80 replies to this topic

[Brandon]

Yo Saul!  You got some free time on your hands?  

 

I see some minutiae for you to work through with this idea: put clay between the races & torque to increasing values & measure the clay thickness at each level.

See if there is at some point the clay thickness approaches zero.

 

Think of it like building a 4-cylinder engine and PlastiGauging one main bearing at a time.

[chris haldeman]

No need for plastigague. If the inner races are not touching there is no play. How could there be???

[chris haldeman]

Point of fact I run torque at 80-90# on my hubs and have not seen a failure ever. Increasing the torque is simple compressing the inner races and potentially creating distortion. The inner races are touching each other at near zero torque. If there is play they are touching too soon

[Bench Racer]

The good part of several folks thinking, inspecting, measuring, and throwing out their info (I discredit no one's info, maybe a bit from AW33COM ) is sooner or later something comes to the surface.

Saul, you may have provided this info, Frank made a zero inner race gap comment along with others. I have measured one hub for inner race end gap and found there was .005/.006 inches clearance. Keith made a comment that when he was checking inner race end gap the gap was the same as the thickness of a SunFlower seed bag. I collected a a failed hub from Jared Gerber at the Blackhawk Farm Major race earlier this year, inspected the outer races, found nothing, measure the balls to 4 places, found nothing. the grease was original. I had previously looked at the ends of the inner races of the non-falied hubs I have taken apart, perfect smooooooooooth finish on the hub inner race ends. I looked at the ends of the inner races of Jared's failed hub bearing and guess what, both inner race ends are spalled. Will those of you with failed hubs please look at the ends of the inner races and check for smoothness or spalling and report back your inspection results. Betcha many failed hubs have inner races with spalled ends. Has anyone ever machine ground.030 inches off the inside end of each bearing inner race when the hub was new or before the failure? Hub bearing life may be longer.    Saul, Michael Novak (old bearing guy), anyone???

Johnny, that's all for now.

[FTodaro]

Installation note:

 

they say that you should NOT grease the spindle when installing. some times the hub does not like to slide home. does anyone lubricate the spindle before you install the hub? 

[davew]

If the hub does not slide on, you have some sort of interference, corrosion, knicks, deformaty, etc. A light sanding will probably cure the problem.

 

The inner races have to touch. If not, the entire force from the spindle nut would be pinching the ball bearings. The inner races do not spin, they are held in place by the spindle nut.

 

Dave

[mellen]

If the hub does not slide on, you have some sort of interference, corrosion, knicks, deformaty, etc. A light sanding will probably cure the problem.

 

The inner races have to touch. If not, the entire force from the spindle nut would be pinching the ball bearings. The inner races do not spin, they are held in place by the spindle nut.

 

Dave

Dave is correct. The inners should NOT spin. the outters and balls are moving around the still inners.

[FTodaro]

Dave is correct. The inners should NOT spin. the outters and balls are moving around the still inners.

Mellen we know your Balls are moving around your Inners, you do not have to post that up. seriously, how bad was your bearing failure during the race Sunday? left/ Right Race destroyed?

 

Failures i have seen:

1) hub gets loose wobbles when you grip tire 12 and 6. I have ran and repacked those with a slight movement and had not issues for a short period of time, at some point the play gets to big not worth risking it

2) noise and thumping the race is coming part, pitting,, hub is toast and needs replaced asap

3) the plastic retainer Holding ( mellen's balls) comes apart, if caught soon enough the hub does not destroy itself and my live another day. ( could be caused by cracking the ball retainer when repacking)

[Johnny D]

Mellen we know your Balls are moving around your Inners, you do not have to post that up. seriously, how bad was your bearing failure during the race Sunday? left/ Right Race destroyed?

 

Failures i have seen:

1) hub gets loose wobbles when you grip tire 12 and 6. I have ran and repacked those with a slight movement and had not issues for a short period of time, at some point the play gets to big not worth risking it

2) noise and thumping the race is coming part, pitting,, hub is toast and needs replaced asap

3) the plastic retainer Holding ( mellen's balls) comes apart, if caught soon enough the hub does not destroy itself and my live another day. ( could be caused by cracking the ball retainer when repacking)

 

So what are you tqing too ??

J~

[DrDomm]

My father-in-law who prepares a GT2 Nissan laughs at me every time I torque my hubs all the way up to 120.  My assumption is that Mazda specs a higher number because they don't expect customers to repack and retorque them every few weeks.

[FTodaro]

So what are you tqing too ??

J~

125-135

[Johnny D]

There is a reason the spec calls out for that. It's the position of the inner ways in relation to the the balls and outters.

as noted earlier. .003" for every 10# ??

 

Just reading what MSP told Brandon and the SKF spec that AW33 posted (159~216), this needs to be correct, IMO.

If your not having a problems, then you can listen to Father-in-Law all you want.

 

And Frank that sounds too low.

J~

[SaulSpeedwell]

40 ft-lbf diff is a live or die.

 

 

Here's a fact: If and when the nut stops TURNING, the reading on the torque wrench becomes meaningless, or at least misleading. Torquing an oil-wetted cylinder head bolt is NOTHING like torquing a dry hub nut where we expect almost no "stretch" (strain) in the joint.

 

"Greased" fasteners will achieve higher clamping force for a given torque - sometimes this is good (i.e. our eccentric alignment bolts, which we KNOW need - and tolerate - much higher "torque" than the FSM-spec), and other times it is bad. .

 

The post about the MSP hub having play until 160 ft-lbs is REAL interesting. IF the play is a cause of the short bearing life, and IF they are replacing the balls such that the bearing fit is being altered, THEN this torque spec issue would seem to be a big deal.

 

I've never seen play when installing a bearing, and I've never seen a bearing that lasted very long once it developed play, and I've never seen play be caused by something other than catastrophic failure of the races (90% of the time) and balls (<10% of the time).

 

In short, this 2014-era "play" seems to be entirely different in nature and cause versus the 2002-2010 "play" that I/we were familiar with???

[Johnny D]

One other thought is if you replace your balls with higher precision and their different in size, the spec tq could be off.

I would guess larger ball would be less TQ.

 

So what do you have to lose, tq higher and see what you get. 150+

J~

[ChrisA]

Just reading what MSP told Brandon and the SKF spec that AW33 posted (159~216), this needs to be correct, IMO.
If your not having a problems, then you can listen to Father-in-Law all you want.
J~

216 is for the Rear axle.

[Johnny D]

My bad, I think were both off it's Nm ft-lbs. Rear is 235ft lbs for a 99?? 

 

http://www.skf.com/b...6360/457377.pdf

 

Front proc. Rear proc.

Make/ or torque or torque

Model Year ft-lbs/Nm ft-lbs/Nm

 

 

 

Miata .....................................1999-2003......... 159/216[87] 235/319[68]

1990-1997......... 159/216 217/293[88]

[ChrisA]

^ Ah, that's it! I remembered the second number referred to something different. Just didn't remember well enough to be correct.

[Bench Racer]

 

and I've never seen play be caused by something other than catastrophic failure of the races (90% of the time) and balls (<10% of the time).

 

Not looking to argue, because you have fondled way more failed hub/bearings than me. I have only fondled one (1) failed hub. I'll take Jared Gerber (#9) and his crew guys word that the hub was loose when it was woobled by griping at 12 and 6 o'clock. This hub has no identification number. This hubs outer races are not a visiual failure, the balls are not a visual failure, the bearing cages are not destroyed/look good, the inner races look good except the ends of the inside ends of the inner races are spalled. The ends of the two inner races are spalled which without doing further checks means the inner race ends have been touching while under load. Here is a comment from my post #24,  I looked at the ends of the inner races of Jared's failed hub bearing and guess what, both inner race ends are spalled. Will those of you with failed hubs please look at the ends of the inner races and check for smoothness or spalling and report back your inspection results. Betcha many failed hubs have inner races with spalled ends. There have been 189 peeks at this thread since I left my pc this morning and no one has responded if their failed hubs have inner races with spalled inside ends ends. There are many contributors to these hub/bearing failures. With no disrespect to anyone or anyone's comments, I do not believe these hubs/bearing balls/bearing inner races were designed with the parameter that when under the specified torque load the inner race inner ends wold touch. Think about the tolerance costs to achieve such a feet. Vehicle bearings with real outer races have been around forever and the inner races when torqued to specification never touch.

Trust me, I'm going to grind .030 inch off one end of my inner races there by eliminating one of the bearing failure contributors. Oh, that would be illegal, I can't do that. 

[Michael Novak]

I will look over the couple I have left at work tomorrow morning. I as much as I know better have been filling the garbage up with them. I know very little about bearings except my ability to wreck them in hubs as go late. We will measure and document what little I have.

[Johnny D]

Thinking... do you want a gap between the outer inner race (nut side) and the inner, inner race (hub side) ??

 

If there's no contact / tq, wouldn't the inner, inner race spin because nothing is holding it?

If you know what I mean.

J~