After rebuilding my rear axle (new bushings, springs and shocks) I've got a terrible knocking sound. The knocking comes from where the upper arm is attached to the axle. There's a little gap between the bolt and the inside of the new bushing, This makes a small movement between the arm and attachment on the axle and a terrible knocking sound. Any ideas how to cure this?
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Noise from upper control arm
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Gunnar S - 58 Thunderbird
http://squarebirds.org/users/gunnar/...bird/index.htm
http://www.tbirdregistry.com/viewdat...tryNumber=5569Tags: None -
I didn't get much response on this so I will try to explain a bit better. On the picture you can see what bolt who makes the knocking sound, it's marked with red arrow. This happens on both side when the upper arms is exposed for changes between push and pull forces, when moving the car up and down. I can feel and see the horizontal movement between the upper arm and the attach on the rear axle. The size of the bolt is a bit to thin compare to the diameter inside the new bushing.
Is this difference between bolt and bushing normal. Do I have to use extremely force on this bolt to stop this movement? (I have already used a good portion force but I'm afraid to damage the bolt). Or do I have to find a mechanical workshop that can produce an new bolt with exactly dimensions?Attached Filessigpic
Gunnar S - 58 Thunderbird
http://squarebirds.org/users/gunnar/...bird/index.htm
http://www.tbirdregistry.com/viewdat...tryNumber=5569 -
Gunnar, the reason nobody responded is our fault. Not many Squarebirds are from 1958 (with coil rear suspension), so replacement parts are 'through the roof' as we yanks say.
Anders in Sweden, did extensive engineering on his '58 rear suspension, and he had urethane bushings made in Sweden.
Before he assembled the bushings, he checked the geometry of his suspension by raising and lowering the axle under no load. He found that the original design has flaws that cause binding.
Go to the thread Anders made:
Anders is a very good engineer and he did deep extensive research on this rear axle assembly.
If my memory is right, the 'clapper' portion needs to be loose or the upper arms will bind and eventually break! I do not have one of these cars but if I did, I would leave the big urethane bushing out, to give the upper arms freedom of the full range of motion. If that urethane center bolt is tight, all the stress transfers to the upper arms.
I am from Ford Motor Company, but I believe Budd Company did the engineering and design of this axle. Ford approved it. After only one year, Ford quickly went back to leaf springs in 1959. In my opinion, coil springs offer a smoother ride. Ford recognized this setup is not right. Instead of spending more money to engineer and build a corrected version, Ford went back to using leaf springs.
Because only one year and only one model used these bushings, the demand is very low which makes aftermarket prices very high, if you can find the bushings at all.
As a side thought; this 'clapper' system on the '58 Thunderbird rear axle is unique. I have never seen it on any other car before or since that model. In a normal axle setup, the coil springs and shock absorbers are directly bolted to a pad (a perch) welded to the axle housing. Leaf spring systems are the same. The leaf assemblies are directly bolted to the axle housing with long "U" bolts. I hope this helps. - DaveMember, Sons of the American Revolution
CLICK HERE to see my custom hydraulic roller 390 FE build.
"We've got to pause and ask ourselves: How much clean air do we need?"
--Lee Iacocca
From: Royal Oak, MichiganComment
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There's a little gap between the bolt and the inside of the new bushing,Comment
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I have read with interest the original thread from Gunnar and the posts from our members Dave / Joe, as my wife has a 58.
The technical information provided by some of our members to others is incredible. That is why I believe this is the BEST site for Thunderbirds on the planet. Good stuff guysDano Calgary,Alberta Canada
Thunderbird Registry
58HT #33317
60 HT (Sold )Comment
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To be perfectly honest, if my '58 coil spring setup needed bushings, with the prices the vendors are asking for replacements, I would convert it to a leaf spring setup. No, it would not be stock for a '58 but the end result would be identical to a '59 and '60 Squarebird. The conversion cost is low because parts are commonly available and no further maintenance is necessary.
I advocate for 'better function & lower cost' over being a 'purist'. - DaveMember, Sons of the American Revolution
CLICK HERE to see my custom hydraulic roller 390 FE build.
"We've got to pause and ask ourselves: How much clean air do we need?"
--Lee Iacocca
From: Royal Oak, MichiganComment
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Thanks for all replies.
Dave, I've already spend a lot of money to make this working.... so I still hope to make it work. And I'm pretty sure that this don't have anything to do with the problem Anders had. There is almost no pressure at these rubber bushings on my car now.
I've studied this and have found out that the problem probably occurs because of the new coils. With the old coils (even with extra coil-overs) the car was 1 - 1,5" lower at the rear. The old coils was never able to lift the car up to the level where the upper arms changes between push and tensile forces and the bushings had always one way load.
With the new springs and full load at the rear axle, I can easily remove the bolt from the upper arm bushing and put it back again without any forces on the bolt. I guess this is ideally for the upper arms, but make the problem that it's possible for the bolt to move a bit inside the bushings when the car moves up and down. I suspect that the new bushings are a bit shorter (very little) compare to the old ones and makes it more difficult to lock the bushing to the attachment. I've have now used even more force to tightening the bolts and it have solved the problem partly. I also suspect that the bushings on the lower arms also make some "knocks" from time to time. I plan to go to a friend that can lift the car so we can work from the underside and get more force on the bolts.
I will let you know the result when it's done.sigpic
Gunnar S - 58 Thunderbird
http://squarebirds.org/users/gunnar/...bird/index.htm
http://www.tbirdregistry.com/viewdat...tryNumber=5569Comment
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Rear Suspension 58 Birdy
Did you buy replacement bushings from one of the suppliers in the US or did you fabricate a set in Norway.
The piece you are talking about should have a sleeve in the rubber between the bolt and the bushing.
The company in the US is called Rare Parts. Best material for the bushings is urethane. Very stiff but keeps all the rear end parts in line.
My guess is the metal sleeve is missing and the metal sleeve is missing from the rear of the control arms as well. There was a Ford recall on the rear suspension where they instructed the dealers to make the hole in the control arm bigger.. The arm was cut with a torch making a jagged hole.
Anders managed to fabricate his own set of bushings and sleeves and solved the problems with the rear end on his 58.
Good Luck
Fuz
58's&64's
Sun Prairie,Wi.
tmjsong1@aol.comComment
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I guess the easiest way to explain my meaning is to remove the springs and lift/lower the axle. You want to see full range of motion, from the rubber stop at the top, to fully extended shock absorbers, which is the 'bottom stop.'
Fuzz is right about that bushing length in the 'clapper' as I call it. Some of our members have tightened the bolts only to find the ride became very stiff and eventually ripped the upper arm mounting bolt out of the frame, or sheared the upper arm off. This isn't tensile or torsion, but shear stress.
The upper and lower arms are simply two sides of a parallelogram. The other two sides are the axle and frame of the car. They keep the axle parallel and square to the engine and driveline.
Here is Ander's axle with no springs or shock absorbers:
If you tighten the 'clapper' bushings, in effect, that makes the lower pivot point solid which forces the axle to roll and that puts shear tension on the upper arms.
The 'clapper' system needs to be very loose, to work well. Personally, I don't know why a bushing needs to be there at. If it were mine, I would leave this area empty because the bushing offers no suspension strength. Full axle extension and wheel bounce is the job of your shock absorbers.
I think of it this way... Look at the picture; if I cut the clapper off altogether, the result would be a modern coil spring setup. - DaveMember, Sons of the American Revolution
CLICK HERE to see my custom hydraulic roller 390 FE build.
"We've got to pause and ask ourselves: How much clean air do we need?"
--Lee Iacocca
From: Royal Oak, MichiganComment
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The bushings is US parts ordered from Rare Parts. This set is not 100%....
First, the sleeves for this "clapper" system is too short and after try using this it ended by smashing the new rubber completely as Dave also told in the posting under. See also my first picture with the new and old sleeve together with the damaged rubber. I ended to put back the old sleeve and the old rubber which now works very well. I've also tried to remove the clapper system with no help.
My problems is in the areas marked with red circles in the second picture. If you for example look at the red circle up to the right, the problem is that the new sleeve(5504) is about 0,01" wider inside compare to the old and there's space for the bolt(45534-5) to move horizontal inside the sleeve. The new sleeve is also shorter (very little, haven't measured) and makes it difficult to tightening the bolt to get enough pressure between the attachment(5503) and the sleeve to prevent this movement. This is what make this knocking sound.
I think the only solution is to jacking the car so high up so its possible to stand under and use more force on the bolts and hope that they don't break....
I will let you know when it's done.sigpic
Gunnar S - 58 Thunderbird
http://squarebirds.org/users/gunnar/...bird/index.htm
http://www.tbirdregistry.com/viewdat...tryNumber=5569Comment
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All sleeves should fit snugly inside the mounting brackets and all bolts should tighten the sleeves so they do not turn. The rubber should rotate on the sleeve.
The proper way to do tighten is to let the car sit level, then tighten the sleeves. The bolts do not require excessive torque and they are all standard SAE sizes.
Replacement bushings should come with correct-length sleeves.
Again, the bolts hold the sleeves stationary. Sleeves do not rotate on bolts. All torsion is done in the urethane rubber. We tighten with the body sitting at a natural height so the urethane can rotate in both directions equally. - DaveMember, Sons of the American Revolution
CLICK HERE to see my custom hydraulic roller 390 FE build.
"We've got to pause and ask ourselves: How much clean air do we need?"
--Lee Iacocca
From: Royal Oak, MichiganComment
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After rebuilding my rear axle (new bushings, springs and shocks) I've got a terrible knocking sound. The knocking comes from where the upper arm is attached to the axle. There's a little gap between the bolt and the inside of the new bushing, This makes a small movement between the arm and attachment on the axle and a terrible knocking sound. Any ideas how to cure this?Comment
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Anders, I've read your threads over and over again,but can't still find out hove to solve this.
A few days ago I visited a workshop, lifted the car standing on its wheels and tightened all bolts attached to bushings in the rear. But I still have this knocking sound. Its now impossible to provoke sound by rocking the car. It only happens when driving the car on a bumpy road.
How do I find out if something is wrong with the attachment for the upper arm to the frame? Everything seems to be OK. I can tighten and loosen the bolt without finding anything unusual.
I've started to think the same as you did, maybe it's better to sell the car and buy something else....sigpic
Gunnar S - 58 Thunderbird
http://squarebirds.org/users/gunnar/...bird/index.htm
http://www.tbirdregistry.com/viewdat...tryNumber=5569Comment
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maybe just change it over to leaf springs...Comment
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