I've read a lot of opinions on whether these are any good and I just want to say NO!
I figured I was asking a lot from stock bearing with 130K+ miles to get me around autox tracks all summer so I went ahead and replaced them with new ones from AutoZone. The drivers side didn't even last one day!! I was getting a loud band from the front driver side only when the wheel was turn most of the way. I spent the last few days accusing the steering rack but today I decided to put the original bearing back in and the noise is gone.
So the hunt is on for a better hub..
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05:49 PM
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hookdonspeed Member
Posts: 7980 From: baltimore, md Registered: May 2008
Hard to say if a better hub will ever exist. The OEM GM hubs were very HD and had larger ball bearings. These aftermarkets will most likely always have smaller bearings in them. If I have mine made they may only be a bit better than the China bearings. Mine would have the best grade bearings inside them but still smaller bearings compared to the OEM GM units. For daily driver use they should be OK. Racing puts a terrible amount of stress on them. I doubt any company would ever be willing to make them like OEM units. If they would the price would be terribly high.
------------------ Rodney Dickman
Fiero Parts And Acc's Web Page: All new web page!:www.rodneydickman.com Rodney Dickman's Fiero accessories 7604 Treeview Drive Caledonia, WI 53108 Phone/Fax (262) 835-9575
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06:11 PM
Will Member
Posts: 14226 From: Where you least expect me Registered: Jun 2000
The packaging is the trick on the '88's. The "offset" depth from the hug mounting flange on the knuckle to the wheel mounting flange is the smallest of any GM bearing... ever, AFAIK.
When you have a package that small, the bearings have to be close together. This radically increases the forces applied to them from off-axis loads like cornering.
I haven't looked under my Formula recently, but IIRC there is *some* room between the back of the knuckle and the spring. A deep housing could be made that would move the inner bearing inboard by a couple of inches at least. That housing with a custom spindle and changing out the ball bearings for tapered rollers would dramatically increase the load capacity of the hub, but it would end up a fully custom unit with radically different packaging compromises than the original.
I think GM built some rear bearings for Berettas this way... but the "offset" of those units is greater than that of the '88 front hubs. If the mounting bolt pattern is the same, the hubs could be used by putting spacers between the caliper and mounting ears on the knuckle, but that would increase both scrub radius and steering effort noticeably. This could be counteracted by using higher offset wheels... everything is interlinked.
Just your typical dura-junk im suprized it didn't last you a day. New record in my book. While at work was able to see a timken part number but was showing not available. We can call the vendor and see if they might start making them again but chances are its not very likely.
Another (albeit one-time high cost) alternative is to use HT's knuckles which were designed to accept relatively inexpensive Fiero rear wheel bearing assemblies. For the front installation, a large bolt and nut are used to retain the bearing halves together as a substitute for the axle and hub nut which are required when used in the rear. The knuckles aren't cheap, but they solve the '88 front bearing dilemma, and are offered in several drop configs to boot.
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10:04 PM
Jun 4th, 2011
Raydar Member
Posts: 40727 From: Carrollton GA. Out in the... country. Registered: Oct 1999
Another (albeit one-time high cost) alternative is to use HT's knuckles which were designed to accept relatively inexpensive Fiero rear wheel bearing assemblies. For the front installation, a large bolt and nut are used to retain the bearing halves together as a substitute for the axle and hub nut which are required when used in the rear. The knuckles aren't cheap, but they solve the '88 front bearing dilemma, and are offered in several drop configs to boot.
I've seen them. Is anyone actually using them? Got any idea about how they hold up?
------------------ Raydar 88 4.9 Formula IMSA Fastback Read Nealz Nuze!Praise the Lowered!
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02:56 AM
Rodney Member
Posts: 4715 From: Caledonia, WI USA Registered: Feb 2000
Originally posted by MeAndMyFi: While at work was able to see a timken part number but was showing not available. We can call the vendor and see if they might start making them again but chances are its not very likely.
All OEM Pontiac Fiero 88 front wheel bearings were made by one company. That company is long since gone. All the 88 front wheel bearings that were sold in the years past at parts houses etc were all from this one company irregardless whose name was on the box.
------------------ Rodney Dickman
Fiero Parts And Acc's Web Page: All new web page!:www.rodneydickman.com Rodney Dickman's Fiero accessories 7604 Treeview Drive Caledonia, WI 53108 Phone/Fax (262) 835-9575
I just assumed that some else was making these hubs. I'm getting the impression from reading these responses that this is not true? This could be a real problem because this originals will not last forever.
I wanted to clarify the failure mode. The bearing has movement in the direction of the arrow. In-and-Out. There is no wiggle or other movement.
What was happening with the wheel turned all the way is the bearing would slide in/out with a bang. It sounds like some of you are very knowledgeable about these bearings so maybe this will help. If someone has another solution that WILL work then cost isn't really an issue (with in reason). These cost ~$155 for the pair. Doubling that doesn't seem unreasonable.
(edited price - found the receipt)
[This message has been edited by My1stMidEng (edited 06-04-2011).]
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07:38 AM
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hookdonspeed Member
Posts: 7980 From: baltimore, md Registered: May 2008
I wanted to clarify the failure mode. The bearing has movement in the direction of the arrow. In-and-Out. There is no wiggle or other movement.
What was happening with the wheel turned all the way is the bearing would slide in/out with a bang. It sounds like some of you are very knowledgeable about these bearings so maybe this will help. If someone has another solution that WILL work then cost isn't really an issue (with in reason). These cost ~$125 for the pair. Doubling that doesn't seem unreasonable.
im going to call the company we deal with on monday, they have that in as a good part #, going to see if they have any, and if not, what it would take to run a batch (probably require pre-orders?) but they make a quality bearing, even for being china (sadly whats not anymore?) they holdup to the federal moguls we sell at 1/2 the price....
[This message has been edited by hookdonspeed (edited 06-04-2011).]
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08:13 AM
Jun 6th, 2011
hookdonspeed Member
Posts: 7980 From: baltimore, md Registered: May 2008
I had a similar problem with the failure of a set of 86 bearings. The wheel would move in and out in the manner described in the picture. My question is what is in there? There should be no way for the bearing to do that especially after only one hard day of driving. I would expect the bearings to wear faster than OEM but not like that.
Someone needs to take one of these apart, there has to be a nut or something sandwiching the bearings and even so I do not understand how that could happen so fast.
How hard is it to move in and out? Is it easy or does it take some force?
Please take it apart!
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09:13 PM
Jun 7th, 2011
ManMadeChickens Member
Posts: 553 From: Clackamas, Oregon USA Registered: Jun 2006
I had a similar problem with the failure of a set of 86 bearings. The wheel would move in and out in the manner described in the picture. My question is what is in there? There should be no way for the bearing to do that especially after only one hard day of driving. I would expect the bearings to wear faster than OEM but not like that.
Someone needs to take one of these apart, there has to be a nut or something sandwiching the bearings and even so I do not understand how that could happen so fast.
How hard is it to move in and out? Is it easy or does it take some force?
Please take it apart!
The pre-88 bearings are totally different bearings, they use a spindle with removable and replaceable bearings. The 88 bearings are one unit, with the bearings being non-serviceable.
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07:58 PM
fieroguru Member
Posts: 12128 From: Champaign, IL Registered: Aug 2003
I would have popped the rear cap off to see if the flange shaft is retained by the stock style magnetic C-clip or the threaded nut. If it has a nut, then you could have just tightened it up a notch. If it had the magnetic C-clips then you might have been able to install a shim between the inboard inner race and the C-clips. Here is what a front 88 wheel bearing looks like disassembled. From Left to right: Stamp steel retainer for the C-Clips, C-Clips, Inboard inner race, inner bearing, outer bearing, and the seal. The outer races are machined into the 88 housing itself and the outboard inner race is machined into the inner shafts, so they are not rebuildable since the housing and wheel flange shaft wears with the bearings.
Here is an 88 front flange shaft (left) compared to the fiero rear flange shaft:
For those with access to machining equipment, Bubbajoe modified some 88 front bearing housings to accept the flange shaft from the rear bearing on the 79-85 longitudinal FWD cars. This gives you the 4 3/4" pattern, but once you do the modification the front wheel bearings have tapered bearings with removable inner and outer races, so they are rebuildable going forward.
quote
Originally posted by bubbajoexxx:
no more plastic caged ball bearings full tapered roller bearings and races when i disassembled the stock fiero units they came with plastic cage ball bearings and the cages showed signs of melting from lack of grease this new setup eliminates the plastic parts and give true roller bearings and a 1 1/8 stub shaft and 5X4 3/4 bolt circle
a couple of pics showing the shaft size change and new bearing
as seen in the pics the bearing is now a presision roller bearing insted of a cheep plastic low quality ball bearing
I know this isn't a big-running item but it is needed. I would love to see a new front hub like above that could hold up to all kinds of abuse.
In order to compete with my fellow racers I've had to go with wider tires. And the only way to get wider tires in the front was to add a spacer. Yes, I'm expecting front hub failures from the extra stress but this is why I initially replace my front hubs. Now that DuraLast didn't last I'm worried. (am I ending all my posts in 'I'm worried'!?!)
[This message has been edited by My1stMidEng (edited 06-08-2011).]
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05:35 AM
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Will Member
Posts: 14226 From: Where you least expect me Registered: Jun 2000
In order to compete with my fellow racers I've had to go with wider tires. And the only way to get wider tires in the front was to add a spacer. Yes, I'm expecting front hub failures from the extra stress but this is why I initially replace my front hubs. Now that DuraLast didn't last I'm worried. (am I ending all my posts in 'I'm worried'!?!)
You could probably use rear hubs (with a large bolt through them) on your front, without spacers, in your case. The rear hubs stick out farther, so depending on the size of your spacer, it may not be needed.
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01:53 PM
thedrue Member
Posts: 1104 From: Vancouver, WA USA Registered: Feb 2009
I know the 88 fronts are different than the earlier tapered rollers but there has to be something holding it all together, weather a nut or otherwise. I am just saying I do not understand how there can be that much play in that direction after such short use. It just does not make sense.
I would like to see inside those bearings so we can see exactly what is going on. There are definitely space constraints but I do not know why this part is sooooo hard to get right.
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03:28 PM
Marvin McInnis Member
Posts: 11599 From: ~ Kansas City, USA Registered: Apr 2002
I would like to see inside those bearings so we can see exactly what is going on. There are definitely space constraints but I do not know why this part is sooooo hard to get right.
You don't realize just how significant those "space constraints" can be. The load on an assembly (e.g. a bearing) is roughly proportional to the cube of a structure's linear dimensions. Extending the space between the two bearings in an '88 Fiero front hub as little as 1/2 inch would reduce bearing loads dramatically. Increasing the bearing diameter would not only decrease bearing loads, but the larger housing would be much stiffer and stronger.
You might find the discussion in this thread enlightening, from someone who knows what he's talking about: https://www.fiero.nl/forum/F...HTML/108566.html#p34. I recommend that you read the entire thread.
Also consider that the Fiero hubs were designed for the loads produced by 1980s tire and suspension technology, in normal street use. Even OEM-sized street tires today are stickier than most street-legal "performance" tires were back in 1988.
[This message has been edited by Marvin McInnis (edited 06-08-2011).]
You could probably use rear hubs (with a large bolt through them) on your front, without spacers, in your case. The rear hubs stick out farther, so depending on the size of your spacer, it may not be needed.
Has this been Done? Is there a thread on this?
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07:52 PM
fieroguru Member
Posts: 12128 From: Champaign, IL Registered: Aug 2003
Yes. Held/RCC used them for their suspension kits with their custom uprights, and Nashco installed rear bearings in the stock front uprights for his 88 AWD Electric/Gas hybrid. This thread has a link to his blog with the info, or just PM him. The bore needs to be enlarged on the 88 front upright and the bolt patterns are different, to you need to elongate the holes on the bearing flange. https://www.fiero.nl/forum/Forum2/HTML/100835.html
You don't realize just how significant those "space constraints" can be. The load on an assembly (e.g. a bearing) is roughly proportional to the cube of a structure's linear dimensions. Extending the space between the two bearings in an '88 Fiero front hub as little as 1/2 inch would reduce bearing loads dramatically. Increasing the bearing diameter would not only decrease bearing loads, but the larger housing would be much stiffer and stronger.
You might find the discussion in this thread enlightening, from someone who knows what he's talking about: https://www.fiero.nl/forum/F...HTML/108566.html#p34. I recommend that you read the entire thread.
Also consider that the Fiero hubs were designed for the loads produced by 1980s tire and suspension technology, in normal street use. Even OEM-sized street tires today are stickier than most street-legal "performance" tires were back in 1988.
I just read the post frmo eBearing and I'm worried (damn, i said it agian). So even if I get the hubs replaced (it seems eBearing is making hubs again!? need to check) then something else will fail. What have I gotten into!
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08:05 PM
Jun 9th, 2011
Will Member
Posts: 14226 From: Where you least expect me Registered: Jun 2000
no more plastic caged ball bearings full tapered roller bearings and races when i disassembled the stock fiero units they came with plastic cage ball bearings and the cages showed signs of melting from lack of grease this new setup eliminates the plastic parts and give true roller bearings and a 1 1/8 stub shaft and 5X4 3/4 bolt circle
as seen in the pics the bearing is now a presision roller bearing insted of a cheep plastic low quality ball bearing
Every forum on the web can nest quotes EXCEPT THIS ONE.
What thread is this from?
I'd like to see more of that modified hub... *BUT* one of the advantages of making the outer bearing inner race integral to the sprindle is that the internal radius is "built in". That's much harder to do with the tapered roller setup. I'm curious about how that setup would work in racing use (IE with enormous slicks).
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03:40 PM
fieroguru Member
Posts: 12128 From: Champaign, IL Registered: Aug 2003
I'd like to see more of that modified hub... I'm curious about how that setup would work in racing use (IE with enormous slicks).
I'd like to see more detail, too. My speculation, based on nothing more than accumulated engineering intuition, is that the modified housing will become the new primary failure point. I suspect that stresses will concentrate in the area where the old machined outer races are removed to accept the new roller bearing outer races, and the original race hardening won't help with fatigue resistance either. That doesn't necessarily mean that the modified bearings still won't perform better than the OEM front hub cartridges.
[This message has been edited by Marvin McInnis (edited 06-09-2011).]
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06:01 PM
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Jun 10th, 2011
Will Member
Posts: 14226 From: Where you least expect me Registered: Jun 2000
I'd like to see more detail, too. My speculation, based on nothing more than accumulated engineering intuition, is that the modified housing will become the new primary failure point. I suspect that stresses will concentrate in the area where the old machined outer races are removed to accept the new roller bearing outer races, and the original race hardening won't help with fatigue resistance either. That doesn't necessarily mean that the modified bearings still won't perform better than the OEM front hub cartridges.
3. Today I picked up the hub bearing assemblies to use in the 88 front suspension swap. These units will be modded to fit the 1988 Fiero spindles and will also accept the Corvette rotors and bolt pattern. They are AC Delco Hub Bearings from an 85 S10 4X4 - Special thanks to Bubbajoe who is engineering this custom mod.
Stock 88 units are disassembled to get the mounting plate for transfer to the new unit. Notice how much larger and stronger the centre shaft will be once the conversion is complete:
no more plastic caged ball bearings full tapered roller bearings and races when i disassembled the stock fiero units they came with plastic cage ball bearings and the cages showed signs of melting from lack of grease this new setup eliminates the plastic parts and give true roller bearings and a 1 1/8 stub shaft and 5X4 3/4 bolt circle
a couple of pics showing the shaft size change and new bearing
as seen in the pics the bearing is now a presision roller bearing insted of a cheep plastic low quality ball bearing
I stopped by Joe's and gave him the spindles. He graciously offered to fab up the caliper adapter brackets now that the hub bearing units are complete.
[This message has been edited by Will (edited 06-10-2011).]
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08:35 AM
Will Member
Posts: 14226 From: Where you least expect me Registered: Jun 2000
From the pics Fieroguru initially posted in this thread, it looked like the flange and spindle had been modified to accept the roller bearings. On further research, it looks like the Caddy bearings start off as rollers an the spindle hasn't been touched (except maybe to lengthen the threads for the preload nut) and all that was done was to modify the '88 housing to accept the roller bearings.
I think a better way would be to make a custom housing that would keep all the internal parts in the Cadillac hub in their original positions, while on the outside it has the correct offset and bolt pattern to bolt to the '88 knuckle.
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08:44 AM
Marvin McInnis Member
Posts: 11599 From: ~ Kansas City, USA Registered: Apr 2002
I think a better way would be to make a custom housing that would keep all the internal parts in the Cadillac hub in their original positions, while on the outside it has the correct offset and bolt pattern to bolt to the '88 knuckle.
Thanks for consolidating the information. I had seen it all, but for reference it's nice to have it all in one place.
I agree that a custom housing would be the way to go, but that would involve a custom forging and/or some rather sophisticated CNC milling ... way beyond the capabilities of most small machine shops. It's still worth considering, though.
Another approach would be to create a CAD rendering, print a prototype model on a 3-D printer, and then investment cast it in steel. Strength and fatigue resistance would be a concern with this approach, as with most castings, but you might be able to use FEA to optimize the new housing structurally within the material and external size constraints. I have all the prototyping resources available, as well as people who are highly competent using them, and it's an interesting idea that I'll have to think about.
If you have any other ideas along these lines, please let me know.
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10:27 AM
Will Member
Posts: 14226 From: Where you least expect me Registered: Jun 2000
Originally posted by Marvin McInnis: I agree that a custom housing would be the way to go, but that would involve a custom forging and/or some rather sophisticated CNC milling ... way beyond the capabilities of most small machine shops. It's still worth considering, though.
LOL... you can turn it on a lathe from 4 (or maybe 5) inch round bar. The only thing you need to mill is the three bolt pattern attaching it to the knuckle, and that can even be done on a MANUAL mill. The flange can stay round... it doesn't have to be triangular. FEA is completely unecessary in this application, because if you fill every cubic millimeter you can with steel, it will be as strong as it can be, yet only a few grams heavier than a fully optimized version. The packaging constraints are *THAT* tight.
Will, Marvin, thanks for all the info. Your expertise is way beyond my knowledge but I'm trying to hang in there. I'm also hoping this all becomes a real product.
BTY - I sent eBearing email asking about his and I haven't got a reply.
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05:52 PM
Xanth Member
Posts: 6886 From: Massachusetts Registered: May 2006
Will, Marvin, thanks for all the info. Your expertise is way beyond my knowledge but I'm trying to hang in there. I'm also hoping this all becomes a real product.
BTY - I sent eBearing email asking about his and I haven't got a reply.
eBearing, or at least someone using the name, actually responded in this thread here:
LOL... you can turn it on a lathe from 4 (or maybe 5) inch round bar. The only thing you need to mill is the three bolt pattern attaching it to the knuckle, and that can even be done on a MANUAL mill. The flange can stay round... it doesn't have to be triangular.
You may be right. I'm thinking of it from an "optimum design" and "zero defects" perspective, I'm not a machinist, and I haven't modeled the housing in detail. I do think that doing the mounting flange properly, for example, so that it only contacts the knuckle at the attach pads, is likely to be more difficult than you portray. Any part machined from a steel billet is going to be weaker than an equivalent forging, and a casting will usually be weaker still. That said, machining from billet is still probably a best method for prototyping or small-volume production if it's "strong and fatigue-resistant enough."
quote
FEA is completely unecessary in this application, because if you fill every cubic millimeter you can with steel, it will be as strong as it can be, yet only a few grams heavier than a fully optimized version. The packaging constraints are *THAT* tight.
You are familiar with the concept that filling "every cubic millimeter" with material can sometimes weaken a structure rather than strengthening it, aren't you? This is especially true when external constraints are tight. Too much material in the wrong places can lead to stress concentrations that become primary points of accelerated failure. Again, I'm thinking in terms fo "doing it right" (if possible), and that involves every aspect of the housing design .... right down to doing individual stress calculations on each of the three attachment bolts.
Of course, I may be fooling myself, thinking that we accurately know what the actual service loads are going to be. Still, a balanced design will perform at least as well (and usually better) than an ad-hoc design. I'm an engineer, not a blacksmith.
[This message has been edited by Marvin McInnis (edited 06-11-2011).]
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11:50 AM
Will Member
Posts: 14226 From: Where you least expect me Registered: Jun 2000
I do think that doing the mounting flange properly, for example, so that it only contacts the knuckle at the attach pads, is likely to be more difficult than you portray.
Why would you want to do that? *IF* you do that, you destroy the symmetry of revolution in the flange. People with too much computing power at their fingertips forget what makes analysis easy and heuristics work...
quote
Originally posted by Marvin McInnis: Any part machined from a steel billet is going to be weaker than an equivalent forging,
That's a pretty idealized point of view. The product of any sort of rolling mill is going to be FAR more consistent than forgings, from one part to the next.
quote
Originally posted by Marvin McInnis: You are familiar with the concept that filling "every cubic millimeter" with material can sometimes weaken a structure rather than strengthening it, aren't you? This is especially true when external constraints are tight. Too much material in the wrong places can lead to stress concentrations that become primary points of accelerated failure. Again, I'm thinking in terms fo "doing it right" (if possible), and that involves every aspect of the housing design .... right down to doing individual stress calculations on each of the three attachment bolts.
That's why we machine radii instead of sharp corners. I'm just saying that design rules of thumb are there to get close enough in applications that aren't critical enough to require FEA. The degree of optimization that may be attainable won't necessarily be worth the effort.
[This message has been edited by Will (edited 06-11-2011).]
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05:31 PM
Dec 14th, 2011
sspeedstreet Member
Posts: 2306 From: Santa Maria, CA Registered: Dec 2002
