DIY Rear Camber Bolt/Knuckle Bushing
09-03-11, 07:20 PM
#31
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Replacement bushing
I ordered the rear knuckle bushings from the source in England, and they were terrible - noisy (polyurethane squeaked endlessly) and they were improperly shaped, permitting the rear end to move around and my alignment to change. To the source's credit (Martin) he provided a full refund when I sent the bushings back.
Since I'm in the auto suspension industry, I designed new bushings myself, reviewed them with my engineering team, and had high-quality samples made, which have worked fantastically since I put them in 6000 miles ago. The installation is pretty easy, once you've pressed out the old pillow bushings. The new ones slide into the knuckle and are dumbbell shaped (on one end), so they can't go too far. The other end has a doughnut that completes the dumbbell shape and you just bolt the bushing back into place with the original pillow bushing (and alignment) bolt. We installed two bushings in 25 minutes.
I figured that other people could benefit from avoiding the $1500 purchase of the knuckle, bushing and install, so I'll get quotes for a production run of 100 bushings and offer them for sale. I'm guessing that they'll come in under $200 for the pair, including bushing grease. With any luck, they'll be way under that figure, but I won't know until I get an RFP response.
Let me know if you are interested and I'll have these produced and offer a warranty and a guarantee on them so you have some confidence in their appropriate performance and reliability.
Best,
David Diamond
781-771-3636
davidbdiamond@verizon.net
Since I'm in the auto suspension industry, I designed new bushings myself, reviewed them with my engineering team, and had high-quality samples made, which have worked fantastically since I put them in 6000 miles ago. The installation is pretty easy, once you've pressed out the old pillow bushings. The new ones slide into the knuckle and are dumbbell shaped (on one end), so they can't go too far. The other end has a doughnut that completes the dumbbell shape and you just bolt the bushing back into place with the original pillow bushing (and alignment) bolt. We installed two bushings in 25 minutes.
I figured that other people could benefit from avoiding the $1500 purchase of the knuckle, bushing and install, so I'll get quotes for a production run of 100 bushings and offer them for sale. I'm guessing that they'll come in under $200 for the pair, including bushing grease. With any luck, they'll be way under that figure, but I won't know until I get an RFP response.
Let me know if you are interested and I'll have these produced and offer a warranty and a guarantee on them so you have some confidence in their appropriate performance and reliability.
Best,
David Diamond
781-771-3636
davidbdiamond@verizon.net
09-04-11, 08:58 AM
#32
I ordered the rear knuckle bushings from the source in England, and they were terrible - noisy (polyurethane squeaked endlessly) and they were improperly shaped, permitting the rear end to move around and my alignment to change. To the source's credit (Martin) he provided a full refund when I sent the bushings back.
Since I'm in the auto suspension industry, I designed new bushings myself, reviewed them with my engineering team, and had high-quality samples made, which have worked fantastically since I put them in 6000 miles ago. The installation is pretty easy, once you've pressed out the old pillow bushings. The new ones slide into the knuckle and are dumbbell shaped (on one end), so they can't go too far. The other end has a doughnut that completes the dumbbell shape and you just bolt the bushing back into place with the original pillow bushing (and alignment) bolt. We installed two bushings in 25 minutes.
I figured that other people could benefit from avoiding the $1500 purchase of the knuckle, bushing and install, so I'll get quotes for a production run of 100 bushings and offer them for sale. I'm guessing that they'll come in under $200 for the pair, including bushing grease. With any luck, they'll be way under that figure, but I won't know until I get an RFP response.
Let me know if you are interested and I'll have these produced and offer a warranty and a guarantee on them so you have some confidence in their appropriate performance and reliability.
Best,
David Diamond
781-771-3636
davidbdiamond@verizon.net
Since I'm in the auto suspension industry, I designed new bushings myself, reviewed them with my engineering team, and had high-quality samples made, which have worked fantastically since I put them in 6000 miles ago. The installation is pretty easy, once you've pressed out the old pillow bushings. The new ones slide into the knuckle and are dumbbell shaped (on one end), so they can't go too far. The other end has a doughnut that completes the dumbbell shape and you just bolt the bushing back into place with the original pillow bushing (and alignment) bolt. We installed two bushings in 25 minutes.
I figured that other people could benefit from avoiding the $1500 purchase of the knuckle, bushing and install, so I'll get quotes for a production run of 100 bushings and offer them for sale. I'm guessing that they'll come in under $200 for the pair, including bushing grease. With any luck, they'll be way under that figure, but I won't know until I get an RFP response.
Let me know if you are interested and I'll have these produced and offer a warranty and a guarantee on them so you have some confidence in their appropriate performance and reliability.
Best,
David Diamond
781-771-3636
davidbdiamond@verizon.net
I would definitely be interested, given that I need to replace both of mine, and am looking at over $500 of knuckle and bearing parts to replace two stupid bushings...
But how long of a lead time are we talking about? Probably several months away still? Also, I am not clear on what your concept is, is it an all metal design? I don't want these aftermarket versions with the rubber/polyurethanne, those cannot react the radial loads imparted to them.
I'd be curious to learn more.
09-04-11, 08:03 PM
#35
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OK, I'll take some pictures and post some specs tomorrow...
....I'm pretty tired tonight. BTW, turnaround will not be months. I have a small inventory already and just need to make larger volume production a priority. I'll get on the production quotes and schedule on Tuesday.
best
dd
best
dd
09-05-11, 07:13 PM
#37
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Bushing picture and details
All,
I’ll post better pictures, but here is a photo of a complete bushing, and one with the “doughnut” off of the sleeve (see below).
These bushings bear the force of a lateral arm (labeled “A”), but the bushings I got from England had the wrong shape (see below – pictures labeled A and B).
The width of A was less than the length of B, so the arm could move inappropriately in the longitudinal direction, particularly since the fat portion of B didn’t press fit into A – it just slid right in.
To make matters worse, the sleeve that the alignment bolt slides into (center of B) was too small and had to be bored out.
Instead, the Diamond bushing picture (below)
shows a metal sleeve (good for durability), with a substantial cross section (good for the second suspension arm, which is shown in the Lexus Rear Hub Diagram, to bite into).
The bushing material is racing grade polyurethane (black or red) and the narrow section of the dumbbell has a small preload.
The fat ends of the dumbbell stop the arm (A) from sliding along the bushing, yet also provide compliance for some twisting motion, just like the original pillow bushing.
The doughnut portion comes off easily so that the bushing can be easily installed – just slide the narrow portion thru the opening A, and then put the doughnut back on. The resulting bushing looks like the dumbbell bushing in the picture.
I’m also including a Lexus drawing (thank you Sewell Lexus - this diagram is also available on multiple Toyota and Lexus sites) showing where these get installed (forget the blue marking – this bushing goes in at 48730/48740 and accepts bolt 48194A).
I’ll know timing and pricing shortly.
Best regards,
dd
I’ll post better pictures, but here is a photo of a complete bushing, and one with the “doughnut” off of the sleeve (see below).
These bushings bear the force of a lateral arm (labeled “A”), but the bushings I got from England had the wrong shape (see below – pictures labeled A and B).
The width of A was less than the length of B, so the arm could move inappropriately in the longitudinal direction, particularly since the fat portion of B didn’t press fit into A – it just slid right in.
To make matters worse, the sleeve that the alignment bolt slides into (center of B) was too small and had to be bored out.
Instead, the Diamond bushing picture (below)
shows a metal sleeve (good for durability), with a substantial cross section (good for the second suspension arm, which is shown in the Lexus Rear Hub Diagram, to bite into).
The bushing material is racing grade polyurethane (black or red) and the narrow section of the dumbbell has a small preload.
The fat ends of the dumbbell stop the arm (A) from sliding along the bushing, yet also provide compliance for some twisting motion, just like the original pillow bushing.
The doughnut portion comes off easily so that the bushing can be easily installed – just slide the narrow portion thru the opening A, and then put the doughnut back on. The resulting bushing looks like the dumbbell bushing in the picture.
I’m also including a Lexus drawing (thank you Sewell Lexus - this diagram is also available on multiple Toyota and Lexus sites) showing where these get installed (forget the blue marking – this bushing goes in at 48730/48740 and accepts bolt 48194A).
I’ll know timing and pricing shortly.
Best regards,
dd
09-05-11, 07:22 PM
#38
All,
I’ll post better pictures, but here is a photo of a complete bushing, and one with the “doughnut” off of the sleeve (see below).
These bushings bear the force of a lateral arm (labeled “A”), but the bushings I got from England had the wrong shape (see below – pictures labeled A and B).
The width of A was less than the length of B, so the arm could move inappropriately in the longitudinal direction, particularly since the fat portion of B didn’t press fit into A – it just slid right in.
To make matters worse, the sleeve that the alignment bolt slides into (center of B) was too small and had to be bored out.
Instead, the Diamond bushing picture (below)
shows a metal sleeve (good for durability), with a substantial cross section (good for the second suspension arm, which is shown in the Lexus Rear Hub Diagram, to bite into).
The bushing material is racing grade polyurethane (black or red) and the narrow section of the dumbbell has a small preload.
The fat ends of the dumbbell stop the arm (A) from sliding along the bushing, yet also provide compliance for some twisting motion, just like the original pillow bushing.
The doughnut portion comes off easily so that the bushing can be easily installed – just slide the narrow portion thru the opening A, and then put the doughnut back on. The resulting bushing looks like the dumbbell bushing in the picture.
I’m also including a Lexus drawing (thank you Sewell Lexus - this diagram is also available on multiple Toyota and Lexus sites) showing where these get installed (forget the blue marking – this bushing goes in at 48730/48740 and accepts bolt 48194A).
I’ll know timing and pricing shortly.
Best regards,
dd
I’ll post better pictures, but here is a photo of a complete bushing, and one with the “doughnut” off of the sleeve (see below).
These bushings bear the force of a lateral arm (labeled “A”), but the bushings I got from England had the wrong shape (see below – pictures labeled A and B).
The width of A was less than the length of B, so the arm could move inappropriately in the longitudinal direction, particularly since the fat portion of B didn’t press fit into A – it just slid right in.
To make matters worse, the sleeve that the alignment bolt slides into (center of B) was too small and had to be bored out.
Instead, the Diamond bushing picture (below)
shows a metal sleeve (good for durability), with a substantial cross section (good for the second suspension arm, which is shown in the Lexus Rear Hub Diagram, to bite into).
The bushing material is racing grade polyurethane (black or red) and the narrow section of the dumbbell has a small preload.
The fat ends of the dumbbell stop the arm (A) from sliding along the bushing, yet also provide compliance for some twisting motion, just like the original pillow bushing.
The doughnut portion comes off easily so that the bushing can be easily installed – just slide the narrow portion thru the opening A, and then put the doughnut back on. The resulting bushing looks like the dumbbell bushing in the picture.
I’m also including a Lexus drawing (thank you Sewell Lexus - this diagram is also available on multiple Toyota and Lexus sites) showing where these get installed (forget the blue marking – this bushing goes in at 48730/48740 and accepts bolt 48194A).
I’ll know timing and pricing shortly.
Best regards,
dd
09-06-11, 06:13 AM
#39
A nylon or rubber bushing is never a replacement for a pressed spherical bearing. Furthermore a sleeve is a bad interface for something that moves everytime your suspension cycles. Even the stock rubber bushings are staked to hold the sleeve and to preload the rubber bushing, which is also loading in torsion as the suspension travels...
09-06-11, 07:36 AM
#40
The poly may "work", meaning that it will fit and will fell right when you shake the wheel with your hands, but it will not perform correctly when you throw the 3000+ lb vehicle around a turn. Alignment will move and shift all over the place, just when you need it to stay put.
I think that some type of a metallic rod-end solution is what is needed, not a compliant bushing.
09-06-11, 08:58 AM
#41
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Polyurethane isn't one material, it's a family of materials....
....so there are some polyurethanes that are not appropriate for automotive use.
But if you make the right selection, you'll get a material that doesn't abrade or corrode, doesn't rot, rust or deteriorate, has consistent performance across a broad temperature range, and scores high on durometer (firmness) measurements.
Regarding some of the comments, I considered metal and decided that I wanted some impact compliance in this bushing (not dimensional compliance), so I have 95% of stiffness of a metal part, but with better life characteristics and strong dimensional stability. There will be no change in alignment under either normal or severe driving conditions.
To test this, we aligned my car just after installation, and then took a test drive where we drifted the car in both directions, and took a 20 mile "bumpy loop" drive (including multiple speed bumps, some taken straight on, others so that each wheel had to articulate on its own) and then we measured the alignment again and saw no deviation from our original settings.
The whole point of this design was to ensure that the alignment stayed consistent during use, while eliminating the play I had in the original pillow bushings. So I appreciate the high grade for effort, but disagree with the conclusions about the weaknesses of both the material selected, and the design. This is precisely the right material (inexpensive, durable and stable) and the right design (dimensionally correct, and suspension-locating) for this application. BTW, all-metal pillow bushings run about $175 per side for similar applications (although I haven't found any that are spec'd for our cars), and with a press fit, that would put replacement and installation over $600 - too high for a bushing.
This isn't a business for me so unless there is some sort of groundswell of demand for these bushings I'll continue to try to help folks that want to try these out. I'm just trying to find inexpensive, safe and high-performance ways to keep my ride in great condition (196,000 miles and counting).
best,
dd
PS - as a postscript, note that the metal sleeve is what bears against the camber bolt, so there's one component of the metal/metal contact and stiffness sought. To see automotive-performance polyurethane applications, see www.bimmerworld.com, www.energysuspensions.com, www.prothane.com and others. Just google performance polyurethane bushings and you'll see these used by racing teams, endurance teams, and maintenance sites.
But if you make the right selection, you'll get a material that doesn't abrade or corrode, doesn't rot, rust or deteriorate, has consistent performance across a broad temperature range, and scores high on durometer (firmness) measurements.
Regarding some of the comments, I considered metal and decided that I wanted some impact compliance in this bushing (not dimensional compliance), so I have 95% of stiffness of a metal part, but with better life characteristics and strong dimensional stability. There will be no change in alignment under either normal or severe driving conditions.
To test this, we aligned my car just after installation, and then took a test drive where we drifted the car in both directions, and took a 20 mile "bumpy loop" drive (including multiple speed bumps, some taken straight on, others so that each wheel had to articulate on its own) and then we measured the alignment again and saw no deviation from our original settings.
The whole point of this design was to ensure that the alignment stayed consistent during use, while eliminating the play I had in the original pillow bushings. So I appreciate the high grade for effort, but disagree with the conclusions about the weaknesses of both the material selected, and the design. This is precisely the right material (inexpensive, durable and stable) and the right design (dimensionally correct, and suspension-locating) for this application. BTW, all-metal pillow bushings run about $175 per side for similar applications (although I haven't found any that are spec'd for our cars), and with a press fit, that would put replacement and installation over $600 - too high for a bushing.
This isn't a business for me so unless there is some sort of groundswell of demand for these bushings I'll continue to try to help folks that want to try these out. I'm just trying to find inexpensive, safe and high-performance ways to keep my ride in great condition (196,000 miles and counting).
best,
dd
PS - as a postscript, note that the metal sleeve is what bears against the camber bolt, so there's one component of the metal/metal contact and stiffness sought. To see automotive-performance polyurethane applications, see www.bimmerworld.com, www.energysuspensions.com, www.prothane.com and others. Just google performance polyurethane bushings and you'll see these used by racing teams, endurance teams, and maintenance sites.
Last edited by diamondmit; 09-06-11 at 09:05 AM.
09-06-11, 10:47 AM
#42
....so there are some polyurethanes that are not appropriate for automotive use.
But if you make the right selection, you'll get a material that doesn't abrade or corrode, doesn't rot, rust or deteriorate, has consistent performance across a broad temperature range, and scores high on durometer (firmness) measurements.
But if you make the right selection, you'll get a material that doesn't abrade or corrode, doesn't rot, rust or deteriorate, has consistent performance across a broad temperature range, and scores high on durometer (firmness) measurements.
If you look at the lower arm geometry, this outer bushing has to support most of the vehicle's weight, as well as the g-loads associated with hitting potholes etc. That is why it was an all-metal design originally. So I am a little concerned about replacing it with something that is softer. In contrast, the inner bushing of the arm sees very little load, which is why it was rubber.
I have 95% of stiffness of a metal part, but with better life characteristics and strong dimensional stability.
To test this, we aligned my car just after installation, and then took a test drive where we drifted the car in both directions, and took a 20 mile "bumpy loop" drive (including multiple speed bumps, some taken straight on, others so that each wheel had to articulate on its own) and then we measured the alignment again and saw no deviation from our original settings.
BTW, all-metal pillow bushings run about $175 per side for similar applications (although I haven't found any that are spec'd for our cars), and with a press fit, that would put replacement and installation over $600 - too high for a bushing.
This isn't a business for me so unless there is some sort of groundswell of demand for these bushings I'll continue to try to help folks that want to try these out. I'm just trying to find inexpensive, safe and high-performance ways to keep my ride in great condition (196,000 miles and counting).
I would be interested to give your design a try, before capitulating and going with two new knuckles. Do you have a pair of these available that I could try out?
09-06-11, 10:53 AM
#44
What did you try to install, the bushings in the first post? Those are in fact nothing like the stock bushings, I don't think they would work all that well in the longterm.
09-09-11, 12:07 PM
#45
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Signed product release....will get quotes soon. I also have material specs.
I just signed the product release for the bushings so I could get the mold and the quote production released. Also, I uninstalled, inspected and reinstalled the bushings and they looked great. I'm very pleased with how they perform.
Part number will be DIA2702 and I asked for these to be finished in red. Material durometer number is 95 on the Shore A scale. Sleeve is coated steel.
I'll let you know when I have some other numbers.
best
dd
Part number will be DIA2702 and I asked for these to be finished in red. Material durometer number is 95 on the Shore A scale. Sleeve is coated steel.
I'll let you know when I have some other numbers.
best
dd