Rear axles and Miata hubs
 

So has anyone used the 8.8 conversion axles that mate to the stock Miata hubs? On v8 roadsters site this is the stage 1 8.8 option. The broached hubs are the stage 2. They rate the stage 1 to 400 HP and with the tire width in my opinion being the fuse in the drivetrain I think this may work pretty good. I am trying to keep the ability to get replacement parts almost anywhere and the broched hubs being custom kind of rule that out.


I am just wondering if the upgraded hubs is worth the hassle of having to source custom replacement parts down the line. Opinions from the group?

If you have custom axles, what's the worry if you have custom hubs?

I guess it because I have seen more hub replacements on a Miata than axle replacements. With the hub loads on a track Miata I just want easily sourced replacements. I try to keep my spares as easily sourced as I can. I have had track days end before they start because of a custom one off part being my expensive ticket for a weekend trip as a spectator instead of a driver.

Makes sense. I didn't realize the miata hubs were a source of failure, but I have only a handful of trackdays under me, and none since the V8 conversion.

The Spec Miata guys replace quite a few. I just dont think the hub was ever designed around the G loads that running really sticky race or max performance tires can generate.


I have been searching the site either these axles are a new thing or no one has taken a shot. I have sent a e-mail to the driveshaft shop since they make them to see what they say.

I believe the hubs that spec guys have trouble with is the front ones. In the rear the bearing is the wear point that you would need to replace from time to time and that is stock Miata.

I'm running Martins 8.8 axles in his broached hubs and NAPA wheel bearings behind a warmed over LS that is at least 400 hp. It's been through 21,000 miles of all conditions, loads and launches and have had no issues with the bearings or hubs. I killed an inner CV joint by letting the exhaust cook the grease out of it but had it stayed lubed it would still be going strong too.

Sometimes, bad shtuff happens.
Rear hub and bearing replacement

Hey, recently, a discussion about running Cobra/Tbird hubs came up, just a thought, cobra hubs will probably last longer. There's my shameless plug.

https://www.v8miata.net/v8-miata-dri...stay-diy-2658/

Not trying to be argumentative but that broken hub was a front one. and he said he was doing the rears as a maintenance precaution. I've never seen a rear hub/bearing failure personally.

Steve,


You are right the rears are not as prone to replacement as the fronts. But I have seen it happen. I'm just trying to keep parts sources as easily accessable as I can. After a lot of builds I have found the more stock parts I can use the better for down the line. It is a personal preferance for me.

I've also never seen a rear go out on anyone, v8 or stock. I have seen the fronts go and have made a point to replace them every two years with new ones that I've repacked with redline cv2. For the rears I let them go four years since popping out and replacing the bearings is such a pain (heat and cool, use a press, etc.).

The ones I just changed out were original to the car with 187000 miles on them. The last 20000 were with the V8 so I figured it was about time. The fronts smelled like an old bbq grill when I pulled them so I know they were pretty much toast. I'm not going to rebuild them for this reason. The oem replacements were significantly more "beefy" than the original 1994's which made me feel a bit more secure. The rear bearings were rough looking but nearly as bad as thd front. They still smelled like grease.
I think the fact the fronts have to deal with the forces associated with turning as well as the higher heat of the front brakes as opposed to the rears helps wear them faster. I would not worry about the rear hubs being a wear item.

-Jason

To piggyback on what I just said, the one component of the rear setup that did wear significantly in the 20k miles as a V8 were the aluminum spacers Monster Miata uses to seal the rear of the hubs in the Miata spindles. When I took everything apart I found them very scored and the seals they seal against completely blown which had permitted a significant amount of dirt into the bearings. Instead of just replacing the seals (very easy and dirt cheap) I also had a local machinist replicate the spacers in steel and micropolish the outer surface for me. I can have him make up more sets if anyone wants to go that route. I'd recommend it on any car that's being tracked or doing more than 2000 miles a year. At the very least use new seals and polish up the MM "stock" spacers before installing them.
-Jason

Interesting. When I had my shaft out in June I didn't see any wear at all on the spacer. It had about 18K miles on it at the time and 21K now. Maybe you got a bad batch?

Maybe. They didn't seem quite finished which could have caused the issue. Its also possible that Martin's improved the quality of this part since my kit was put togther 5 years ago. I know we recently rebuilt a car which was built with a kit from three years ago and the radiator was of much higher quality (Howe as opposed to Sultana).

-Jason

I contacted Martin recently with a question I had with my axles and what thickness spacer he recommends. He said the axles he sells now dont require them at all and I must have the older axle setup.

Cool that he's still evolving/improving pieces. I got my rear and axles in July/14. They still came with the aluminum spacers. Hopefully some pics will show up of the new design. Just curious.

Who is this Martin you speak of? Link to his axles for sale please?

WHATTTT???? The guys converted over a 100 Miatas to v8 power, sold many hundred kits and the V8 Miata business is built on the foundation he's a part of.

I suggest a thorough reading of the link tbone put up.

I did just revisit Martins site and didn't see any reference to the new LS engine subframe I understand he now has. Hopefully that changes soon.

I saw it on FB. Sent an email with questions last week. No response.