point but nothing could be as bad as cutting an axle and welding it, could you imagine all the torque put at the weld, Now if resplined is done properly it is much better than a cut axle.Putting the weight of the miata the tires would spin thus taking most of the stress off most of the drivetrain anyways. You would have to hook up with sticky slicks to create any kind of stress against the drivetrain.I would guess the weakest point probably are the broached hubs, thats why I used big mountaineer hubs and axles and had them cut to fit the 8.8 rear and miata bearings.

My axle shafts are so thick around its actually overkill. My biggest problem is getting the clutch to disengage enough. I have the tko 600 and using a fiero slave and a 7/8 wildwood. I moved the pivot point inward,bled the system back and forward endlessy, and it still just barely releases. The last thing I am in the process now of doing as a last resort is to move the connection lowes on the clutch pedal to gain more travel when I depress the pedal. If this dont work I give up with this and I will try to rig up a cable clutch. This project has been nothing but a pain. and I have built 2 cobra kit cars along with many vehicle mods over the last 30 years. If I had to do this project over again I wouldnt.N othing was made for this project to fit in the vehicle it wasnt made for a bigl engine and anyone who thinks different is dreaming. Theb project is insane.

respline
 

Jason that is what Dutchman Racing told me. So with all that in mind is why I just bought axles from the Drive shaft shop.

So, wait, are the Factory Five axles for use with the 8.8" or the 7.5"? I saw a thread where a guy tried to use them with the 7.5" and they were too short. Are the spacers to fix that problem?

axles
 

I was not able to find out anything about factory five axles. Axles from the driveshaft shop cost 700.00 but they fit perfectly and you don't have to move the shock mounts

I have resplined axles and 20K+ miles on the conversion. No issues with the axles.

FF axles fit well with the 8.8 and broached Miata hubs. Since the 7.5 is slightly narrower, the axles end up too short. The spacers spoken of are for the seal at the hubs, not to compensate for the axle length. I've often thought the 28 spline axle bars at EMPI are worth a look to see if they would replace the FF axle bars.

Mike