I developed a bespoke design for shells to replace the stock rubber Fiero front lower control arm bushings with spherical bearings. The bushings are the same across all years of Fiero production, and thus the shells fit all years as well.
I started looking at getting 8 shells (two vehicle sets) made. That quote runs just under $100 each shell for quantity of 8.
The CNC program development and machine setup are fully half the cost of the quote, so if I could run more parts, the price per part will come down significantly. A run of 20 (3 additional sets) will be $51 each; a run of 52 parts (11 additional sets) will be $42 each
In addition to four shells, a full kit will require two spacers per shell, one spherical bearing per shell, one ID snap ring per shell and, for '88s only, two shaft seals per shell. Each kit will need one of my installation/removal tools as well.
One kit will include: 4x Shells 8x Spacers 4x Bearings 4x Snap rings 1x Installation/Removal tool 8x Seals for '88's
Since the group buy is to bring down the cost of the shells, the number of buyers does not have to be for a single type of kit. Two '84-'87 buyers and 1 '88 buyer are still 3 buyers and kits will be priced accordingly. The kit price will interpolate more or less linearly for number of kits between 3 and 11.
The shells fit ALL years of Fiero front lower control arms. They WELD in place. The difference between '84-'87 kits and '88 kits are only the shaft seals.
Why spherical bearings?
OEMs use rubbber bushings because they are CHEAP. As the suspension gets further from static ride height, the "wind up" of twisting the rubber bushings becomes a second spring. Under high loads in hard corners, rubber bushings deflect. Bushing deflection in a hard corner reduces camber and prevents the chassis from making the best possible use of the tires. In a car with very short knuckles, such as a Fiero, a modest amount of bushing deflection becomes a large amount of camber loss. This reduces ultimate grip and unpredictable deflection makes the "ragged edge" more ragged. The car is inconsistent at the limit and can be upset by bumps that change any tire's camber in mid-corner.
Making these problems worse is the fact that modern performance tires are very much stickier than '80's performance tires... to the point that modern performance tires are almost what race tires were in the '80's. Greater grip available with modern tires makes the problems with OE rubber that much more obvious.
There are alternatives to OE rubber. Polyurethane is by far the most common, with Delrin or UHMW available for rare applications. Urethane is a "sticky" plastic which requires frequent greasing and can add significant stiction and preload torque to a suspension pivot. Urethane is actually a poor material choice for bushings. Aftermarket manufacturers use urethane because it's cheap and easy to mold. Delrin and UHMW are "slippery" plastics and have less frictional torque, but are also very rare and typically custom made. They are rare because they have to be machined--a fundamentally more expensive process--rather than molded like urethane. There is also significant engineering involved in designing Delrin or UHMW bushings in order to minimize pre-load and maximize bushing life. Both are plastics with hardness measured on the Shore durometer scale, which makes them still fairly soft materials.
Spherical bearings are free moving with very little preload torque. When installed in my shells, these bearings have a typical preload of 20-40 inch-lbs, with a few getting as high as 60 inch-lbs. Spherical bearings have essentially zero deflection, as you would expect from materials measured by Rockwell--as opposed to Shore--hardness.
Installing spherical bearings will make your car's ragged edge significantly less ragged. Spherical bearings will improve your car's "path accuracy" and your ability to place the car wherever you want on the line through any given corner. Consistent camber behavior will produce consistent grip from your tires, allowing you to push the car harder with more confidence.
For the '84-'87 Fiero specifically, in each front lower control arm, the forward and rear pivots are neither parallel nor coaxial. This means that there is a large amount of "off axis" motion in each pivot. This is not a problem for a rubber bushing or a spherical bearing, but IS a problem for polyurethane, resulting in excess stiction and binding above and beyond what would otherwise result from simply using urethane. This off axis motion does not bother spherical bearings in the slightest. However, it DOES cause problems with any seals used with the spherical bearing, as the spacer ends up off center in the shell, which is bad for a seal. That is why I will only send seals with kits for '88 cars. The 1988 Fiero suspension design uses more conventional A-arms with coaxial pivots and thus can have seals.
Spherical bearings will increase NVH *slightly*. I have not driven a Fiero with spherical bearing front pivots yet (thats why I'm having these shells made...), but I have driven my Formula with spherical bearing rear lateral link pivots for years; I did not notice *ANY* change in NVH when I installed those.
How to install:
1. Remove control arm from car 2. Remove current bushings AND SHELLS from control arm 3. Install spherical bearings to spherical bearing shells using installation tool and bench vise. 4. Slip spherical bearing shells into control arm 5. Install control arms to chassis with spherical bearing spacers installed in spherical bearings. Snug the control arm pivot bolts. There is no need to apply full bolt torque at this time. 6. Tack weld spherical bearing shells into control arms 7. Remove control arms from chassis 8. Remove spherical bearings from shells without breaking tack welds 9. Completely weld shells into control arms. I *STRONGLY* recommend TIG welding. Take the control arm to a welding shop if you are not 100% confident in your skills. 10. Reinstall bearings, install seals as required, install spacers 11. Install control arms to chassis, bring bolts to full torque (60 ftlbs for 12mm class 10.9; 80ftlbs for 12mm class 12.9) 12. Reassemble suspension 13. Drive the hell out of it!
Installed:
Welding as shown below does not distort the bore. I measured preload before and after welding and it only changed by +/-2 lnlbs across the 4 units. Pictured are of shells of a very similar design installed in a pair of REAR arms that I used for proof of concept for spherical bearing shells on The Mule, my 1987 GT Northstar car.
Things you should know:
The '88 crossmember has mounting ears that make +/-0.030 overall length tolerance still installable. The '84-'87 front end has the rear pivots welded to the body, but the forward pivots on the crossmember. This means that the crossmember bolts can be loosened to shift the crossmember to accommodate overall length tolerance mis-matches. These facts mean that the front control arm shells could probably be tacked in one crossmember or chassis, then installed into a different crossmember or chassis with minimal problems.
Buyers:
You have an order when I have a $100 deposit from you. PM for payment info. Full payment will be due prior to shipment. Buyer will pay actual shipping costs. I will mark buyers as paid as they provide a deposit.
Fascinating Will, especially since I'm in the middle of refurbishing my '88 fronts with poly.
I have been thinking of making my own upper/lower arms with spherical housing cups, I'd never considered fitting them to the standard arms.
Soooo, questions:
Would you consider selling just the shells and spacers? Being in Scotland, it would cut down my carriage cost considerably. I know my way round sphericals, sourcing and fitting is not a problem. ;-) sorry, couldn't resist.
Is the shell parallel, not tapered/stepped like the annoying standard ones? Only reason I can think it needs aligned before welding, unless I'm being thick as usual and missing something.
Is the spacer a reducer spacer, running as big a spherical as possible?
Fascinating Will, especially since I'm in the middle of refurbishing my '88 fronts with poly.
I have been thinking of making my own upper/lower arms with spherical housing cups, I'd never considered fitting them to the standard arms.
Soooo, questions:
Would you consider selling just the shells and spacers? Being in Scotland, it would cut down my carriage cost considerably. I know my way round sphericals, sourcing and fitting is not a problem. ;-) sorry, couldn't resist.
Is the shell parallel, not tapered/stepped like the annoying standard ones? Only reason I can think it needs aligned before welding, unless I'm being thick as usual and missing something.
Is the spacer a reducer spacer, running as big a spherical as possible?
Regards, iain
Thanks for responding!
If you were about to install polyurethane, I posted this just in time for you, then!
The bearings for which I designed the shells are are Aurora COM-10T units. Any 5/8" spherical bearing should fit, but the preload torque may be more or less for other parts. I would have loved to run a -12 part, but I did not think I'd have enough wall thickness left in the shell after adding the ID snap ring groove. I can send you a "basic" kit with just the shells and spacers and a BOM for the rest... but the shells and spacers are the majority of the weight in a kit with a weight ~5 lbs, so you won't save much on shipping.
I'm not sure what you mean by "tapered/stepped like the annoying ones". My parts are not annoying at all, just me When installing a bearing into a shell, you'd use my installation tool and bench vice to seat the bearing against the integral shoulder inside the shell. With the bearing fully seated against that shoulder, the snap ring can be installed to make sure the bearing does not unintentionally come out.
The outside diameter of the shell is stepped so that the shells are a close slip fit in the holes in the control arms. Tack welding in place is more about making sure that the axial distance between the shells matches the crossmember the control arm will be installed to. This allows the control arm to be installed and reinstalled to the crossmember smoothly and easily. The slip fit between the shells and control arms is snug enough that there's no real angular variation possible.
The spacers are stepped so that they can both clamp the bearing and center it on the 12mm bolts in the suspension pivots. They're also exactly the right length to duplicate the installed length of the original bushings, again contributing to easy installation and R&R.
Here are some other photos of the rear arms following powder coating and assembly:
------------------ "I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."
I like it. I would buy in by September, but the car budget suffers this summer.
Sooo... there's going to be some time for the group buy to run to accumulate buyers, then there's going to be production time once I place the order with the machine shop... If you can make the deposit now/soon I can just box yours up and hang onto it. You can pay when you're ready and I'll ship it then. At this point, delivery dates are going to run into September anyway.
[This message has been edited by Will (edited 08-02-2020).]
The shells are stepped a little because the original bushings are stepped and the holes in each side of each control arm location are slightly different sizes. The large OD is 1.590"
I wasn't thinking about your Held suspension when I mentioned the idea.
Edit: If you need the OD smaller--which I guess you do since the Held arms were made to take Fiero urethane bushings directly--we can figure something out relative to turning the OD down to fit your control arms. The shells are relatively thick.
[This message has been edited by Will (edited 08-06-2020).]
I'm thinking end of September; I'll let the group guy run through the end of August, then place the order at the beginning of September. It's a simple order for this shop so it should only take a couple of weeks to produce.
Do you mean your IMSA '84? Do you have a build thread for that car?
Is your 2.0 an LT3? Are you running a Getrag trans? Spherical bearings in the front suspension would work out great in that car as well Although I totally get that buying two kits would be spendy... after all, that's what prompted me to create this group buy!
I'm thinking end of September; I'll let the group guy run through the end of August, then place the order at the beginning of September. It's a simple order for this shop so it should only take a couple of weeks to produce.
Do you mean your IMSA '84? Do you have a build thread for that car?
Is your 2.0 an LT3? Are you running a Getrag trans? Spherical bearings in the front suspension would work out great in that car as well Although I totally get that buying two kits would be spendy... after all, that's what prompted me to create this group buy!
Yeah these would go in the 84 IMSA. I don’t have a build thread that’s in depth and have been somewhat posting regular video updates on my YouTube channel. I’ve driven it daily this summer, only had the 88 with the 2.0 LT3 out twice this year, yes it has a getrag. I want to get the IMSA set up for some autocross events/track days. I don’t have a ton of money into it like I do the 88 so I wouldn’t be too upset if something happened. Plus 3800s aren’t hard to find if I blow it up. 🤣 the rear suspension has coil overs and poly bushings in the lower control arms and new struts. I need to address bushings in the front suspension due to age. These would be perfect. Would do poly in the upper arms.
[This message has been edited by FieroMaster88 (edited 08-07-2020).]
Yeah these would go in the 84 IMSA. I don’t have a build thread that’s in depth and have been somewhat posting regular video updates on my YouTube channel. I’ve driven it daily this summer, only had the 88 with the 2.0 LT3 out twice this year, yes it has a getrag. I want to get the IMSA set up for some autocross events/track days. I don’t have a ton of money into it like I do the 88 so I wouldn’t be too upset if something happened. Plus 3800s aren’t hard to find if I blow it up. 🤣 the rear suspension has coil overs and poly bushings in the lower control arms and new struts. I need to address bushings in the front suspension due to age. These would be perfect. Would do poly in the upper arms.
As noted above, I've prototyped and installed shells for the '84-'87 rear control arms, although I haven't been able to put many miles on them yet... depending on the success of this group buy, I may do one for those units. If I do, I'll make sure you know about it!
Sure you don't want a set for your '88 as well?
//
The Family II engines are interesting ducks, but not super common in the US. I've heard of a couple of Fieros with those swaps. Never heard anything bad; they're just rare. I bet finding the Getrag with that bellhousing was fun!
Based on a pmbrunelle's suggestion, I had spacers quoted in 303 stainless, since they'll be exposed to weather in all cases. Stainless spacers are only $1.50/part more than the 12L14 spacers I'd originally quoted; that's only $12/kit increase. I assume that doesn't break anyone's bank.
First batch of Fiero Front Lower Control Arm Spherical Bearing Shells:
Removing the old bushings was actually kind of difficult
I'm using one of the spherical bearings shells (destined for my car; that's not a customer part) and a random piece of tubing as press mandrels. Yes, this raised a burr on both the shell an the control arm, which I then had to clean up with a file before they'd go back together. No big... they're going to be welded and painted. The part in the middle supporting the ears of the control arm is a 2" conduit clamp that I narrowed to 1.210 using a belt sander. That's the perfect width for working with the '88 front lower control arms.
Some fairly surgical media blasting to clean up the control arms for welding:
Shells slipped into the control arm in prep for installation to the crossmember in order to be tack-welded in place. The shells are a slip fit in the control arms. Making them a press fit would result in not having a good way to control the axial separation distance. A mismatch between the separation of the shells and the separation of the pivots on the crossmember or cradle would put an axial load on the bearings and probably reduce their service life.
Ooops... I don't think I grabbed a photo of the arm bolted into the body pre-welding.
I was not able to get a photo of the control arms tacked. I'll get a photo of them hanging in place in the position in which they were tacked next weekend.
Control arms welded:
This one actually shows something you're best off avoiding: melting/burning through the edge of the shell to the ID of the seal bore. Ooopsie.
I'd love to Will, I really would, but I've changed direction too many times on this car already, I'm desperate to get it rolling next year.
Keep it in mind and tell your friends about it! I don't know how soon we'll accumulate 5 more buyers. Maybe by then you'll be ready to step up a level.
My experience/process installing the spherical bearing kit,
First step is to remove the rubber, I find "burning" the rubber out is the easiest and fastest way, you don't actually burn anything, take a torch(a heat gun may work, I used a torch) and heat the outside of the shell, do this in a fairly uniform manner, all the way around. as you heat it, the rubber inside will begin to sizzle a bit, at this point, get a dowel or other implement that you can hit with a hammer, put it on the rubber, and give it a few swift hits, the bushing will pop right out, and you can move on to the next one. I did all 8 of of the bushings in the front control arms in about 30 minutes. when the rubber pushes out, it will smoke a bit, and leave a little bit of gooey residue, nothing too crazy hard to deal with. unfortunately, I don't have any pictures of that process. Â again, heat the metal shell, not the rubber directly.
Because I don't have a press (man I want one...) I needed an alternative way to remove the shells, this method can be accomplished by just about anyone, and requires very little finesse like may be required with a press to prevent distortion of the control arm.
Step one, cut into the flanged end, all the way to the arm, but not into it. ideally, this cut will be tangent to the ID of the shell, if the cut is radial to the shell, it might make things slightly more difficult, or increase the possibility of damaging the shell bore. additionally, it would be advised to make this cut at towards the bottom side of the arm, this will aid in the removal of the shell in the later steps. pretty much the opposite of what my picture shows (sorry, I suck sometimes...)
step two, put your hacksaw blade inside the shell and attach it to the frame like normal.
Step three start cutting the shell inline with the cut you made with the flange. the cut needs to be deep, but not all the way through, you don't want to cut the actual control arm.Â
Step four get a large cold chisel, and a hammer. Position the chisel over the cut you made on the inside of the shell, and give it a good hit or two the position of the cuts you made with your hacksaw will make or break this step, if you made your cut on the upper closed portion of the control arm you won't be able to put the chisel on the cut.
doing it this was folds the shell in on itself, the relief cut on the inside is critical, if you don't do the relief cut, you'll likely egg the bore the shell fits into, or damage the control arm, same for cutting the flanged portion of the shell at a tangent angle to the ID, if the cut is radial, the ends of the cut butt together and prevent the shell from folding. Â at this point, a few soft taps and the shell falls out of the LCA.
the results:
Next, thoroughly clean the control arms, you'll be welding the shells in place, the quality of your weld will hurt quite a bit if you don't clean the ends of the control arm thoroughly. while these could be MIG welded, I would recommend TIG welding them, there's not a lot of room to work, and it would be very easy to accidently end up putting weld inside the shell, which you really don't want. Alternatively, if you don't have a TIG, or don't feel comfortable welding the shells with it, you could tack the shells in place, and then take them to a local shop for finish welding. Personally, I would not even try and MIG weld these. Additionally, I would recommend fitting up the shells, tacking them, with 2 tacks, doing a quick, on the car test fit, tacking 2-4 more good tacks, test fitting, then finish welding, this way, if they're off in some way, it's easier to fix.
The shells are installed into the control arms, it's a pretty straightforward process, they only go in one way.
Next, I performed eight tacks per bearing. I did 12 and 6 on one side, then 3 and 9 on the other, then 9 and 3 on the first side, followed by 6 and 12 on the opposite. I didn't follow my own tack/fitup/tack advice, I'll cross that bridge later if there's a problem, I'm not quite to the point of installing them in the car at the time of typing this.
once both sides were four corner tacked, I came back and welded them in quarters, and in the same manner as the tacks.
They aren't my best welds, but they're also far from my worst, they should hold just fine.
spherical bearings(center) between the two spacers (left and right)
the bearing is a light press fit into the shell, a machined tool was included to press the bearing in with, there are a few ways to press the bearing in, the easiest method I have seen is to put the bearing in the shell, the install tool on the bearing, and then putting them between the jaws of a vise and tightening the vice. I don't have a good bench vise at the moment, so I used a large C clamp, and a block of wood. I highly recommend using a vise. also, a light coat of oil on both parts make installation go a bit smoother.
you could also use a hydraulic press, but you risk damaging the bearing or the control arm, they put out way more force than a vise.
the bearing will sit inside the shell and be retained by a snap ring on the back side. note the bearing is not yet pressed in.Â
here's the bearing pressed in, snap ring in place
also, if you're looking for something to keep the paint out of the shell/off of the bearing while you shoot it on the control arms, look no further than the UCA bushings... there's probably a more legitimate way to mask this off, maybe masking tape(what's that stuff for anyways???) but this worked fine for me.
I'm working on some other front suspension modifications, once they're done, I'll get these fully installed on the car.
TL: DR
these are pretty easy to install, take your time, and they go together nice and easy. I'll post a final review once I have the arms installed on the car, and I drive with them, so far, I'm impressed.
------------------ "I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."
I'm getting started on Group Buy #2. Based on feedback from recipients of the first batch, I have made some updates to the design. Functionality remains the same, but some details of the parts have been improved/corrected for easier installation and use.
Pricing should be similar, and I will be getting updated quotes for the revised parts this week or next. Payment terms remain the same: $100 deposit gets you a place on the list.
Members who have expressed interest in a buy via this thread or PMs: Iain FieroWannaBe darkhorizon FieroMaster88 Trace26 Wichita ragoldsmith TheseusRises ricreatr lafiera
[This message has been edited by Will (edited 05-22-2024).]
When installing a bearing into a shell, you'd use my installation tool and bench vice to seat the bearing against the integral shoulder inside the shell. With the bearing fully seated against that shoulder, the snap ring can be installed to make sure the bearing does not unintentionally come out.
