MGB & GT Forum
Front Suspension Rebuild
Posted by rglosem
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Topic Creator (OP)
Jan 4, 2024 07:05 AM
Joined 4 years ago
127 Posts
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I am in the process of rebuilding the front suspension on my 1972 MGB. I have everything apart and cleaned/inspected, getting ready to rebuild, have a few questions I’d like to get input on:
1) On my car and in many of the videos I have watched, seems like many use the “red grease” on the stub axle, bearings, kingpin, etc. What is this red grease? Is that what is recommended?
2) It looks like the mounting pads for the front crossmember are shot. I figure it’s a no-brainer to replace them while the suspension is off. I don’t want to remove or disturb the crossmember too much. What’s the best way to replace the mounting pads one side at a time?
3) Does anyone have any tricks, jigs, etc. recommendations to press out the old kingpin bushings and install the new ones?
I purchased the major suspension kit from Moss.
Thanks.
Knowledge is what you get when you read the fine print. Education is what you get when you don't.
1) On my car and in many of the videos I have watched, seems like many use the “red grease” on the stub axle, bearings, kingpin, etc. What is this red grease? Is that what is recommended?
2) It looks like the mounting pads for the front crossmember are shot. I figure it’s a no-brainer to replace them while the suspension is off. I don’t want to remove or disturb the crossmember too much. What’s the best way to replace the mounting pads one side at a time?
3) Does anyone have any tricks, jigs, etc. recommendations to press out the old kingpin bushings and install the new ones?
I purchased the major suspension kit from Moss.
Thanks.
Knowledge is what you get when you read the fine print. Education is what you get when you don't.
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allanreeling
Allan R
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Jan 4, 2024 09:15 AM
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Jan 4, 2024 09:25 AM
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Not difficult, but here are a few pointers-
King pin bushings have to be reamed to size after installation, and the factory reamer is expensive. You may want to source rebuilt swivel axles instead. Or, see how well a new kingpin fits the old bushings. Usually though the kingpin is pitted and tears up the bushing.
When disassembling you have to consider spring tension; easiest method is to support vehicle on stands (under unibody rail at the base of the firewall), then place a floor jack under the spring pan. Jack until weight is just on the floor jack, then unbolt the lever shock from the subframe. Lower the floor jack and the suspension will swing down and allow spring removal. Have to disconnect the caliper and sway bar link first.
Crossmember pads might be difficult without removing the crossmember; it depends which nut comes loose on the mounting studs. Once the suspension is off of both sides, there are only the 4 rack and pinion bolts and the steering shaft u-joint to remove the rack. Then drop the entire crossmember.
Replace every rubber bit and it should be good for a long time. I don’t recommend poly unless you are racing.
King pin bushings have to be reamed to size after installation, and the factory reamer is expensive. You may want to source rebuilt swivel axles instead. Or, see how well a new kingpin fits the old bushings. Usually though the kingpin is pitted and tears up the bushing.
When disassembling you have to consider spring tension; easiest method is to support vehicle on stands (under unibody rail at the base of the firewall), then place a floor jack under the spring pan. Jack until weight is just on the floor jack, then unbolt the lever shock from the subframe. Lower the floor jack and the suspension will swing down and allow spring removal. Have to disconnect the caliper and sway bar link first.
Crossmember pads might be difficult without removing the crossmember; it depends which nut comes loose on the mounting studs. Once the suspension is off of both sides, there are only the 4 rack and pinion bolts and the steering shaft u-joint to remove the rack. Then drop the entire crossmember.
Replace every rubber bit and it should be good for a long time. I don’t recommend poly unless you are racing.
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Jan 4, 2024 09:47 AM
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Joined 21 years ago
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In reply to # 4745071 by RGK20m3
...King pin bushings have to be reamed to size after installation, and the factory reamer is expensive. You may want to source rebuilt swivel axles instead. Or, see how well a new kingpin fits the old bushings....
Good advice. I took my swivel axle, king pins, and bushings to a local machinist. He installed and reamed the bushings for less than the cost of rebuilt swivel axles. He is very experienced but this was his first exposure to MG swivel axles. He said it was a difficult job, but to his credit, he stuck with his original estimate.|
Jan 4, 2024 06:43 PM
Joined 15 years ago
36,362 Posts
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"I don’t recommend poly unless you are racing."
I don't race and have Superpro all round so YMMV.
OP some suggest dropping the xmember enough to slide new pads in having split them from the centre hole to edge - this is not an option I would choose.
Mk1: CKD 11/66 first registered 8/5/67; owned since 3/77. 18GB +40 balanced. Peter Burgess BVFR head. Piper 285. 123. FidanzaFW. 4synch c/r box. Superpro. Nut and bolt rebuild 2010 - 2015. Tartan Red.
GT: 12/78. VW Golf guards, flush fit front and rear valances, frenched indicators, Mk1 rear lights - LED lights. 'Worked' Rover V8, Monsoon ECU for EFI. Commodore VSV8 GM4L60E, Lokar tiptronic shifter & Quick4 controller. Vintage Air A/C. FC IFS. CCE 4 link rear. Salisbury with Quaife. Jaguar Storm.
I don't race and have Superpro all round so YMMV.
OP some suggest dropping the xmember enough to slide new pads in having split them from the centre hole to edge - this is not an option I would choose.
Mk1: CKD 11/66 first registered 8/5/67; owned since 3/77. 18GB +40 balanced. Peter Burgess BVFR head. Piper 285. 123. FidanzaFW. 4synch c/r box. Superpro. Nut and bolt rebuild 2010 - 2015. Tartan Red.
GT: 12/78. VW Golf guards, flush fit front and rear valances, frenched indicators, Mk1 rear lights - LED lights. 'Worked' Rover V8, Monsoon ECU for EFI. Commodore VSV8 GM4L60E, Lokar tiptronic shifter & Quick4 controller. Vintage Air A/C. FC IFS. CCE 4 link rear. Salisbury with Quaife. Jaguar Storm.
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Jan 4, 2024 07:01 PM
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Magee, MS, USA
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Jan 5, 2024 06:06 AM
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This is a simple cross member mod to do while the cross member is out. This will save many 4 letter words during the install process.
CAUTION!!
Life's uncertain, eat dessert first
Know the rules well so you can break them effectively. Dalai Lama
Journal index
https://www.mgexp.com/journal/Charles-Durning.2966/toc
CAUTION!!
Life's uncertain, eat dessert first
Know the rules well so you can break them effectively. Dalai Lama
Journal index
https://www.mgexp.com/journal/Charles-Durning.2966/toc
Attachments:
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Jan 5, 2024 10:06 AM
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Joined 15 years ago
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This MGB front spring removal procedure, with photos, may prove useful for you:
https://1drv.ms/b/s!Ak8cjmHVwcHXlgKbkLV4_xZX9ohz?e=A3mEyP
https://1drv.ms/b/s!Ak8cjmHVwcHXlgKbkLV4_xZX9ohz?e=A3mEyP
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Jan 5, 2024 11:03 AM
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Joined 20 years ago
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Easy enough to drop the crossmember fit new buffers, I recommend synthetic buffers. Do not disturb the top nuts on the four pins, leave those in place and just undo the bottom nuts leaving the pins in the channels, just put a wrench on the topside nut to keep things from moving. I find it easier to disassemble/assemble the crossmember on the car.
On reassembly, to tighten the bottom nuts on the pins, again put a wrench on the top nut to keep it from moving. Tighten the bottom nut until you get a reasonable/good squish of the buffers, do not use a torque setting for this bottom nut.
On reassembly, to tighten the bottom nuts on the pins, again put a wrench on the top nut to keep it from moving. Tighten the bottom nut until you get a reasonable/good squish of the buffers, do not use a torque setting for this bottom nut.
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Jan 5, 2024 11:12 AM
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Joined 21 years ago
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In reply to # 4745035 by rglosem
1) On my car and in many of the videos I have watched, seems like many use the “red grease” on the stub axle, bearings, kingpin, etc. What is this red grease? Is that what is recommended?
1) On my car and in many of the videos I have watched, seems like many use the “red grease” on the stub axle, bearings, kingpin, etc. What is this red grease? Is that what is recommended?
I know of at least one Pro British car mechanic that uses Kendall L-427 Super Blu Grease on the front bearings. I use it on my MGB & my Harley Timken wheel bearings.
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Arizona Shorty
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Jan 5, 2024 12:00 PM
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Red grease is a multi-purpose, extreme pressure, synthetic, lithium based grease, and while perhaps intended for things like disc brake applications where high temps are normal, it is used for just about everything you need a grease for. Lucas Red 'N' Tacky is one such.
The cross member pads are not all that hard to do without dismounting the cross member. You can, as suggested, leave the top nuts in place, remove the bottom nuts, and press the pin upward until the pads are free to remove and replace. I just pulled the bolts entirely because when working on old machines like these, I clean and paint things as I go, including nuts and bolts. Up to you.
I used poly bushings, and do not have a race car. Again, this is up to you. If you already have the major kit, use what came with it. Poly is not as compliant as rubber, and for everyday use, may result in a slightly harsher ride and probably a bit more noise out of the body. In suspension points, poly definitely transmits more road shock, but results in tighter handling. If you don't like the result using what came in the kit, you will at least know how to change out the bushings.
If it where my project, I would not try to ream the king pin bushings, because it is a fairly technical, and critical step that needs to be done right the first time. Find a machine shop.
GMc
The cross member pads are not all that hard to do without dismounting the cross member. You can, as suggested, leave the top nuts in place, remove the bottom nuts, and press the pin upward until the pads are free to remove and replace. I just pulled the bolts entirely because when working on old machines like these, I clean and paint things as I go, including nuts and bolts. Up to you.
I used poly bushings, and do not have a race car. Again, this is up to you. If you already have the major kit, use what came with it. Poly is not as compliant as rubber, and for everyday use, may result in a slightly harsher ride and probably a bit more noise out of the body. In suspension points, poly definitely transmits more road shock, but results in tighter handling. If you don't like the result using what came in the kit, you will at least know how to change out the bushings.
If it where my project, I would not try to ream the king pin bushings, because it is a fairly technical, and critical step that needs to be done right the first time. Find a machine shop.
GMc
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Jan 5, 2024 12:29 PM
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Joined 14 years ago
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In reply to # 4745489 by ClayJ
Easy enough to drop the crossmember fit new buffers, I recommend synthetic buffers. Do not disturb the top nuts on the four pins, leave those in place and just undo the bottom nuts leaving the pins in the channels, just put a wrench on the topside nut to keep things from moving. I find it easier to disassemble/assemble the crossmember on the car.
On reassembly, to tighten the bottom nuts on the pins, again put a wrench on the top nut to keep it from moving. Tighten the bottom nut until you get a reasonable/good squish of the buffers, do not use a torque setting for this bottom nut.
On reassembly, to tighten the bottom nuts on the pins, again put a wrench on the top nut to keep it from moving. Tighten the bottom nut until you get a reasonable/good squish of the buffers, do not use a torque setting for this bottom nut.
+1 Clay.
That's exactly how I've always done it.
Use only the polyurethane pads. You're free to use the very cheap "rubber" (or whatever they're made of) pads, but only if you really want to re-do this somewhat finicky job every three or four years. Those are not worth the hassle.
I can't understand why some say those poly pads are "only for racing" or that they give a harsh ride. That's just not true. I have the SuperPro crossmember pads and they are perfectly fine for my street driven MGB. No harshness or any other downside to them. I've also had the red poly Prothane brand, they were just fine also.
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Jan 5, 2024 09:02 PM
Joined 15 years ago
394 Posts
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I'm pretty sure Caldwell will rebuild your spindles for you, and they do great work. While you're in there, they do shocks too:
https://www.nosimport.com/british-cars-nos-parts/British-bmc-austin-mg-morris/mgb-parts?product_id=1284
https://www.nosimport.com/british-cars-nos-parts/British-bmc-austin-mg-morris/mgb-parts?product_id=1284
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Arizona Shorty
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Jan 5, 2024 10:01 PM
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"I can't understand why some say those poly pads are "only for racing" or that they give a harsh ride."
It has to do with compliance. Poly is not very compliant. Rubber is almost alway far more compliant than poly. Shock of any sort passes from piece to piece throughout the car. Where two parts are held apart by rubber, shock is transmitted slowly due to higher compliance. Hence a "softer" experience. This is simply a result of physics. A car using poly bushings will transmit road shock or engine vibration faster and more fully than a car using rubber.
How much faster, how much softer or slower. Is the difference significant? Depends on your intended use. And you need a durometer to measure differences. Auto manufacturers use rubber bushings. They don't want to hear complaints about rough rides and noise. Racers use poly. They want faster response times and tighter handling, noise and harshness not being that important.
Use whichever product you think fits your driving style and your needs. The only negative about rubber might be from low quality Chinese crap being passed off as new parts. I suspect even inexpensive poly is higher quality than offshore rubber.
GMc
It has to do with compliance. Poly is not very compliant. Rubber is almost alway far more compliant than poly. Shock of any sort passes from piece to piece throughout the car. Where two parts are held apart by rubber, shock is transmitted slowly due to higher compliance. Hence a "softer" experience. This is simply a result of physics. A car using poly bushings will transmit road shock or engine vibration faster and more fully than a car using rubber.
How much faster, how much softer or slower. Is the difference significant? Depends on your intended use. And you need a durometer to measure differences. Auto manufacturers use rubber bushings. They don't want to hear complaints about rough rides and noise. Racers use poly. They want faster response times and tighter handling, noise and harshness not being that important.
Use whichever product you think fits your driving style and your needs. The only negative about rubber might be from low quality Chinese crap being passed off as new parts. I suspect even inexpensive poly is higher quality than offshore rubber.
GMc
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Jan 6, 2024 06:08 AM
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Joined 9 years ago
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You may be beyond this, but I'm posting this excellent guide from my bookmarks. I see it in my future.
https://www.mgexp.com/forum/mgb-and-gt-forum.1/how-to-remove-the-mgb-front-suspension-or.4529436/
I'd rather wear out than rust out.
"If everyone is thinking alike, then somebody isn't thinking." General George Smith Patton
https://www.mgexp.com/forum/mgb-and-gt-forum.1/how-to-remove-the-mgb-front-suspension-or.4529436/
I'd rather wear out than rust out.
"If everyone is thinking alike, then somebody isn't thinking." General George Smith Patton
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