Topic: 67-70 Front Frame Measurements~ Upper Arm Mounting Area

[67gtasanjose]

My 67 Mustang's body, like many others, has had it's share of rough driving conditions over it's lifetime and I wish to verify and realign things while it is all apart. I found the frame measurements for the 67-70's in the Library Section, http://concoursmustang.com/speegle/Instructions/Instructions-Frame_Dimensions.pdf 
...but I have some questions, since it is difficult to see things in 3-dimensions.

I have measurements from my 67 that do not match up with my interpretation of the PDF file mentioned.

PLEASE, if anyone has a 67-70 (except B9-er) apart and can check your measurements, maybe I can figure this out before I begin to paint or reassemble my car.

This morning, I measured X-measurements from 2 locations between the Upper Control Arm forward bolt holes to the idler arm holes, so both upper and lower holes and the 2nd set from between the upper control arm forward hole and the steering gear forward 2 holes. I also obtained a straight across measurement between the right shock tower, upper control arm hole(s) and the left shock tower upper control arm hole(s)  (NOTE: no suspension or steering components, also no engine, so this is an empty hull on a rotisserie) 

Measurements I read are as follows:
    1a.) LH Shock Tower, upper arm forward hole to Idler arm lower hole= 31-7/8"
    1b.) LH Shock Tower, upper arm forward hole to Idler arm upper hole= 30-7/8"

    2a.) RH Shock Tower, upper arm forward hole to Steering gear lower hole= 31-1/4"
    2b.) RH Shock Tower, upper arm forward hole to Steering gear upper hole= 30-1/4"

    3a&b) Distance between upper control arm forward bolt hole (Right Side to Left Side) and upper control arm rear holes (also side to side) both measure the same at this time. 27-1/2"
                   
I see that there looks to be just over a half inch variation from right to left when comparing these measurements and picturing the suspension as a tandem pair of geometric dimensions.

FWIW, I noticed that the two forward holes of the gear box happen to be exactly across from the two holes of the idler arm mounting bracket. Coincidence? I do not think so. This looks engineered into the design. If I am correct, this should be a perfect location to make my X-measurements from. This is why I feel my RH upper arm is off a little.

Since I am not sure the PDF file looks accurate in my area of interest, maybe I am reading it incorrectly?     

Obviously, my area of concern is the RH shock tower, specifically in getting the alignment correct for the upper control arm mounting. Two incidents I know about, have caused this particular item to have been tweaked. It had even cracked at one point in time but the crack has been professionally welded several years ago, last time the engine was out, fenders off and the upper arm was removed. From the engine bay area, the welder did a virtually undetectable weld on the crack. His job there looks awesome. The ONLY problem with the repair was that the area that had cracked was simply porta-powered (by me) from across the engine bay to press the crack closed...no X-measurements were taken. I only matched the distances between the two upper arm holes, as verified with todays measurements.  This means I cannot prove it was pressed into place correctly. I would like to verify correctness now.

I did have a wheel alignment done after this welding job was done and though the car drove straight afterwards, I felt afterwards that the UCA mounting was off, mostly because the strut rod adjustment viably didn't match up to the drivers side following the alignent, it had to be adjusted over 1/2 inch (forward or back, I cannot remember right now) to get the caster setting of the alignment evened up. Usually, a "straight" body car the caster adjustments are not NOTICABLY different following an alignment.

I could use the measurements like what i mentioned above including from between the upper control arms, across the engine bay if those numbers might be available too. Maybe these X-measurements could help with getting this corrected or verified.

Any help appreciated. If you have one of these apart right now, it would help to see what you find on yours.

Thanks in advance. Richard

[67gtasanjose]

Since I didn't even hear "crickets chirping" on this one...I edited the title and added some more info.

[cobrajetchris]

The easiest way that I have found to measure the shock tower alignment is using an original export brace and bolting it up. This serves as a fixture and if your towers are out of alignment it will not bolt up. The lower cross brace (commonly called the belly bar) is another part to install to see if the lower rails are in place. This may not tell you if they are out of square but will tell you if it's in on one side. If the X measurements check out from a cowl mounting point on top to a mounting part on the radiator support edge and the lower unibody checks out from a hole in the torque box area to the lower radiator support fixture holes you should be good to go. I hope this helps.........Chris

[67gta289]

Richard,

chirp...chirp...this is on my list of things to do for you since mine is apart and was never hit (all original sheet metal).

I might need a gentle reminder on Sunday if you don't see a reply - send me a PM nudge if that happens.

John

[67gtasanjose]

The easiest way that I have found to measure the shock tower alignment is using an original export brace and bolting it up. This serves as a fixture and if your towers are out of alignment it will not bolt up. The lower cross brace (commonly called the belly bar) is another part to install to see if the lower rails are in place. This may not tell you if they are out of square but will tell you if it's in on one side. If the X measurements check out from a cowl mounting point on top to a mounting part on the radiator support edge and the lower unibody checks out from a hole in the torque box area to the lower radiator support fixture holes you should be good to go. I hope this helps.........Chris

I do have an original FORD Export brace to assist in this area but unfortunately, that alone would be then ASSUMING I had the crack welded up correctly on the right side and ASSUMING the tower isn't twisted at all from what originally "totalled out" this car back around '78. This car was sideswiped and the upper control arm hadn't "visually" took a hit but the lower arm was ripped from the strut rod and the wheel was driven back. At the time, all that was replaced (suspension wise) was the lower arm, strut rod and right side tie rods. A few other "wearable" items (lower arm bushings, sway bushings & strut rod bushings) and it took to a good wheel alignment. Fast forward from '78 to 1997 and a crack had shown up in the shock tower. The crack began at the upper control arm forward bolt, and went forwards and began (about 1/2") aoround the front side of the shock tower. As mentioned earlier, I pressed the area in using a port-power to close the gap and have it welded. It LOOKS good (no visable welds at the crack) but it could be off some.

Richard,

chirp...chirp...this is on my list of things to do for you since mine is apart and was never hit (all original sheet metal).

I might need a gentle reminder on Sunday if you don't see a reply - send me a PM nudge if that happens.

John

John, that would be great. It would be also great to have other input from other members since I am sure the way these cars were built, the measurements found will be all over the place. Looking for what is conceivably "normal"

Thanks for input guys!

[cobrajetchris]

Well then, I ASSUME you have it covered and by the way welding up a shock tower is a band aid in my opinion and should be replaced, but I ASSUME you know that!

[67gtasanjose]

Well then, I ASSUME you have it covered and by the way welding up a shock tower is a band aid in my opinion and should be replaced, but I ASSUME you know that!

lol! No Chris, not covered just yet, still fishing for the measurements.
As far as the "band aid", yes I do ASSUME the limitations of rewelding such an item. I appreciate you mentioning it because there are some who might think of welding one as a permanent repair only to have it crack again too. I have seen that before.  I have definately considered replacing the tower too. I thought about it long and hard but in conclusion, for my intended (show) purposes it would be serious over-kill to replace it. I imagine it could crack again one day and I might have to go back in to replace it at a later date. That would be highly irritating I am sure. I suppose it helps me in knowing that the particular person that welded this for me is skilled beyond 95% of most people claiming to be a welder. I "do" welding, I even do welding for hire at times when a job at work requires it, though I do NOT consider myself a "welder". This is the kind of job I would never attempt doing myself. This guy who did, could work for say NASA doing aerospace projects...He is very good at what he does. Since he told me "It will never break again", I believe him! ...and since it is primarily undetectable upon sight, why would I mess with it?

Thanks, I love the humor in your answers too!

[cobrajetchris]

Ok, Now we both got our sarcasm out of the way let's get back to the real issue. You mentioned that you had the car aligned. Did the alignment come into specification at that time? If the upper control arm is in it would be showing negative camber. The strut rod adjustment for your caster that looks unequal like you mentioned may be the rt. lower control arm mounting at rt. frame rail is back a little, especially if it was torn off in an accident. You may want to do a comparison measurement there. I agree with you if the crack was minor it's probably the best repair however I have seen some cars with large welds going up down and around shock towers that is not a good repair.

[67gtasanjose]

Ok, Now we both got our sarcasm out of the way let's get back to the real issue. You mentioned that you had the car aligned. Did the alignment come into specification at that time? If the upper control arm is in it would be showing negative camber. The strut rod adjustment for your caster that looks unequal like you mentioned may be the rt. lower control arm mounting at rt. frame rail is back a little, especially if it was torn off in an accident. You may want to do a comparison measurement there. I agree with you if the crack was minor it's probably the best repair however I have seen some cars with large welds going up down and around shock towers that is not a good repair.

Yes, the first alignment in '78, which was AFTER the initial "accident repair", everything was just fine. (done at a K-mart, so who knows It was aligned again in the mid-80's by me at the dealership I was the working at. (brakes, alignments suspension was my job there) and everything then was good. Many more miles later is when the crack was noticed (mid-90's) and alignment job following the welding is when things went wrong. As I said, we did get it to go down the road straight but had to adjust that strut rod quite a ways to get it in. I feel something is off and NOW is the best time if ever, to get it corrected. (pout  ~even if I MUST change out the shock tower)

[67gta289]

Here's what I measure:
    1a.) LH Shock Tower, upper arm forward hole to Idler arm lower hole= 31-7/8" (32-1/16")
    1b.) LH Shock Tower, upper arm forward hole to Idler arm upper hole= 30-7/8" (31-1/16")  Same 1" difference.

    2a.) RH Shock Tower, upper arm forward hole to Steering gear lower hole= 31-1/4" (31-1/8")
    2b.) RH Shock Tower, upper arm forward hole to Steering gear upper hole= 30-1/4" (30-1/8")

    3a&b) Distance between upper control arm forward bolt hole (Right Side to Left Side) and upper control arm rear holes (also side to side) both measure the same at this time. 27-1/2" (27-3/8" both)

Sending you a PM

edited dimensions from original post.

[mtinkham]

Rather than starting a new thread, I thought I might ask my questions in this thread.

From the Library, I found the frame measurement diagram and I have attached a portion of that diagram for my questions - thank you for making this available.

In the side view, measurements are provided for "B", steering gear mounting hole and "C", idler arm bracket hole.

Can anyone tell me which of the three (3) steering gear mounting holes "B" represents?

Can anyone tell me which of the two (2) idler arm bracket holes "C" represents?

Thank you in advance,
Mark

[J_Speegle]

Rather than starting a new thread, I thought I might ask my questions in this thread.

From the Library, I found the frame measurement diagram and I have attached a portion of that diagram for my questions - thank you for making this available.

In the side view, measurements are provided for "B", steering gear mounting hole and "C", idler arm bracket hole.

Can anyone tell me which of the three (3) steering gear mounting holes "B" represents?

Can anyone tell me which of the two (2) idler arm bracket holes "C" represents?

Mark can't be certain since it's not my drawing I did but would guess that the picture below might be correct. Would measure all three and if one is way off then it may be the wrong hole (b). Shame that they did not include in the drawing all three holes to cut down on the possible and apparent confusion
Hope this helps in some way

[jmlay]

Looking at the 69 diagram, 70 diagram & getting the tape measure out and looking at my car, on a fixture right now:

B = forward most "lower" steering box mounting hole, driver side
C = lower idler arm hole on the passenger side

[J_Speegle]

Looking at the 69 diagram, 70 diagram & getting the tape measure out and looking at my car, on a fixture right now:

B = forward most "lower" steering box mounting hole, driver side
C = lower idler arm hole on the passenger side

Thanks that may help him. As suggested a measurement of both forward holes would likely tell the tale

[mtinkham]

Thank you for the guidance.