24 replies to this topic

[Marc Hoover]

Quality American made front hub for NA and NB cars

20% bigger bearing For details europerf@comcast.net

Tested and tested on my T1 Miata with Big tires, brakes and big horsepower 

Available now 

With or without long studs 

[Andrew Stowell]

How much do they cost?

 

Is anyone interested in trying to change the SM rules to allow these? Everyone has been looking for a solution to failing hubs. Here it is.

[FTodaro]

would need to be submitted to the SMAC do some testing and see if its the right way to go before we could get behind a proposal. 

[davew]

Would be nice if we had pics, or a website or tested on something more than the sellers car

[Bench Racer]

Info only, there is another person with Miata aftermarket hubs.

[Todd Lamb]

Mazda already has some "better" hubs out there right now being tested...SMAC is working on this.

[Caveman-kwebb99]

Mazda already has some "better" hubs out there right now being tested...SMAC is working on this.

 

 

I am fine with us allowing another product but please dont disallow us to use the regular old standard hubs.  I am not finding I have to many hub problems myself.

[Todd Green]

Mazda already has some "better" hubs out there right now being tested...SMAC is working on this.

 

Speaking of which, was there ever a consensus on the early run issues on these and did they make a production change?  Assuming we are talking about their HD Hubs.  Or do they have some öther "better" hubs in the works?

[Todd Green]

Speaking of which, was there ever a consensus on the early run issues on these and did they make a production change?  Assuming we are talking about their HD Hubs.  Or do they have some öther "better" hubs in the works?

Well since no one answered this, I called Mazda Motorsports.  I was told that they did have a small number of people with issues with the early runs and that they modified the races, but have continued to use the same ball bearings that they've always used in these hubs (which are supposed to be a higher grade than stock bearings.)  The production change is from some time in 2014.  FWIW.

[Parity]

The big issue we saw was variation in the races which caused anything from .002" free play to some pre-load. A brand new bearing with any level of free play would fail much sooner than one with say .002-.005 of pre-load. They were grinding the inner faces of the races to produce a more consistent pre-load. Not sure what the results were of that effort.

[FTodaro]

I will let Mark Bennett comment further when he is ready, but it looks like we have had a new issue crop up where people are losing 5th gear in their transmissions. It may be to early to diagnosis it but the hubs and transmission issues are likely coming down to use using too big of a tire.

 

We need to discuss the concept again, of Hoosier developing a 195/50/15 tire.

 

A change like that has to be proposed now.

 

My 2 cents.  

[Jim Drago]

I will let Mark Bennett comment further when he is ready, but it looks like we have had a new issue crop up where people are losing 5th gear in their transmissions. It may be to early to diagnosis it but the hubs and transmission issues are likely coming down to use using too big of a tire.

 

We need to discuss the concept again, of Hoosier developing a 195/50/15 tire.

 

A change like that has to be proposed now.

 

My 2 cents.  

12 plus years in Sm, have yet to lose a rebuilt trans ever... I did lose third gear once in a used box. If the transmissions are built correctly by a qualified person, 99% of the failures are driver related.

 

I have not had any 5th gear failures on any rebuilts we sold at all, last three years in well over 100 transmissions?

Hopefully it isnt something new popping up 

[davew]

Every 5th gear failure I have had has been due to a broken diff balancer. My theory is that the balancer comes loose and the driveshaft starts to whip. Since 5th gear is the back of the trans, it takes the most abuse from the whipping effect. I see this mostly at Road America due to the amount of time at high speeds.I got it approved to remove the diff balancer several years ago for this reason.

 

I agree with Jim, 99% of transmission failures are due to drivers not shifting properly. mostly down shifts. I have had several drivers who would break a trans every weekend. Once they learned how to properly downshift, they have not broken a trans in years. Down shift as late as possible and learn how to heel/toe with the proper blip. Too much is just as bad as too little.

 

Another tip, use the stock shifter and shift ball. I know Jim likes his green eyed monster, but I have found that using a short shifter or an aftermarket (significantly lighter) shift ball will cause poor shifting. Trust the Mazda engineers.

 

Dave

[FTodaro]

12 plus years in Sm, have yet to lose a rebuilt trans ever... I did lose third gear once in a used box. If the transmissions are built correctly by a qualified person, 99% of the failures are driver related.

 

I have not had any 5th gear failures on any rebuilts we sold at all, last three years in well over 100 transmissions?

Hopefully it isnt something new popping up 

As I said may be to early to say, but driver induced yes always, but poor shifting generally results in cracked syncros.  Detonating 5th gear and the counter shaft is something more. Is that just bump drafting or is that a cumulative stress on the weakest part of this box?

 

I don't know just asking the questions.

[Steve Scheifler]

The 5th gear failures, which is what seems to have increased, are not likely from downshifts, or even upshifts for that matter. It's also the simplest to get correct on assembly, I'm told, with no secret treatment or tricks being done. Some failures have included twisted shafts, which isn't easy either. There has been speculation that some failures are from aggressive bump-drafting in fifth, or going off then back on under full throttle. And as Frank said, the extra grip from the tires has been mentioned as possibly contributing.

Or, there has been a coincidental rash of unrelated failures and they will stop as suddenly as they started. Or, these things are getting old and nothing lasts forever, other than a woman's grudge of course.

[Jim Drago]

Or, there has been a coincidental rash of unrelated failures and they will stop as suddenly as they started. Or, these things are getting old and nothing lasts forever, other than a woman's grudge of course.

I tend to think this ^^^

[Tom Hampton]

Jim you mean the "woman's (or womens') grudge"...of course.

[Jim Drago]

 

Another tip, use the stock shifter and shift ball. I know Jim likes his green eyed monster, but I have found that using a short shifter or an aftermarket (significantly lighter) shift ball will cause poor shifting. Trust the Mazda engineers.

 

Dave

 

That is good advice.. many I see are too long and give way too much leverage to people who already are hard on boxes. FWIW.. i spent about 2-3 hours fitting that stupid shifter on my car so that it was the same height as stock, originally it was over an inch taller.

[Todd Green]

issues are likely coming down to use using too big of a tire.

 

It's hard to argue against a stickier tire putting more force on components, but in my experience that isn't the (main) cause of failure.  I've been running R7's on 15x8 wheels and a better suspension that allows 1.5G's sustained over .3 seconds and made it over 38 races (plus TT sessions etc.) including at least 6 rain races where I didn't repack the bearings and just now had one hub start to fail.  Our other car has run 3 full seasons (14+ races per season, TT's etc.) and four 6 hour enduros and the hubs are still going strong.  It's had a mixture of BFG R1's, SM7, and R7's on it.  I honestly have no idea how going by past experience.  I'm hesitant to swap them out for our 6 hour next month, but I know I don't they'll fail a couple of hours in.  If I do, the new ones will probably suffer infant mortality.

 

Anyway I've had hubs fail after half a season while on Toyos.  I personally think the manufacturing of the hubs has more to do with it than the slightly stickier Hohos.   No input on 5th gear as we rarely use it at our track.

[davew]

Virtually every used race trans I take apart has a twisted spline on the lower shaft. The shaft has reverse gear splined to it. Then a non-splined spacer, then 5th gear splined to it. The splines actually twist under the unsplined spacer. I have a splined spacer that I put in my race transmissions that helps save the shaft.