Re: Trailing arm shim question
This is one of the examples I use in the Advanced Judging School. The hole for the cotter pin appeared in the AIM and frames during 1969 model year, yet the cotter pin didn't appear on the cars until the last week of 1970 model year production. This is one example of why the dates given for changes in the AIM sometimes mean little. The cars always tell the real story -- but getting enough examples to have a meaningful database is a challenge.
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Terry -
Re: Trailing arm shim question - Terry
Terry, my very original 1970 that was built on the next-to-last-day of production has the slotted shim. The shim is oriented such that the open end of the slot is visible (the open end of the slot is pointing more toward the ground than up). Memory tells me that someone once told me that my shims are installed wrong, that the open end of the slot should be the other way around. I am fairly certain that the shims on my car are as they were installed at the factory. Have you ever seen the slotted shims installed this way on the first 1970 cars to get them? If not, is it possible that since my car may have been one of the first 1970 cars to get the new slotted shims, that perhaps the first few could have been installed incorrectly at the factory? Your thoughts are appreciated.
Alan -
Re: Trailing arm shim question - Terry
Terry, my very original 1970 that was built on the next-to-last-day of production has the slotted shim. The shim is oriented such that the open end of the slot is visible (the open end of the slot is pointing more toward the ground than up). Memory tells me that someone once told me that my shims are installed wrong, that the open end of the slot should be the other way around. I am fairly certain that the shims on my car are as they were installed at the factory. Have you ever seen the slotted shims installed this way on the first 1970 cars to get them? If not, is it possible that since my car may have been one of the first 1970 cars to get the new slotted shims, that perhaps the first few could have been installed incorrectly at the factory? Your thoughts are appreciated.
AlanComment
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Re: Trailing arm shim question
Thanks for the info on my 69 questions. To get this kind of help for the price of NCRS membership is a bargain!!!Comment
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Re: Trailing arm shim question
Thanks for the info on my 69 questions. To get this kind of help for the price of NCRS membership is a bargain!!!Comment
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Re: Trailing arm shim question - Terry
It has been a while since we did that research, and I don't want to rely on my memory -- and I don't have the TIM&JG with me either. We may have put the change point for the install of the cotter pin even later than the last week of 1970 production -- it well might have been the last few days of 1970 production.
I take it your car does not have the cotter pin since as you describe the install of the shims they are captive. The purpose of the cotter pin is to keep the shims from falling out when they are installed slotted end first -- although in most cases (if not all) the shims can be tucked into the frame pocket to help hold them in place. The problem is that as the trailing arm works it way up and down the shims can creep up and thus risk slipping out of place.
Prior to the install of the shims slotted end first and thus the use of the cotter pin; C3 trailing arm shims were installed with the hole first, thus locking them in.
The key is -- if you believe the installation of your trailing arm shims are original, or like the original -- don't worry, be happy.TerryComment
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Re: Trailing arm shim question - Terry
It has been a while since we did that research, and I don't want to rely on my memory -- and I don't have the TIM&JG with me either. We may have put the change point for the install of the cotter pin even later than the last week of 1970 production -- it well might have been the last few days of 1970 production.
I take it your car does not have the cotter pin since as you describe the install of the shims they are captive. The purpose of the cotter pin is to keep the shims from falling out when they are installed slotted end first -- although in most cases (if not all) the shims can be tucked into the frame pocket to help hold them in place. The problem is that as the trailing arm works it way up and down the shims can creep up and thus risk slipping out of place.
Prior to the install of the shims slotted end first and thus the use of the cotter pin; C3 trailing arm shims were installed with the hole first, thus locking them in.
The key is -- if you believe the installation of your trailing arm shims are original, or like the original -- don't worry, be happy.TerryComment
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Re: Trailing arm shim question - Terry
Alan, what's the last three of your serial number? As I recall, our cars were built the same day, or G30. If I remember correctly, my shims were installed slotted end on the pivot bolt, and also were secured by BA cotter pins...that's the only way I would known about the world's largest, least utilized cotter pins, was to actually have seen them.
This aspect of my car caused some consternation at first, because at the time there was no literature, vendor catalogs, etc showing the slotted shims used in 70. I thought later alignment techs had traded shims for the later shims, but the cotter pins would probably have been discarded in that case. Only later, maybe from communication with Terry or from the 3rd Edition, did it become clear that the shims were original. This re-emphasizes the saying...if the feature LOOKS like the factory did it, then don't doubt the car.Comment
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Re: Trailing arm shim question - Terry
Alan, what's the last three of your serial number? As I recall, our cars were built the same day, or G30. If I remember correctly, my shims were installed slotted end on the pivot bolt, and also were secured by BA cotter pins...that's the only way I would known about the world's largest, least utilized cotter pins, was to actually have seen them.
This aspect of my car caused some consternation at first, because at the time there was no literature, vendor catalogs, etc showing the slotted shims used in 70. I thought later alignment techs had traded shims for the later shims, but the cotter pins would probably have been discarded in that case. Only later, maybe from communication with Terry or from the 3rd Edition, did it become clear that the shims were original. This re-emphasizes the saying...if the feature LOOKS like the factory did it, then don't doubt the car.Comment
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Re: Trailing arm shim question - Terry
Terry, thanks for the information. I do not have access to my car right now and cannot for the life of me remember exactly how the shims are held in place. I do recall the judging manual (I think the old 2nd edition) having a diagram of the two types of shims, the first type having a hole in one end and the other type being slotted with a hole on the other end. Since I have the slotted shims, and since the shims are installed with the slotted end visible (not slotted end first), I assume that a bolt or some type of cotter pin is inserted in the other end that has the hole and that is what keeps the shim from falling out. That is what I cannot remember - what holds the shim in place, a bolt or cotter pin or possibly a combination. Regardless, based on the originality of the car, I do believe the shims have never been out and were installed with the slotted end last.Comment
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Re: Trailing arm shim question - Terry
Terry, thanks for the information. I do not have access to my car right now and cannot for the life of me remember exactly how the shims are held in place. I do recall the judging manual (I think the old 2nd edition) having a diagram of the two types of shims, the first type having a hole in one end and the other type being slotted with a hole on the other end. Since I have the slotted shims, and since the shims are installed with the slotted end visible (not slotted end first), I assume that a bolt or some type of cotter pin is inserted in the other end that has the hole and that is what keeps the shim from falling out. That is what I cannot remember - what holds the shim in place, a bolt or cotter pin or possibly a combination. Regardless, based on the originality of the car, I do believe the shims have never been out and were installed with the slotted end last.Comment
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Re: Trailing arm shim question - Terry
Chuck, it is 165. Can you clarify what you said, that your shims were installed slotted end on the pivot bolt and were also secured by cotter pins? Does that mean that the shims were installed slotted end first or slotted end last? As I said (see my prior answer to Terry's message), mine were installed slotted end last and I assume that either a bolt or cotter pin (I can't remember exactly how) ran through the hole on the other end of the shim that was inserted first and that held it in place. It may be that if our cars were among the very first 1970 cars to get the slotted shims, the guys on the line were figuring out which way to install them. Neat stuff!Comment
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Re: Trailing arm shim question - Terry
Chuck, it is 165. Can you clarify what you said, that your shims were installed slotted end on the pivot bolt and were also secured by cotter pins? Does that mean that the shims were installed slotted end first or slotted end last? As I said (see my prior answer to Terry's message), mine were installed slotted end last and I assume that either a bolt or cotter pin (I can't remember exactly how) ran through the hole on the other end of the shim that was inserted first and that held it in place. It may be that if our cars were among the very first 1970 cars to get the slotted shims, the guys on the line were figuring out which way to install them. Neat stuff!Comment
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Re: Trailing arm shim question - Terry
Mine is 074...they would have been on the line at the same time.
What I was saying is that my shim installation, as I remember it, was according to the AIM, UPC 4, Sheet A4; i.e. the slotted end of the shims over the pivot bolt on either side of the control arm end, and the closed hole end retained to the frame with a LARGE cotter pin.
The shims do not move with the control arm although the ends are supported by the pivot bolt...they are held stationary, and simply reduce the width of the "slot" in the frame for the control arm. The positioning of the shims creates an "adjusted width" slot for the control arm, positioned in the frame to provide proper alignment.
However...As I think about it, I can't remember seeing "those" cotter pins in a long time. I wouldn't have thrown them away...cotters pins that big are useful for conversation if nothing else. Let me check my boxes, and get back to you...it's possible my memory is conforming to the AIM, but I definitely had the slotted shims. (Hey, Patrick..How about that drug name; I promise not to sue you for malpractice...Besides, I would have to pay you for that to happen. )Comment
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Re: Trailing arm shim question - Terry
Mine is 074...they would have been on the line at the same time.
What I was saying is that my shim installation, as I remember it, was according to the AIM, UPC 4, Sheet A4; i.e. the slotted end of the shims over the pivot bolt on either side of the control arm end, and the closed hole end retained to the frame with a LARGE cotter pin.
The shims do not move with the control arm although the ends are supported by the pivot bolt...they are held stationary, and simply reduce the width of the "slot" in the frame for the control arm. The positioning of the shims creates an "adjusted width" slot for the control arm, positioned in the frame to provide proper alignment.
However...As I think about it, I can't remember seeing "those" cotter pins in a long time. I wouldn't have thrown them away...cotters pins that big are useful for conversation if nothing else. Let me check my boxes, and get back to you...it's possible my memory is conforming to the AIM, but I definitely had the slotted shims. (Hey, Patrick..How about that drug name; I promise not to sue you for malpractice...Besides, I would have to pay you for that to happen. )Comment
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