47 replies to this topic

[AW33COM]

I had to use heat on one of the hubs to get it off

 

Why?

[Bench Racer]

Frank, I can't stand it any longer. Where the hell did that rusty hub come from. I thought the two of you Buckeyes were well connected to a parts source.

[Ron Alan]

Why?

My guess is not to get the hub out but to get the race off that was stuck on??

 

Or maybe it was to get the axle out of the hub?

[FTodaro]

Frank, I can't stand it any longer. Where the hell did that rusty hub come from. I thought the two of you Buckeyes were well connected to a parts source.

My nick name when growing up was "Rusty Hub"... Wait for it....

 

Yes I have a well supplied parts Source but have you seen his prices, you need a small inheritance to play on that Street.

 

My guess is not to get the hub out but to get the race off that was stuck on??

 

Or maybe it was to get the axle out of the hub?

Ron you got it, i had a hard time getting the half shaft out of the hub and used a little heat to get it off.

[Muda]

I was picturing someone heating a hub so that it was glowing red in order to get the axle out.  

[AW33COM]

The race sits right against the hub and there is no easy way to pull it off.  You had to use a lot of heat (north of 500F) to be able to slide it off.  You could just try to reuse the old race, or use the air hammer (can be done, but nasty) to start it slide off.  It's a good thing to have a spear hub ready when you rebuild the rear knuckle to make the whole thing easier.

 

Heating the race on that hub renders the whole thing useless, and that is exactly why your hub broke.   And for that matter you should never (without some exceptions) reuse any heated parts in a race, or street car. 

[Keith Andrews]

The race sits right against the hub and there is no easy way to pull it off.  You had to use a lot of heat (north of 500F) to be able to slide it off.  You could just try to reuse the old race, or use the air hammer (can be done, but nasty) to start it slide off.  It's a good thing to have a spear hub ready when you rebuild the rear knuckle to make the whole thing easier.

 

Heating the race on that hub renders the whole thing useless, and that is exactly why your hub broke.   And for that matter you should never (without some exceptions) reuse any heated parts in a race, or street car. 

 

 

WOW 

[Ron Alan]

The race sits right against the hub and there is no easy way to pull it off.  You had to use a lot of heat (north of 500F) to be able to slide it off.  You could just try to reuse the old race, or use the air hammer (can be done, but nasty) to start it slide off.  It's a good thing to have a spear hub ready when you rebuild the rear knuckle to make the whole thing easier.

 

Heating the race on that hub renders the whole thing useless, and that is exactly why your hub broke.   And for that matter you should never (without some exceptions) reuse any heated parts in a race, or street car. 

The first time I did this I used a grinder and cut the race,,,pain in the butt and a few marks left on the hub

 

Since then with a little patience I've gotten them all off by starting with a sharp but thick bladed type putty/chisel. With a hammer you force the blade between the race and hub a little at a time all the way around. Once you get it separated by the blade thickness(2mm) you can use your weapon of chose to pry then tap the race off. Or worst case if you cant get completely off...its a lot easier to cut once its away from the hub shoulder.

[Muda]

Used to reuse hubs on the 1.6.  The chisel-then-puller method works OK.  But given the loads the Hoos are putting on things I now go with new hubs when I rebuild.  Always wonder whether a 20 yo, rusty OEM hub is stronger than the Chinese stuff you buy today.  So far, no problems.

[Ron Alan]

Used to reuse hubs on the 1.6.  The chisel-then-puller method works OK.  But given the loads the Hoos are putting on things I now go with new hubs when I rebuild.  Always wonder whether a 20 yo, rusty OEM hub is stronger than the Chinese stuff you buy today.  So far, no problems.

I figure a street car used hub should work  So far so good

[FTodaro]

The race sits right against the hub and there is no easy way to pull it off.  You had to use a lot of heat (north of 500F) to be able to slide it off.  You could just try to reuse the old race, or use the air hammer (can be done, but nasty) to start it slide off.  It's a good thing to have a spear hub ready when you rebuild the rear knuckle to make the whole thing easier.

 

Heating the race on that hub renders the whole thing useless, and that is exactly why your hub broke.   And for that matter you should never (without some exceptions) reuse any heated parts in a race, or street car. 

I did not use heat to get the race off, I used heat to get the half shaft out of the hub.

 

I normally use a chisel to move the race enough to get a puller on it it, and press it off.

 

If that was the hub i used heat on, then the failure was right where i used heat.

[LarryKing]

I did not use heat to get the race off, I used heat to get the half shaft out of the hub.

 

Frank, you need a bigger hammer.

[AW33COM]

I did not use heat to get the race off, I used heat to get the half shaft out of the hub.

 

Sorry, too much vodka over the weekend.  I did not read that right. 

 

You still should never use heat to pull the half shaft as that for sure will heat up the hub to a point where you run a chance of making it weaker. 

[steveracer]

Bearing splitter and a press.

 

Done. Quickly. No damage.

 

Only hub issue I've had was when I bashed it into the concrete rail @ MSRH.

[john mueller]

Bringing up an old thread here...

 

 

I think I heard there were three or four rear hub failures in the 2013 25hr...  Seems to me that these parts are starting to see an rise in failure as grip increases and they get more miles on them (some are as much as 24yrs old).

 

For Non-SM racing: Does anyone know of a machine shop or manufacture making custom rear hubs?  5-Lug variety?  Info on anyone who is marketing them would be greatly appreciated.

[Alex Bolanos]

Yes, www.v8roadsters.com makes them.  I also believe they're working something up for Spec Miata as well.

[Brandon]

What

The

Fudge?

 

R.G. Bargy get into the same vodka as AW33COM?

[SaulSpeedwell]

The rear hub failure is not "new" - although it would make sense that bigger, wider, stickier, heavier tires than the old RA-1s would accelerate the failure. 

 

Inspecting and preventively replacing the hub is important - and, for reasons I don't fully understand, a cracked hub would CAUSE snapped studs.  (Yes, the cracked hubs would CAUSE snapped studs, not the other way around - but that was back before ARP made us 1.8 rear studs, and so we were using those crappy NAPA Mercedes studs.  I don't think this scenario will happen with ARPs.).  I think the cracked hub would flex and cause one stud to take hell - that's the best explanation I've got.

 

"Bad" rear bearings can accelerate hub failure.  I started to get "snapping" sounds in the LR in sustained righthand sweepers, and the car's handling would alter as the snapping sound was being made.  Upon diassembly I found the hub looked "melty" where it pressed through the inner races.  Because the bearings were starting to "seize" the press fit was slipping, and that was the snapping I was hearing.

 

I've never seen a NEW hub fail in less than, say, 40 weekends.  Of course, wheel-to-wheel and wheel-to-wall activities can make anything happen.  My rule is, if the impact was hard enough to bend something in the back, you replace the bearing and hub.  Else, the hub and bearing seem to stand up fine to normal wheel-to-wheel hits and grinding.

 

IIRC, Watts failed one that had 80K miles and several seasons on it.  Many of us ran donor hubs for a few seasons and then started seeing failures.  Since the 1.6 hubs haven't been available for years, if you have small-knurl studs in the back (i.e. studs the same knurl diameter as front hubs), then you must have "original" hubs.  This winter would be a great time to change them

 

There are old threads in the archives on this failure, but I don't know how to find them, meaning I don't know if they are SpecMiata.Com or here.

 

I don't think heat applied to ease disassembly is a contributor - unless you are getting things cherry red.

 

I also haven't seen any drop in quality with hubs from Mazda over the years.

 

I've also never had a problem getting inner races off - like someone else said, a chisel, a bearing separator, and a press works every time.  A GOOD bearing separator forgoes the need for the chisel.

 

IF you are going to cut the inner race off with a cutoff wheel, stop short of cutting into the hub and then use the chisel in the slot you cut with the Dremel.  The inner race is hard and brittle, it will crack off if you cut it most of the way through.

 

There is a slight art to pressing rear hubs together.  If you "overpress" them and then torque the nut down on top of it, you're doing it wrong.  Press it together as little as possible to bottom everything, get it installed, put the nut on "snug" only, run it on the jackstands or around the block, and THEN torque to spec. 

 

I see a LOT of hackjobs on hubs I work on that have undergone previous rear bearing replacements - bearings pressed in "backwards" (not that it matters much for us), cutoff wheel gouges in the hubs, seals folded back into the bearing causing drag and grease puking out, cages damaged from "repacking", premature failures from "overpressing", etc.

[SaulSpeedwell]

I did not use heat to get the race off, I used heat to get the half shaft out of the hub.

 

If that was the hub i used heat on, then the failure was right where i used heat.

 

 

You can take the whole knuckle off with the halfshaft attached, and throw it in the deepfreeze if you have one.  Or hell, throw it in a snowbank.  This will help you more than heat. 

 

Heat makes the hub and axle swell, although by doing so it may be "breaking rust" - but so would whacking it with a hammer?   

 

Making it cold should make it come apart nicer.

[LarryKing]

R.G. prefers sobriety.

 

I had S.S. replace the bearings in my rear hubs recently. Apparently my local professional bearing shop whom I hired to do them previously committed several of the atrocities listed above. (backwards, gouged, etc...)